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WO2016179759A1 - 一种干扰抵消方法及设备 - Google Patents

一种干扰抵消方法及设备 Download PDF

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Publication number
WO2016179759A1
WO2016179759A1 PCT/CN2015/078597 CN2015078597W WO2016179759A1 WO 2016179759 A1 WO2016179759 A1 WO 2016179759A1 CN 2015078597 W CN2015078597 W CN 2015078597W WO 2016179759 A1 WO2016179759 A1 WO 2016179759A1
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WO
WIPO (PCT)
Prior art keywords
interference
signal
matrix
channel
feature
Prior art date
Application number
PCT/CN2015/078597
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English (en)
French (fr)
Inventor
吕捷
Original Assignee
华为技术有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
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Publication date
Application filed by 华为技术有限公司 filed Critical 华为技术有限公司
Priority to CN201580001376.7A priority Critical patent/CN107079374B/zh
Priority to PCT/CN2015/078597 priority patent/WO2016179759A1/zh
Publication of WO2016179759A1 publication Critical patent/WO2016179759A1/zh

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    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04WWIRELESS COMMUNICATION NETWORKS
    • H04W40/00Communication routing or communication path finding
    • H04W40/02Communication route or path selection, e.g. power-based or shortest path routing
    • H04W40/12Communication route or path selection, e.g. power-based or shortest path routing based on transmission quality or channel quality
    • H04W40/16Communication route or path selection, e.g. power-based or shortest path routing based on transmission quality or channel quality based on interference

Definitions

  • the present invention relates to the field of communications technologies, and in particular, to an interference cancellation method and device.
  • WLAN Wireless Local Area Network
  • Wi-Fi wireless local area network
  • Wi-Fi wireless local area network
  • LAA Licensed-Assisted Access
  • WLAN includes WIreless-FIdelity (Wi-Fi), Bluetooth, Zigbee, Licensed-Assisted Access (LAA) and other wireless transmission technologies, all using high-frequency radio frequency as transmission. medium.
  • each frequency band of the high-frequency radio frequency band carries various wireless applications, including Wi-Fi, radar, Bluetooth, Zigbee, LAA, etc.
  • different protocols interact and interfere with each other, so in the WLAN system, even the same Wi-Fi protocol, data between different wireless access points (APs) will also affect each other, in addition, some household appliances, such as microwave ovens, toy remote controls, maternal and child monitoring equipment will also produce high Frequency interference.
  • APs wireless access points
  • some household appliances such as microwave ovens, toy remote controls, maternal and child monitoring equipment will also produce high Frequency interference.
  • the Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) mechanism is usually adopted to prevent multiple users from simultaneously transmitting data. Interference caused by conflict.
  • CSMA/CA Carrier Sense Multiple Access with Collision Avoidance
  • each station In CSMA/CA, each station first listens to whether the channel is idle before starting to transmit data. If the channel is detected to be idle, the station starts to wait for a random backoff period, during which time it continues channel interception, if it waits until At the end of the time period, the channel is still idle, then the station starts transmitting; if the channel is heard to be busy, the station must delay until the end of the current transmission, and then choose a random backoff period, and continue to listen during this time, if At the end of the waiting period, the channel is still idle and the station starts transmitting. In this way, The CAMA/CA mechanism can avoid sending data when interference occurs to avoid "pollution" of the transmitted content being disturbed.
  • the CSMA/CA mechanism has a certain mitigation effect on the interference, it also has the following drawbacks: if the interference occurs after the start of the transmission of the data, the backoff mechanism will be invalid before the end of the transmission of the data, and the receiving device will receive the interference. The data will still be disrupted by interference, reducing the reliability of data transmission.
  • the invention provides an interference cancellation method and device for canceling interference in data received by a receiving device and improving reliability of data transmission.
  • an embodiment of the present invention provides an interference cancellation method, which is applied to a receiving device, where the receiving device is configured with Nr receiving antennas for receiving Nt transmit antennas or spatial stream or spatial time stream output signals.
  • the Nr is an integer greater than or equal to 2
  • the Nt is an integer greater than or equal to 1; the method includes:
  • the first signal includes Nt transmit antennas received by Nr receive antennas or signals and noise signals after spatial or spatial time stream output signals pass through the channel;
  • the interference cancellation matrix includes M interference cancellation vectors, each interference cancellation vector includes Nr interference cancellation coefficients, and each of the interference cancellation vectors and the N interference sources are received in Nr
  • the correlation degree of the interference feature vector on the antenna is smaller than the first preset threshold; the M is the number of preset interference cancellation vectors; the N is the number of preset interferences;
  • the interference cancellation matrix is multiplied by the first signal, and the multiplied signal is demodulated to obtain a data stream.
  • the acquiring an interference cancellation matrix includes:
  • the interference feature is composed of N vectors, and the ith vector is an interference feature vector of the ith interference source on the Nr receiving antennas;
  • the channel characteristics and the interference Feature acquisition interference cancellation vectors include:
  • the acquiring the interference cancellation matrix according to the channel feature and the interference feature includes:
  • M vectors corresponding to the channel features in the inverse matrix or M linearly combined vectors corresponding to the channel features are combined into the interference cancellation matrix.
  • performing a matrix inversion operation on the first joint matrix, and obtaining an inverse matrix includes:
  • the M vectors corresponding to the maximum signal to noise ratio or The M linear combined vectors corresponding to the maximum signal to noise ratio are combined into the interference cancellation matrix.
  • the method further includes:
  • the V matrix is transmitted to the transmitting device such that the transmitting device sets precoding coefficients according to the V matrix.
  • the acquiring the interference cancellation matrix according to the channel feature and the interference feature includes:
  • a matrix conjugate of the M vectors corresponding to the channel features in the U matrix is transposed as the interference cancellation matrix.
  • any one of the interference feature vectors, before the acquiring the interference feature vector further includes:
  • the third signal is an interference signal, recording an interference feature vector of the third signal on the Nr receiving antennas;
  • the acquiring the interference feature vector includes:
  • the acquiring the interference feature vector includes:
  • the weighted summed result is recorded as an interference feature vector of the third signal on the Nr receive antennas.
  • the determining that the third signal is an interference signal includes:
  • Demodulating the third signal if at least one domain of the demodulated data frame is the same as a domain of the preset interference source, determining that the third signal is an interference signal.
  • the determining that the third signal is an interference signal includes:
  • the third signal is an interference signal.
  • the method further includes:
  • the multiplying the interference cancellation matrix by the first signal specifically includes:
  • the interference cancellation matrix is multiplied by the first signal.
  • the method further includes :
  • the channel feature that sends the second signal includes:
  • the channel characteristic of the second signal is estimated according to the second signal.
  • an embodiment of the present invention provides a receiving device, where the receiving device is configured with Nr receiving antennas for receiving signals of Nt transmitting antennas or spatial streams or spatial time stream outputs, where the Nr is greater than or equal to 2 An integer of the above; Nt is an integer greater than or equal to 1;
  • a receiving unit configured to receive a first signal, where the first signal includes Nt transmit antennas received by the Nr receive antennas or signals and noise signals after the spatial stream or spatial time stream output signals pass through the channel;
  • An acquiring unit configured to acquire an interference cancellation matrix;
  • the interference cancellation matrix includes M interference cancellation vectors, each interference cancellation vector includes Nr interference cancellation coefficients, and each of the interference cancellation vectors interferes with any one of the N interference sources
  • the correlation degree of the interference feature vector of the source on the Nr receiving antennas is smaller than the first preset threshold;
  • the M is the number of preset interference cancellation vectors;
  • the N is the number of preset interferences;
  • An interference cancellation unit is configured to multiply the interference cancellation matrix by the first signal, and demodulate the multiplied signal to obtain a data stream.
  • the receiving unit is further configured to receive a second signal in a first receiving period, where the second signal is received by Nr receiving antennas Signal to;
  • the receiving device further includes:
  • a channel estimation unit configured to estimate, according to the second signal received by the receiving unit, a channel feature of a channel for transmitting the second signal; wherein the channel feature is a matrix of Nr by Nt;
  • the obtaining unit is specifically configured to:
  • the interference feature is composed of N vectors, and the ith vector is an interference feature vector of the ith interference source on the Nr receiving antennas;
  • the acquiring unit is specifically configured to:
  • the acquiring unit is specifically configured to:
  • M vectors corresponding to the channel features in the inverse matrix or M linearly combined vectors corresponding to the channel features are combined into the interference cancellation matrix.
  • the acquiring unit is specifically configured to:
  • the M vectors corresponding to the maximum signal to noise ratio or the M linear combined vectors corresponding to the maximum signal to noise ratio are combined into the interference cancellation matrix.
  • the receiving device further includes:
  • a decomposing unit configured to combine the channel feature estimated by the channel estimating unit and the interference feature acquired by the acquiring unit into the first before acquiring the interference cancellation matrix according to the channel feature and the interference feature Two joint matrix H';
  • a sending unit configured to send, to the sending device, the V matrix decomposed by the decomposition unit, so that the sending device sets the precoding coefficient according to the V matrix.
  • the acquiring unit is specifically configured to:
  • a matrix conjugate of the M vectors corresponding to the channel features in the U matrix is transposed as the interference cancellation matrix.
  • a seventh implementable manner of the second aspect in combination with the first implementable manner of the second aspect to any one of the sixth implementable manners of the second aspect, for the interference feature Any one of the interference feature vectors, before the acquisition unit acquires the interference feature vector,
  • the receiving unit is further configured to receive a third signal in a second receiving period
  • the acquiring unit is further configured to: if it is determined that the third signal received by the receiving unit is an interference signal, record an interference feature vector of the third signal on the Nr receiving antennas;
  • the weighted summed result is recorded as an interference feature vector of the third signal on the Nr receive antennas.
  • the acquiring unit is specifically configured to:
  • the third signal Demodulating the third signal if at least one domain of the demodulated data frame The same as the domain of the preset interference source, it is determined that the third signal is an interference signal.
  • the acquiring unit is specifically configured to:
  • the third signal is an interference signal.
  • the receiving device further includes :
  • a calculating unit configured to calculate, before the interference cancellation unit multiplies the interference cancellation matrix by the first signal, a channel feature of each interference feature vector in the interference matrix and a channel transmitting the first signal The relevance of each row vector or column vector;
  • the interference cancellation unit is specifically configured to:
  • the interference cancellation matrix is multiplied by the first signal.
  • the interference cancellation unit is further configured to:
  • the channel estimation unit estimates the channel characteristic of the second signal according to the second signal, receiving the second signal with a pre-stored first interference cancellation vector to cancel the interference in the second signal ;
  • the channel estimation unit is specifically configured to:
  • the channel characteristic of the second signal is estimated according to the second signal.
  • an embodiment of the present invention provides a receiving device, where the receiving device is configured with Nr receiving antennas for receiving signals of Nt transmitting antennas or spatial streams or spatial time streams, where the Nt is greater than or equal to 2.
  • Nr receiving antennas for receiving signals of Nt transmitting antennas or spatial streams or spatial time streams, where the Nt is greater than or equal to 2.
  • An integer, the Nt being an integer greater than or equal to 1;
  • the transceiver is configured to receive the first signal, where the first signal includes Nt transmit antennas received by the Nr receive antennas or signals and noise signals after the spatial stream or spatial time stream output signals pass through the channel;
  • the interference cancellation matrix includes M interference cancellation vectors, each interference cancellation vector includes Nr interference cancellation coefficients, and each of the interference cancellation vectors interferes with any one of N interference sources
  • the correlation degree of the interference feature vector of the source on the Nr receiving antennas is smaller than the first preset threshold; the M is the number of preset interference cancellation vectors; the N is the number of preset interferences;
  • An interference cancellation unit is configured to multiply the interference cancellation matrix by the first signal, and demodulate the multiplied signal to obtain a data stream.
  • the transceiver is further configured to receive a second signal in a first receiving period, where the second signal is received by Nr receiving antennas Signal to;
  • the processor is specifically configured to:
  • the interference feature is composed of N vectors, and the ith vector is an interference feature vector of the ith interference source on the Nr receiving antennas;
  • the processor is specifically configured to:
  • M vectors corresponding to the channel features in the inverse matrix or M linearly combined vectors corresponding to the channel features are combined into the interference cancellation matrix.
  • the processor is specifically configured to:
  • the M vectors corresponding to the maximum signal to noise ratio or the M linear combined vectors corresponding to the maximum signal to noise ratio are combined into the interference cancellation matrix.
  • the processor is further configured to:
  • the processor Before the processor acquires the interference cancellation matrix according to the channel feature and the interference feature, combining the channel feature estimated by the processor with the interference feature acquired by the processor into a second joint matrix H';
  • the transceiver is further configured to send, to the sending device, the V matrix decomposed by the processor, so that the sending device sets precoding coefficients according to the V matrix.
  • the processor is specifically configured to:
  • a matrix conjugate of the M vectors corresponding to the channel features in the U matrix is transposed as the interference cancellation matrix.
  • a seventh implementable manner of the third aspect in combination with the first implementable manner of the third aspect to any one of the sixth implementable manners of the third aspect, for the interference feature Any of the interference feature vectors, before the processor acquires the interference feature vector,
  • the transceiver is further configured to receive a third signal during a second receiving period
  • the processor is further configured to: if it is determined that the third signal received by the transceiver is an interference signal, record an interference feature vector of the third signal on the Nr receiving antennas;
  • the weighted summed result is recorded as an interference feature vector of the third signal on the Nr receive antennas.
  • the processor is specifically configured to:
  • Demodulating the third signal if at least one domain of the demodulated data frame is the same as a domain of the preset interference source, determining that the third signal is an interference signal.
  • the processor is specifically configured to:
  • the third signal is an interference signal.
  • the processor is further configured to calculate, after the processor multiplies the interference cancellation matrix by the first signal, each interference feature vector in the interference matrix and a channel that transmits the first signal. The correlation of each row vector or column vector of the channel feature;
  • the interference cancellation matrix is multiplied by the first signal.
  • the processor is further configured to:
  • the processor estimates the channel feature of the second signal according to the second signal, receiving the second signal with a pre-stored first interference cancellation vector to cancel interference in the second signal;
  • the channel characteristic of the second signal is estimated according to the second signal.
  • an embodiment of the present invention provides an interference cancellation method and device. After receiving the first signal, the obtained interference cancellation matrix is multiplied by the first signal, and the multiplied signal is demodulated to obtain M. The data stream is used to cancel the interference in the M data streams, so that the data obtained after demodulation is used to cancel the interference data, which greatly improves the reliability of the data transmission.
  • FIG. 1 is a schematic diagram of a channel model of a WLAN system
  • FIG. 2 is a schematic block diagram of interference cancellation according to an embodiment of the present invention.
  • 2A is a schematic block diagram of another interference cancellation according to an embodiment of the present invention.
  • FIG. 3 is a flowchart of an interference cancellation method according to an embodiment of the present invention.
  • FIG. 4 is a schematic diagram of a signal format in a receiving period according to an embodiment of the present invention.
  • FIG. 5 is a structural diagram of a receiving device 50 according to an embodiment of the present invention.
  • FIG. 5 is a structural diagram of a receiving device 50 according to an embodiment of the present invention.
  • FIG. 5B is a structural diagram of a receiving device 50 according to an embodiment of the present invention.
  • FIG. 5C is a structural diagram of a receiving device 50 according to an embodiment of the present invention.
  • FIG. 6 is a structural diagram of a receiving device 60 according to an embodiment of the present invention.
  • the interference cancellation method provided by the embodiment of the present invention is applicable not only to the WLAN system, but also to other communication systems that use the multi-antenna receiving technology.
  • the comparison of the present invention is not limited, and the present invention only uses the WLAN system as an example. Be explained.
  • the WLAN channel and channel model are as shown in FIG. 1.
  • signals between the receiving device and the transmitting device can be transmitted through multiple paths without interference from interference sources.
  • the number can be an Nt dimension vector (x1, x2, ..., xNt), where Nt can be the number of transmitting antennas, the number of spatial streams transmitted, or the space to be transmitted.
  • a spatial stream may be a bit stream or a modulation symbol stream transmitted in multiple spatial dimensions; a spatial time stream may be spatially combined and temporarily processed by one or more spatial streams.
  • the stream of modulation symbols; in general, user data can be divided into multiple Nt spatial streams for transmission on a transmit antenna greater than or equal to Nt. For example, a weak signal is divided into two spatial streams and then two spatial streams.
  • the signal is spatially time block coded (STBC) processed into four spatial time stream signals, and then further processed into four transmit antenna transmit signals, then the transmit signal x can be two spatial stream signals, or four empty Time signal stream, a signal may be transmitted four transmission antennas.
  • STBC spatially time block coded
  • Hij is the channel characteristic between the jth transmit antenna or spatial stream or spatial time stream to the ith receive antenna:
  • the IC is an interference feature (also referred to as an interference channel), and may be represented as a matrix of N N-dimensional row vectors or column vectors, which is not limited in this embodiment of the present invention.
  • the IC is a matrix composed of N N-dimensional column vectors as shown below, wherein the j-th column vector is the interference characteristic of the j-th interference source:
  • the receiving device first undergoes amplitude adjustment, in-phase/quadrature (I/Q) signal detection, and fast Fourier.
  • the Four Fourier Transformation (FFT) process receives the frequency domain signal, and the frequency domain signal corresponding to one data stream is (y1,...,yNr), and then uses an interference cancellation vector to perform interference cancellation on the signal (as shown in the figure).
  • 2 shows the useful data stream after demodulation processing; similarly, when the receiving device needs to obtain multiple data streams at the same time (as shown in FIG. 2A), it can respectively use the corresponding data stream.
  • An interference cancellation vector is multiplied by the signal vector y to perform interference cancellation, obtain a cancellation signal of the plurality of data streams, and demodulate the process to obtain a plurality of data streams.
  • the present invention can perform interference cancellation on the frequency domain signal, and can also perform interference cancellation on the time domain signal. This is not limited.
  • the present invention only uses interference cancellation for the frequency domain signal as an example.
  • the present invention is applicable not only to the receiving device of the IEEE 802.11 series standard, but also to the receiving device of other standards (such as Bluetooth, LAA), regardless of the standard receiving device, the interference cancellation The principle is the same.
  • the interference cancellation method provided by the present invention will be described below by way of an embodiment.
  • FIG. 3 is a flowchart of an interference cancellation method according to an embodiment of the present invention, which is applied to a receiving device, where the receiving device is configured with Nr receiving antennas for receiving Nt transmit antennas or spatial streams or spatial time streams. (space-time stream) output signal, the Nr is an integer greater than or equal to 2, the Nt is an integer greater than or equal to 1; the receiving device may be a workstation device, such as: mobile phone, computer, smart TV, video box And other devices; for example, a wireless router, a digital subscriber line customer premise device (DSL CPE), a terminal device (Cable Modem, CM for short), an optical network unit (Optical)
  • DSL CPE digital subscriber line customer premise device
  • CM Compact Modem
  • Optical optical network unit
  • a device such as a network unit (ONU); as shown in FIG. 3, the method may include:
  • a receiving device can receive at least two parts of signals in a receiving period: a first part signal and a second part signal; wherein the first part of the signal is demodulated to obtain a corresponding multiple
  • preamble words also known as protocol headers
  • the second part of the signal can Demodulation by different demodulation methods to obtain multiple data streams.
  • FIG. 4 shows a signal receiving format in one receiving cycle of the 802.11n series of standards.
  • the signal may include: a first partial signal and a second partial signal; wherein the first partial signal is solved After adjustment, it can be obtained by: Short Training Field (STF), Domain Message (SIG), and Long Training Field (LTF) information.
  • STF can be used for idle channel estimation (Clear).
  • the SIG can be used to determine whether the signal is an interference signal
  • the LTF can be used to estimate the channel characteristics
  • the second part of the signal can be demodulated to obtain the data (Data).
  • the interference cancellation matrix includes M interference cancellation vectors, each interference cancellation vector includes Nr interference cancellation coefficients, and each of the interference cancellation vectors and any one of the N interference sources is in Nr.
  • the correlation of the interference feature vectors on the receiving antennas is smaller than the first preset threshold; the M is the number of preset interference cancellation vectors; and the N is the number of preset interferences.
  • M may be set as needed, and may be one or more.
  • the interference cancellation matrix in step 302 only includes one interference cancellation vector, that is, the interference cancellation matrix can be regarded as an interference cancellation vector.
  • the number of the interference sources N may be obtained according to the statistical measurement of the interference situation in the environment in which the receiving device is located, and may be an interference source or a plurality of interference sources, which is not limited in the embodiment of the present invention.
  • the correlation between the vectors may refer to: the angle between the vectors, which may be represented by the cosine of the vector angle or the absolute value of the cosine of the vector angle; if the correlation is close to 0 degrees Or 180 degrees, indicating that the vectors are nearly parallel, and the correlation between the vectors; if the correlation is close to 90 degrees, it means that the vectors are close to vertical, and the vectors are not related; usually, cosine correlation, Pearson can be used. A commonly used calculation method such as the Pearson correlation coefficient obtains the correlation between vectors.
  • the first preset threshold may be set as follows to zero or equal to zero (ideally) as needed, and the correlation between the interference cancellation vector and each of the interference features in the interference feature is less than a first preset threshold.
  • the threshold value indicates that there is a certain correlation between the interference cancellation vector and the interference feature corresponding to each interference source, and the interference cancellation vector cannot be used to cancel the interference of the interference source.
  • the receiving device may obtain the interference cancellation matrix by using the following method:
  • the interference feature is composed of N vectors, and the ith vector is an interference feature vector of the ith interference source on the Nr receiving antennas;
  • the second signal is a first part of the first receiving period, and after demodulation, can be used to indicate the arrival of the data, indicate the format of the data stream, estimate the channel characteristics, estimate the received signal energy intensity, estimate the frequency error, and time.
  • the preamble word of the error or the like may be in the first receiving period simultaneously with the first signal, or may be in the first receiving period before the receiving period of the first signal; when receiving at the first signal.
  • the interference cancellation vector in the interference cancellation matrix for canceling the data stream after demodulation of the first signal is a historically stored interference cancellation vector, instead of the first received according to the current reception period.
  • the interference cancellation matrix is obtained according to the channel feature and the acquired interference feature; if the second signal is an interference signal, recording the interference feature of the second signal, ending the subsequent one of the first receiving period
  • the receiving process monitors the signal in the next receiving period; it should be noted that this embodiment
  • the estimation of the channel characteristics in step 302 can be performed in the prior art, and details are not described herein again.
  • the receiving device may use the interference feature vector of the pre-recorded interference signal as the interference feature vector in the interference feature, and then combine the recorded N interference feature vectors into the interference feature.
  • the interference feature vector of the pre-recorded interference signal as the interference feature vector in the interference feature, and then combine the recorded N interference feature vectors into the interference feature.
  • the third signal is an interference signal, recording an interference feature vector of the third signal on the Nr receiving antennas;
  • the weighted summed result is recorded as an interference feature vector of the third signal on the Nr receive antennas.
  • the second receiving period may be any receiving period before the first receiving period.
  • whether the third signal is an interference signal can be determined by any one of the following (1), (2), and (3):
  • the data frame may be a physical (MAC) layer frame or a higher-level service frame (such as an IP packet); the domain may be an address field of the data frame, for example, the domain of the 802.11 MAC frame may be a destination address or a source address.
  • the IP packet field may be any address included in the IP packet, or may be an identifier for identifying the WLAN, such as: Service Set Identification (SSID), Basic Service Set Identification (abbreviation) BSSID) and so on.
  • SSID Service Set Identification
  • BSSID Basic Service Set Identification
  • the third signal is demodulated into a MAC frame, and the destination address is A1, it is determined that the third signal is an interference signal.
  • the third signal is an interference signal.
  • the data stream information is information necessary for demodulating the signal to obtain the data stream, including: Modulation and Coding Scheme (MCS), channel bandwidth, and space-time block coding (STBC) technology. Forward Error Correction (FEC) coding method, etc.
  • MCS Modulation and Coding Scheme
  • STBC space-time block coding
  • FEC Forward Error Correction
  • the receiving device may further select, as the interference feature, an interference feature vector corresponding to the N different interference sources from the pre-stored interference feature set, where the interference feature set records the interference feature vector corresponding to the multiple types of the interference source.
  • the interference feature vector corresponding to the interference source can be obtained according to the interference feature vector of the interference signal recorded multiple times, for example:
  • the preset threshold value may be set as needed, and the comparison in the embodiment of the present invention is not limited; the calculation of the correlation degree may adopt the prior art, and details are not described herein again.
  • the interference feature set may further include: an occupied channel time or a signal energy corresponding to each type of interference source; optionally, the receiving device may further select an interference feature vector corresponding to the N different interference sources from the pre-stored interference feature set.
  • the method may include:
  • the receiving device selects, as the interference feature, an interference feature vector corresponding to N different interference sources occupying the longest channel time or the highest signal energy from the pre-stored interference feature set.
  • the receiving device may be based on the channel feature and the method according to any one of (a) orthogonal method, (b) matrix inversion, and (c) ⁇ matrix decomposition.
  • the interference feature acquires the interference cancellation matrix:
  • one or more interference cancellation vectors may be calculated by using an orthogonal method, and the interference cancellation vectors are combined into an interference cancellation matrix, wherein the process of obtaining the interference cancellation vector by the orthogonal method is adopted. details as follows:
  • the vertical direction of the phase may be approximately 90 degrees vertical or completely 90 degrees vertical (ideal state); the preset angle may be set as needed, and details are not described herein again.
  • M vectors corresponding to the channel features in the inverse matrix or M linearly combined vectors corresponding to the channel features are combined into the interference cancellation matrix.
  • the M vectors corresponding to the channel feature may be: a vector in which the column (row) number sequence number is equal to the number of rows (columns) in which the channel feature corresponding to the data stream that needs to cancel the interference in the channel feature is equal; For example, if the number of data streams that need to cancel the interference is M, and the data stream in the channel matrix that needs to cancel the interference corresponds to the second column and the third column of the first joint matrix, then the second row and the third row in the inverse matrix The vector combination of the rows forms an interference cancellation matrix.
  • the linear combination may be a multiplication of a vector included in the channel matrix by a coefficient, and the coefficient is a scaling factor, and the amplitude of the vector may be adjusted to a certain range to avoid introducing an excessively large fixed-point error.
  • the matrix inversion operation may be performed on the first joint matrix. inverse.
  • the first joint matrix may be subjected to multiple approximate inversions, and a pre-M row vector satisfying the requirement is selected as the interference cancellation.
  • the matrix is as follows:
  • the M vectors corresponding to the maximum signal to noise ratio or the M linear combined vectors corresponding to the maximum signal to noise ratio are combined into the interference cancellation matrix.
  • the interference feature may be added to the column behind the joint channel matrix, or may be added to the column in front of the joint channel matrix;
  • (H1i, H2i, ..., HNri) is the channel corresponding to the i-th data stream.
  • the characteristics, (IC1i, IC2i, ..., ICNri) are the i-th interference characteristics to be interfered with.
  • the first M row vector in the inverse matrix H' -1 is taken as the interference cancellation matrix C to cancel the interference in the M data streams, or the inverse matrix H' -1
  • the pre-M line vector is multiplied by the coefficient D as the interference cancellation matrix C:
  • D is a diagonal matrix, which is a scaling factor that adjusts the amplitude of C to a certain range to avoid introducing excessive fixed-point errors.
  • H ' is the number of rows of the matrix, is not equal to the number of columns, or H' matrix of full rank, it is possible to find the pseudo-inverse H 'L.
  • H' -1 can be subjected to multiple approximate inversions, and a interference cancellation matrix that satisfies the requirements can be selected, as follows:
  • the interference cancellation matrix corresponding to the maximum signal to noise ratio is used as the interference cancellation matrix C.
  • the letter can be calculated according to the following formula Signal to noise ratio SNR:
  • diag indicates that the matrix is diagonal, x is the transmitted signal, diag(C ⁇ H) ⁇ x is the useful signal after canceling the interference, and non-diag(C ⁇ H) ⁇ x is the interference between the useful signals;
  • sumByRow means summation by row, sumByRow(C ⁇ IC+C ⁇ BNG) is the interference of interference source and noise, and BNG is the background noise amplitude received by each antenna in the system.
  • the V matrix is transmitted to the transmitting device such that the transmitting device sets the precoding coefficients according to the V matrix.
  • the matrix conjugate of the U matrix and the M vector combinations corresponding to the channel feature is transposed as the interference cancellation matrix.
  • the M vectors corresponding to the channel feature may be: a vector in which the column (row) number sequence number is equal to the number of rows (columns) in which the channel feature corresponding to the data stream that needs to cancel the interference in the channel feature is equal;
  • the unitary matrix decomposition can be any decomposition method such as singular value decomposition (SVD) or geometric mean decomposition (GMD).
  • the interference feature may be added to the column behind the joint channel matrix, or may be added to the column in front of the joint channel matrix;
  • (H1i, H2i, ..., HNri) is the channel corresponding to the i-th data stream.
  • the characteristics, (IC1i, IC2i, ..., ICNri) are the i-th interference characteristics to be interfered with.
  • H' U ⁇ S ⁇ V
  • the U and the V are a unitary matrix
  • the S is a diagonal matrix
  • the matrix conjugate composed of the M-column M-column vectors is transposed as the interference cancellation matrix.
  • the method before the interference cancellation matrix is multiplied by the first signal, the method further include:
  • the multiplying the interference cancellation matrix by the first signal specifically includes:
  • the interference cancellation matrix is multiplied by the first signal.
  • the second preset threshold may be set as needed.
  • the comparison in the embodiment of the present invention is not limited. If the correlation is less than the second preset threshold, the interference feature of the interference source is not related to the channel matrix. Using the interference cancellation vector to cancel the interference in the signal does not significantly weaken the strength of the useful signal; if the correlation is greater than or equal to the second preset threshold, it indicates that the interference characteristic of the interference source is related to the channel matrix, and the interference in use The cancellation of the vector cancels the interference in the signal while also weakening the strength of the useful signal in the signal, which is not multiplied by the first signal.
  • CCA Clear Channel Assessment
  • the receiving device may mistake the channel for busy, in order to avoid The receiving device misinterprets the channel occupied by the interference as the busy channel that the transmitting device is transmitting the signal.
  • the received first part of the signal may also be cancelled. For example, taking the second signal as an example, receiving When the second signal arrives, the interference cancellation is:
  • the channel feature that sends the second signal includes:
  • the third preset threshold is greater than or equal to the third preset threshold, determining that the channel is busy, estimating, according to the second signal, a channel characteristic of the second signal; if determining that the signal energy of the first signal after canceling the interference is less than a third preset
  • the threshold determines that the channel is idle, and the channel can be used to send data to the transmitting device.
  • an embodiment of the present invention provides an interference cancellation method. After receiving the first signal, the obtained interference cancellation matrix is multiplied by the first signal, and the multiplied signal is demodulated to obtain M data. The flow is used to cancel the interference in the M data streams, so that the data obtained after demodulation is the data after canceling the interference, which greatly improves the reliability of the data transmission.
  • FIG. 5 is a structural diagram of a receiving device 50 according to an embodiment of the present invention, which is applied to perform the interference cancellation method according to the first embodiment, where the receiving device is configured with Nr receiving antennas for receiving Nt transmissions.
  • An integer; the device can include:
  • the receiving unit 501 is configured to receive a first signal, where the first signal includes The Nt transmit antennas received by the Nr receive antennas or the spatial stream or spatial time stream output signals pass through the channel after the signal and the noise signal.
  • a receiving device can receive at least two parts of signals in a receiving period: a first part signal and a second part signal; wherein the first part of the signal is demodulated to obtain a corresponding multiple
  • preamble words also known as protocol headers
  • the second part of the signal can Demodulation by different demodulation methods to obtain multiple data streams.
  • FIG. 4 shows a signal receiving format in one receiving cycle of the 802.11n series of standards.
  • the signal may include: a first partial signal and a second partial signal; wherein the first partial signal is solved After adjustment, it can be obtained by: Short Training Field (STF), Domain Message (SIG), and Long Training Field (LTF) information.
  • STF can be used for idle channel estimation (Clear).
  • Channel Assesement (CCA) detects the arrival of the received signal.
  • the SIG can be used to determine whether the signal is an interference signal.
  • the LTF can be used to estimate the channel characteristics.
  • the second part of the signal can be demodulated to obtain the data (Data).
  • the obtaining unit 502 is configured to obtain an interference cancellation matrix, where the interference cancellation matrix includes M interference cancellation vectors, each interference cancellation vector includes Nr interference cancellation coefficients, and each of the interference cancellation vectors and any one of the N interference sources
  • the correlation of the interference feature vector of the interference source on the Nr receiving antennas is less than a first preset threshold; the M is a pre- The number of interference cancellation vectors set; the N is the number of interferences set in advance.
  • M may be set as needed, and may be one or more.
  • the interference cancellation matrix in step 302 only includes one interference cancellation vector, that is, the interference cancellation matrix can be regarded as an interference cancellation vector.
  • the number of the interference sources N may be obtained according to the statistical measurement of the interference situation in the environment in which the receiving device is located, and may be an interference source or a plurality of interference sources, which is not limited in the embodiment of the present invention.
  • the correlation between the vectors may refer to: the angle between the vectors, which may be represented by the cosine of the vector angle or the absolute value of the cosine of the vector angle; if the correlation is close to 0 degrees Or 180 degrees, indicating that the vectors are nearly parallel, and the correlation between the vectors; if the correlation is close to 90 degrees, it means that the vectors are close to vertical, and the vectors are not related; usually, cosine correlation, Pearson can be used. A commonly used calculation method such as the Pearson correlation coefficient obtains the correlation between vectors.
  • the first preset threshold may be set as follows to zero or equal to zero (ideally) as needed, and the correlation between the interference cancellation vector and each of the interference features in the interference feature is less than a first preset threshold. Representing that the interference cancellation vector is uncorrelated with the interference feature corresponding to each interference source, and the interference cancellation vector can be used to cancel the interference of the interference source to the greatest extent; the interference cancellation vector and each interference feature vector of the interference feature The correlation degree is greater than or equal to the first preset threshold value, and the interference cancellation vector has a certain correlation with the interference feature corresponding to each interference source, and the interference cancellation vector cannot be used to cancel the interference of the interference source.
  • the interference cancellation unit 503 is configured to multiply the interference cancellation matrix acquired by the acquisition unit by the first signal received by the receiving unit, and demodulate the multiplied signal to obtain a data stream.
  • the receiving device 50 may further include: a channel estimation unit 504;
  • the receiving unit 501 is further configured to receive a second signal in a first receiving period, where the second signal is a signal received by the Nr receiving antennas;
  • the channel estimation unit 504 is configured to estimate, according to the second signal received by the receiving unit, a channel feature of a channel that transmits the second signal; where a matrix of Nr times Nt;
  • the obtaining unit 502 is specifically configured to:
  • the interference feature is composed of N vectors, and the ith vector is an interference feature vector of the ith interference source on the Nr receiving antennas;
  • the acquiring unit 502 further needs to determine, according to the demodulated second signal, whether the second signal is a useful signal, if the second signal is a useful signal. And acquiring, according to the channel feature of the channel for transmitting the second signal, the interference cancellation matrix according to the channel feature and the acquired interference feature; and if the second signal is an interference signal, recording the interference of the second signal Feature, ending the subsequent receiving process in the first receiving period, monitoring the signal in the next receiving period; it should be noted that the useful signal in this embodiment is the signal interfered by the interference source, and may include the signal sent by the transmitting end.
  • the channel estimation unit 504 can estimate channel characteristics by using the prior art, and details are not described herein again.
  • the second signal is a first part of the first receiving period, and after demodulation, can be used to indicate the arrival of the data, indicate the format of the data stream, estimate the channel characteristics, estimate the received signal energy intensity, estimate the frequency error, and time.
  • the preamble word of the error or the like may be in the first receiving period simultaneously with the first signal, or may be in the first receiving period before the receiving period of the first signal; when receiving at the first signal.
  • the interference cancellation vector in the interference cancellation matrix for canceling the data stream after demodulation of the first signal is a historically stored interference cancellation vector, instead of the first received according to the current reception period.
  • the acquiring unit 502 may use the interference feature vector of the pre-recorded interference signal as the interference feature vector in the interference feature, as follows:
  • the receiving unit 501 is further configured to receive a third signal in a second receiving period
  • the obtaining unit 502 is specifically configured to determine whether the third signal is an interference signal
  • the third signal is an interference signal, recording an interference feature vector of the third signal on the Nr receiving antennas;
  • the weighted summed result is recorded as an interference feature vector of the third signal on the Nr receive antennas.
  • the second receiving period may be any receiving period before the first receiving period.
  • the acquiring unit 502 may determine whether the third signal is an interference signal by using any one of the following (1), (2), and (3):
  • the data frame may be a physical (MAC) layer frame or a higher-level service frame (such as an IP packet); the domain may be an address field of the data frame, for example, the domain of the 802.11 MAC frame may be a destination address or a source address.
  • the IP packet field may be any address included in the IP packet, or may be an identifier for identifying the WLAN, such as: Service Set Identification (SSID), Basic Service Set Identification (abbreviation) BSSID) and so on.
  • SSID Service Set Identification
  • BSSID Basic Service Set Identification
  • the third signal is demodulated into a MAC frame, and the destination address is A1, it is determined that the third signal is an interference signal.
  • the third signal is an interference signal.
  • the data stream information is information necessary for demodulating the signal to obtain the data stream, including: Modulation and Coding Scheme (MCS), channel bandwidth, and space-time block coding (STBC) technology. Use, Forward Error Correction (FEC) coding method, etc.
  • MCS Modulation and Coding Scheme
  • STBC space-time block coding
  • FEC Forward Error Correction
  • the receiving device may further select, as the interference feature, an interference feature vector corresponding to the N different interference sources from the pre-stored interference feature set, where the interference feature set records the interference feature vector corresponding to the multiple types of the interference source.
  • the interference feature vector corresponding to the interference source can be obtained according to the interference feature vector of the interference signal recorded multiple times, for example:
  • the preset threshold value is used to record the at least one recorded interference feature vector as the interference feature vector corresponding to the first type of interference source.
  • the preset threshold value may be set as needed, and the comparison in the embodiment of the present invention is not limited; the calculation of the correlation degree may adopt the prior art, and details are not described herein again.
  • the interference feature set may further include: an occupied channel time or a signal energy corresponding to each type of interference source; optionally, the receiving device may further select an interference feature vector corresponding to the N different interference sources from the pre-stored interference feature set.
  • the method may include:
  • the receiving device selects the longest occupied channel from the pre-stored interference feature set. Or the interference feature vector corresponding to the N different interference sources with the highest signal energy as the interference feature.
  • the obtaining unit 502 may be configured according to the channel feature and the interference feature according to any one of (a) orthogonal method, (b) matrix inversion, and (c) ⁇ matrix decomposition described below.
  • the interference cancellation matrix :
  • the obtaining unit 502 may calculate one or more interference cancellation vectors by using an orthogonal method, and combine the interference cancellation vectors into an interference cancellation matrix, as follows:
  • the vertical direction of the phase may be approximately 90 degrees vertical or completely 90 degrees vertical (ideal state); the preset angle may be set as needed, and details are not described herein again.
  • the obtaining unit 502 is specifically configured to:
  • M vectors corresponding to the channel features in the inverse matrix or M linearly combined vectors corresponding to the channel features are combined into the interference cancellation matrix.
  • the M vectors corresponding to the channel feature may be: a vector in which the column (row) number sequence number is equal to the number of rows (columns) in which the channel feature corresponding to the data stream that needs to cancel the interference in the channel feature is equal; For example, if the number of data streams that need to cancel the interference is M, and the data stream in the channel matrix that needs to cancel the interference corresponds to the second column and the third column of the first joint matrix, then the second row and the third row in the inverse matrix The vector combination of the rows forms an interference cancellation matrix.
  • the linear combination may be a vector to be included with the channel matrix With a coefficient, the coefficient is a scaling factor, which can adjust the amplitude of the vector to a certain range to avoid introducing too large fixed-point error.
  • the matrix inversion operation may be performed on the first joint matrix. inverse.
  • the obtaining unit 502 may perform multiple approximate inversions on the first joint matrix, and select a pre-M row vector that satisfies the requirement as a
  • the interference cancellation matrix is as follows:
  • the M vectors corresponding to the maximum signal to noise ratio or the M linear combined vectors corresponding to the maximum signal to noise ratio are combined into the interference cancellation matrix.
  • the interference feature may be added to the column behind the joint channel matrix, or may be added to the column in front of the joint channel matrix;
  • (H1i, H2i, ..., HNri) is the channel corresponding to the i-th data stream.
  • the characteristics, (IC1i, IC2i, ..., ICNri) are the i-th interference characteristics to be interfered with.
  • the first M row vector in the inverse matrix H' -1 is taken as the interference cancellation matrix C to cancel the interference in the M data streams, or the inverse matrix H' -1
  • the pre-M line vector is multiplied by the coefficient D as the interference cancellation matrix C:
  • D is a diagonal matrix, which is a scaling factor that adjusts the amplitude of C to a certain range to avoid introducing excessive fixed-point errors.
  • H ' is the number of rows of the matrix, is not equal to the number of columns, or H' matrix of full rank, it is possible to find the pseudo-inverse H 'L.
  • the H' -1 is subjected to multiple approximate inversions, and a interference cancellation matrix that satisfies the requirements is selected, as follows:
  • the interference cancellation matrix corresponding to the maximum signal to noise ratio is used as the interference cancellation matrix C.
  • the signal to noise ratio SNR of the signal can be calculated according to the following formula:
  • diag indicates that the matrix is diagonal, x is the transmitted signal, diag(C ⁇ H) ⁇ x is the useful signal after canceling the interference, and non-diag(C ⁇ H) ⁇ x is the interference between the useful signals;
  • sumByRow means summation by row, sumByRow(C ⁇ IC+C ⁇ BNG) is the interference of interference source and noise, and BNG is the background noise amplitude received by each antenna in the system.
  • the receiving device may further include: a decomposition unit 505, a sending unit 506, as shown in FIG. 5B;
  • the decomposing unit 505 is configured to combine the channel feature estimated by the channel estimating unit 504 with the interference feature acquired by the acquiring unit 502 into a second joint matrix H';
  • the sending unit 506 is configured to send, to the sending device, the V matrix decomposed by the decomposing unit 505, so that the sending device sets the precoding coefficient according to the V matrix.
  • the obtaining unit 502 is specifically configured to:
  • a matrix conjugate of the U matrix combined with the M vectors corresponding to the channel feature is transposed as the interference cancellation matrix.
  • the M vectors corresponding to the channel feature may be: a vector in which the column (row) number sequence number is equal to the number of rows (columns) in which the channel feature corresponding to the data stream that needs to cancel the interference in the channel feature is equal;
  • the unitary matrix decomposition can be any decomposition method such as singular value decomposition (SVD) or geometric mean decomposition (GMD).
  • the interference feature may be added to the column behind the joint channel matrix, or may be added to the column in front of the joint channel matrix; (H1i, H2i, ..., HNri) is the channel corresponding to the i-th data stream. Characteristics, (IC1i, IC2i, ..., ICNri) Is the i-th interference feature to interfere with the source.
  • H' U ⁇ S ⁇ V
  • the U and the V are a unitary matrix
  • the S is a diagonal matrix
  • the matrix conjugate composed of the M-column M-column vectors is transposed as the interference cancellation matrix.
  • the receiving device can utilize the obtained interference cancellation matrix to cancel the interference in the multiple data streams and provide the reliability of the data transmission.
  • the receiving device may further include: Computing unit 507;
  • the channel estimation unit 504 is further configured to estimate a channel characteristic of a channel that transmits the first signal
  • the calculating unit 507 is configured to calculate, after the interference cancellation unit 503 multiplies the interference cancellation matrix by the first signal, each interference feature vector in the interference matrix and transmit the first signal. The correlation of each row vector or column vector of the channel characteristics of the channel;
  • the interference cancellation unit 503 is specifically configured to:
  • the interference cancellation matrix is multiplied by the first signal.
  • the second preset threshold may be set as needed.
  • the comparison in the embodiment of the present invention is not limited. If the correlation is less than the second preset threshold, the interference feature of the interference source is not related to the channel matrix. Using the interference cancellation vector to cancel the interference in the signal does not significantly weaken the strength of the useful signal; if the correlation is greater than or equal to the second predetermined threshold, it indicates that the interference characteristic of the interference source is related to the channel matrix, Using the interference cancellation vector to cancel the interference in the signal also weakens the strength of the useful signal in the signal, which is not multiplied by the first signal.
  • a clear channel assessment (CCA) is required for the channel of the transmitted signal, and if the channel is a busy channel, the received first partial signal is performed.
  • CCA clear channel assessment
  • the receiving device may mistake the channel for busy, in order to avoid The receiving device misinterprets the channel occupied by the interference as a busy channel that the transmitting device is transmitting a signal.
  • the interference canceling unit 503 is further configured to:
  • the second signal is received by using a pre-stored first interference cancellation vector to cancel the second signal. interference;
  • the channel estimation unit 504 is specifically configured to:
  • the third preset threshold is greater than or equal to the third preset threshold, determining that the channel is busy, estimating, according to the second signal, a channel characteristic of the second signal; if determining that the signal energy of the first signal after canceling the interference is less than a third preset
  • the threshold determines that the channel is idle, and the channel can be used to send data to the transmitting device.
  • the embodiment of the present invention provides a receiving device, after receiving the first signal, multiplying the obtained interference cancellation matrix by the first signal, and demodulating the multiplied signal to obtain M data streams.
  • the data obtained after demodulation is used to cancel the interference data, which greatly improves the reliability of data transmission.
  • FIG. 6 is a structural diagram of a receiving device 60 according to an embodiment of the present invention.
  • the method for performing the interference cancellation method described in Embodiment 1 is as shown in FIG. 6.
  • the device may include: a transceiver 601, a processor 602, a memory 603, and at least one communication bus 604, for implementing between the devices. Connect and communicate with each other;
  • the transceiver 601 may be configured with Nr receiving antennas for receiving Nt transmit antennas or spatial stream or space-time stream output signals, where Nr is an integer greater than or equal to 2;
  • Nr is an integer greater than or equal to 2;
  • the Nt is an integer greater than or equal to 1 for data transmission with an external network element.
  • the processor 602 may be a central processing unit (English: central processing unit, referred to as CPU).
  • the memory 603 may be a volatile memory (English: volatile memory), such as random access memory (English: random-access memory, abbreviation: RAM); or non-volatile memory (English: non-volatile memory), for example Read-only memory (English: read-only memory, abbreviation: ROM), flash memory (English: flash memory), hard disk (English: hard disk drive, abbreviation: HDD) or solid state drive (English: solid-state drive, abbreviation :SSD); or a combination of the above types of memory and providing instructions and data to the processor 602.
  • volatile memory such as random access memory (English: random-access memory, abbreviation: RAM); or non-volatile memory (English: non-volatile memory), for example Read-only memory (English: read-only memory, abbreviation: ROM), flash memory (English: flash memory), hard disk (English: hard disk drive, abbreviation: HDD) or solid state drive (English: solid-state drive, abbreviation :SSD); or a combination
  • the transceiver 601 is configured to receive the first signal, where the first signal includes Nt transmit antennas received by the Nr receive antennas or signals and noise signals after the spatial stream or spatial time stream output signals pass through the channel.
  • a receiving device can receive at least two parts of signals in a receiving period: a first part signal and a second part signal; wherein the first part of the signal is demodulated to obtain a corresponding multiple
  • preamble words also known as protocol headers
  • the second part of the signal can Demodulation by different demodulation methods to obtain multiple data streams.
  • FIG. 4 shows a signal receiving format in one receiving cycle of the 802.11n series of standards.
  • the signal may include: a first partial signal and a second partial signal; wherein the first partial signal is solved After adjustment, it can be obtained correspondingly: short training field (Short Training field, detecting STF), Domain Message (SIG) and Long Training Field (LTF) information, STF can be used for Clear Channel Assesement (CCA) to detect received signals.
  • CCA Clear Channel Assesement
  • the SIG can be used to determine whether the signal is an interference signal
  • the LTF can be used to estimate the channel characteristics
  • the second part of the signal can be demodulated to obtain the data (Data).
  • the processor 602 is configured to acquire an interference cancellation matrix, where the interference cancellation matrix includes M interference cancellation vectors, each interference cancellation vector includes Nr interference cancellation coefficients, and each of the interference cancellation vectors and any one of the N interference sources
  • the correlation of the interference feature vector of the interference source on the Nr receiving antennas is smaller than the first preset threshold; the M is the number of preset interference cancellation vectors; and the N is the number of preset interferences.
  • M may be set as needed, and may be one or more.
  • the interference cancellation matrix in step 302 only includes one interference cancellation vector, that is, the interference cancellation matrix can be regarded as an interference cancellation vector.
  • the number of the interference sources N may be obtained according to the statistical measurement of the interference situation in the environment in which the receiving device is located, and may be an interference source or a plurality of interference sources, which is not limited in the embodiment of the present invention.
  • the correlation between the vectors may refer to: the angle between the vectors, which may be represented by the cosine of the vector angle or the absolute value of the cosine of the vector angle; if the correlation is close to 0 degrees Or 180 degrees, indicating that the vectors are nearly parallel, Correlation between vectors; if the correlation is close to 90 degrees, it means that the vectors are close to vertical, and the vectors are not related; usually, common calculation methods such as cosine correlation and Pearson correlation coefficient can be used. Get the correlation between vectors.
  • the first preset threshold may be set as follows to zero or equal to zero (ideally) as needed, and the correlation between the interference cancellation vector and each of the interference features in the interference feature is less than a first preset threshold. Representing that the interference cancellation vector is uncorrelated with the interference feature corresponding to each interference source, and the interference cancellation vector can be used to cancel the interference of the interference source to the greatest extent; the interference cancellation vector and each interference feature vector of the interference feature The correlation degree is greater than or equal to the first preset threshold value, and the interference cancellation vector has a certain correlation with the interference feature corresponding to each interference source, and the interference cancellation vector cannot be used to cancel the interference of the interference source.
  • the transceiver 601 is further configured to receive a second signal in a first receiving period, where the second signal is a signal received by the Nr receiving antennas;
  • the processor 602 is specifically configured to:
  • the interference feature is composed of N vectors, the N is the number of interference sources, and the ith vector is an interference feature vector of the ith interference source on the Nr receiving antennas;
  • each interference cancellation vector in the interference cancellation matrix and each interference feature vector in the interference feature The correlation is less than the first preset threshold.
  • the interference cancellation matrix is obtained according to the channel feature and the acquired interference feature; if the second signal is an interference signal, recording the interference feature of the second signal, ending the subsequent one of the first receiving period
  • the receiving process monitors the signal in the next receiving period; it should be noted that this embodiment
  • the processor 602 can estimate channel characteristics by using the prior art, and details are not described herein again.
  • the second signal is a first part of the first receiving period, and after demodulation, can be used to indicate the arrival of the data, indicate the format of the data stream, estimate the channel characteristics, estimate the received signal energy intensity, estimate the frequency error, and time.
  • the preamble word of the error or the like may be in the first receiving period simultaneously with the first signal, or may be in the first receiving period before the receiving period of the first signal; when receiving at the first signal.
  • the interference cancellation vector in the interference cancellation matrix for canceling the data stream after demodulation of the first signal is a historically stored interference cancellation vector, instead of the first received according to the current reception period.
  • the processor 602 may use the interference feature vector of the pre-recorded interference signal as the interference feature vector in the interference feature, as follows:
  • the transceiver 601 is further configured to receive a third signal in a second receiving period
  • the processor 602 is specifically configured to determine whether the third signal is an interference signal
  • the third signal is an interference signal, recording an interference feature vector of the third signal on the Nr receiving antennas;
  • the weighted summed result is recorded as an interference feature vector of the third signal on the Nr receive antennas.
  • the second receiving period may be any receiving period before the first receiving period.
  • the processor 602 may determine whether the third signal is an interference signal by using any one of the following (1), (2), and (3):
  • the data frame may be a physical (MAC) layer frame or a higher-level service frame (such as an IP packet); the domain may be an address field of the data frame, for example, the domain of the 802.11 MAC frame may be a destination address or a source address.
  • the IP packet field may be any address included in the IP packet, or may be an identifier for identifying the WLAN, such as: Service Set Identification (SSID), Basic Service Set Identification (abbreviation) BSSID) and so on.
  • SSID Service Set Identification
  • BSSID Basic Service Set Identification
  • the third signal is demodulated into a MAC frame, and the destination address is A1, it is determined that the third signal is an interference signal.
  • the third signal is an interference signal.
  • the data stream information is information necessary for demodulating the signal to obtain the data stream, including: Modulation and Coding Scheme (MCS), channel bandwidth, and space-time block coding (STBC) technology. Use, Forward Error Correction (FEC) coding method, etc.
  • MCS Modulation and Coding Scheme
  • STBC space-time block coding
  • FEC Forward Error Correction
  • the receiving device may also select N from the pre-stored interference feature set.
  • the interference feature vector corresponding to different interference sources is used as the interference feature, wherein the interference feature set records interference feature vectors corresponding to multiple types of interference sources, and the interference feature vector corresponding to each type of interference source may be based on the interference signal recorded multiple times.
  • the interference eigenvector is obtained, for example:
  • the preset threshold value is used to record the at least one recorded interference feature vector as the interference feature vector corresponding to the first type of interference source.
  • the preset threshold value may be set as needed, and the comparison in the embodiment of the present invention is not limited; the calculation of the correlation degree may adopt the prior art, and details are not described herein again.
  • the interference feature set may further include: an occupied channel time or a signal energy corresponding to each type of interference source; optionally, the receiving device may further select an interference feature vector corresponding to the N different interference sources from the pre-stored interference feature set.
  • the interference feature the details are as follows:
  • the receiving device selects, as the interference feature, an interference feature vector corresponding to N different interference sources occupying the longest channel time or the highest signal energy from the pre-stored interference feature set.
  • the processor 602 may be configured according to the channel feature and the interference feature according to any one of (a) orthogonal method, (b) matrix inversion, and (c) ⁇ matrix decomposition described below.
  • the interference cancellation matrix :
  • the processor 602 may calculate one or more interference cancellation vectors by using an orthogonal method, and combine the interference cancellation vectors into an interference cancellation matrix, as follows:
  • the vertical direction of the phase may be approximately 90 degrees vertical or completely 90 degrees vertical (ideal state); the preset angle may be set as needed, and details are not described herein again.
  • the processor 602 is specifically configured to:
  • M vectors corresponding to the channel features in the inverse matrix or M linearly combined vectors corresponding to the channel features are combined into the interference cancellation matrix.
  • the M vectors corresponding to the channel feature may be: a vector in which the column (row) number sequence number is equal to the number of rows (columns) in which the channel feature corresponding to the data stream that needs to cancel the interference in the channel feature is equal; For example, if the number of data streams that need to cancel the interference is M, and the data stream in the channel matrix that needs to cancel the interference corresponds to the second column and the third column of the first joint matrix, then the second row and the third row in the inverse matrix The vector combination of the rows forms an interference cancellation matrix.
  • the linear combination may be a multiplication of a vector included in the channel matrix by a coefficient, and the coefficient is a scaling factor, and the amplitude of the vector may be adjusted to a certain range to avoid introducing an excessively large fixed-point error.
  • the matrix inversion operation may be performed on the first joint matrix. inverse.
  • the processor 602 may perform multiple approximate inversions on the first joint matrix, and select a pre-M row vector that satisfies the requirement as a
  • the interference cancellation matrix is as follows:
  • the M vectors corresponding to the maximum signal to noise ratio or the M linear combined vectors corresponding to the maximum signal to noise ratio are combined into the interference cancellation matrix.
  • the interference feature may be added to the column behind the joint channel matrix, or may be added to the column in front of the joint channel matrix;
  • (H1i, H2i, ..., HNri) is the channel corresponding to the i-th data stream.
  • the characteristics, (IC1i, IC2i, ..., ICNri) are the i-th interference characteristics to be interfered with.
  • the first M row vector in the inverse matrix H' -1 is taken as the interference cancellation matrix C to cancel the interference in the M data streams, or the inverse matrix H' -1
  • the pre-M line vector is multiplied by the coefficient D as the interference cancellation matrix C:
  • D is a diagonal matrix, which is a scaling factor that adjusts the amplitude of C to a certain range to avoid introducing excessive fixed-point errors.
  • H ' is the number of rows of the matrix, is not equal to the number of columns, or H' matrix of full rank, it is possible to find the pseudo-inverse H 'L.
  • the H' -1 is subjected to multiple approximate inversions, and a interference cancellation matrix that satisfies the requirements is selected, as follows:
  • the interference cancellation matrix corresponding to the maximum signal to noise ratio is used as the interference cancellation matrix C.
  • the signal to noise ratio SNR of the signal can be calculated according to the following formula:
  • diag indicates that the matrix is diagonal, x is the transmitted signal, diag(C ⁇ H) ⁇ x is the useful signal after canceling the interference, and non-diag(C ⁇ H) ⁇ x is the interference between the useful signals;
  • sumByRow means summation by row, sumByRow(C ⁇ IC+C ⁇ BNG) is the interference of interference source and noise, and BNG is the background noise amplitude received by each antenna in the system.
  • the processor 602 is configured to combine the channel feature estimated by the processor 602 with the interference feature acquired by the processor 602 into a second joint matrix H';
  • the transceiver 601 is configured to send, to the sending device, the V matrix decomposed by the processor 602, so that the sending device sets the precoding coefficient according to the V matrix.
  • the processor 602 is specifically configured to:
  • a matrix conjugate of the U matrix combined with the M vectors corresponding to the channel feature is transposed as the interference cancellation matrix.
  • the M vectors corresponding to the channel feature may be: a vector in which the column (row) number sequence number is equal to the number of rows (columns) in which the channel feature corresponding to the data stream that needs to cancel the interference in the channel feature is equal;
  • ⁇ matrix decomposition can be singular value decomposition Any of the decomposition methods such as (SVD) and geometric mean decomposition (GMD).
  • the interference feature may be added to the column behind the joint channel matrix, or may be added to the column in front of the joint channel matrix;
  • (H1i, H2i, ..., HNri) is the channel corresponding to the i-th data stream.
  • the characteristics, (IC1i, IC2i, ..., ICNri) are the i-th interference characteristics to be interfered with.
  • H' U ⁇ S ⁇ V
  • the U and the V are a unitary matrix
  • the S is a diagonal matrix
  • the matrix conjugate composed of the M-column M-column vectors is transposed as the interference cancellation matrix.
  • the receiving device can utilize the obtained interference cancellation matrix to cancel the interference in the multiple data streams and provide the reliability of the data transmission.
  • the processor 602 is further configured to:
  • the processor 602 multiplies the interference cancellation matrix by the first signal, calculating each row vector of each interference feature vector of the interference matrix and a channel characteristic of a channel transmitting the first signal or The relevance of the column vector;
  • the processor 602 is specifically configured to:
  • the interference cancellation matrix and the first Multiply a signal If it is determined to be less than the second preset threshold, the interference cancellation matrix and the first Multiply a signal.
  • the second preset threshold may be set as needed.
  • the comparison in the embodiment of the present invention is not limited. If the correlation is less than the second preset threshold, the interference feature of the interference source is not related to the channel matrix. Using the interference cancellation vector to cancel the interference in the signal without significantly weakening the strength of the useful signal;
  • the correlation is greater than or equal to the second preset threshold, it indicates that the interference characteristic of the interference source is related to the channel matrix, and the interference of the interference cancellation vector cancels the signal, and the intensity of the useful signal in the signal is also weakened. Multiplying the first signal by the interference cancellation matrix.
  • a clear channel assessment (CCA) is required for the channel of the transmitted signal, and if the channel is a busy channel, the received first partial signal is performed.
  • CCA clear channel assessment
  • the receiving device may mistake the channel for busy, in order to avoid The receiving device misinterprets the channel occupied by the interference as a busy channel that the transmitting device is transmitting a signal.
  • the processor 602 is further configured to:
  • the second signal is received by using a pre-stored first interference cancellation vector to cancel the interference in the second signal.
  • the processor 602 is specifically configured to:
  • the third preset threshold is greater than or equal to, determining that the channel is busy, and estimating, according to the second signal, a channel characteristic of the second signal;
  • the channel may be used to transmit data to the transmitting device.
  • the embodiment of the present invention provides a receiving device, after receiving the first signal, multiplying the obtained interference cancellation matrix by the first signal, and demodulating the multiplied signal to obtain M data streams.
  • the data obtained after demodulation is used to cancel the interference data, which greatly improves the reliability of data transmission.
  • the disclosed system, apparatus, and method may be implemented in other manners.
  • the device embodiments described above are merely illustrative.
  • the division of the unit is only a logical function division.
  • there may be another division manner for example, multiple units or components may be combined or Can be integrated into another system, or some features can be ignored or not executed.
  • the mutual coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection through some interface, device or unit, and may be electrical or otherwise.
  • the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, may be located in one place, or may be distributed to multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of the embodiment.
  • each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may be physically included separately, or two or more units may be integrated into one unit.
  • the above integrated unit can be implemented in the form of hardware or in the form of hardware plus software functional units.
  • the above-described integrated unit implemented in the form of a software functional unit can be stored in a computer readable storage medium.
  • the above software functional unit is stored in a storage medium and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to perform the methods of the various embodiments of the present invention. Part of the steps.
  • the foregoing storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk, and the like, and the program code can be stored. Medium.

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Abstract

本发明实施例公开了一种干扰抵消方法及设备,涉及通信技术领域,以抵消接收设备接收到的数据中的干扰,提高数据传输的可靠性。本发明实施例提供的方法包括:接收第一信号;获取干扰抵消矩阵;所述干扰抵消矩阵包含M个干扰抵消向量,每个干扰抵消向量包含Nr个干扰抵消系数,所述每个干扰抵消向量与N个干扰源中任一个干扰源在Nr个接收天线上的干扰特征向量的相关度小于第一预设阈值;所述M为预先设置的干扰抵消向量的个数;所述N为预先设置的干扰的个数;将所述干扰抵消矩阵与所述第一信号相乘,并将相乘后的信号解调获得数据流。

Description

一种干扰抵消方法及设备 技术领域
本发明涉及通信技术领域,尤其涉及一种干扰抵消方法及设备。
背景技术
随着通信技术的发展,无线局域网(Wireless Local Area Network,简称WLAN)的应用已经越来越广泛。WLAN是以各种无线电波(如激光、红外线、无线射频等)的无线信道来代替有线局域网中的部分或全部传输介质所构成的网络。WLAN包括无线保真(WIreless-FIdelity,简称Wi-Fi)、蓝牙(Bluetooth),Zigbee,授权频段辅助接入(Licensed-Assisted Access,简称LAA)等无线传输技术,均利用高频无线射频作为传输介质。
由于高频无线射频频段的各个频段,承载了各种无线应用,包括Wi-Fi,雷达,蓝牙,Zigbee,LAA等等,不同的协议间相互影响和干扰,因此,在WLAN系统中,即使同一种Wi-Fi协议,不同的无线访问接入点(Wireless Access Point,简称AP)间的数据也会相互影响,另外,一些家用电器,例如微波炉、玩具遥控器、母婴监控设备也会产生高频干扰。为了避免干扰所带来的不良影响,在WLAN系统中,通常采用载波侦听多路访问/冲突避免(Carrier Sense Multiple Access with Collision Avoidance,简称CSMA/CA)机制,避免多个用户同时发送数据发生冲突而产生的干扰。
在CSMA/CA中,每个站点在开始传送数据前,首先侦听信道是否空闲,若侦听到信道空闲,站点开始等待一个随机退避时段,在此期间其继续进行信道侦听,若直到等待时段结束时信道仍为空闲,则站点开始传送;若侦听到信道忙,则站点必须延迟至当前传输结束后,再任选一个随机退避时段,并在这段时间内继续侦听,若直到等待时段结束时信道仍为空闲,则站点开始传送。这样, CAMA/CA机制可以避免在干扰出现的时候发送数据,以避免发送内容被干扰“污染”。
虽然,CSMA/CA机制对干扰所产生的影响有一定的缓解作用,但也存在如下缺陷:若干扰发生在发送数据开始之后,发送数据结束之前,退避机制会失效,对于接收设备而言接收到的数据仍旧会被干扰破坏,降低了数据传输的可靠性。
发明内容
本发明提供一种干扰抵消方法及设备,以抵消接收设备接收到的数据中的干扰,提高数据传输的可靠性。
为达到上述目的,本发明的实施例采用如下技术方案:
第一方面,本发明实施例提供一种干扰抵消方法,应用于接收设备,其中,所述接收设备配置有Nr个接收天线,用于接收Nt个发送天线或空间流或空间时间流输出的信号,所述Nr为大于等于2的整数,所述Nt为大于等于1的整数;所述方法包括:
接收第一信号;其中,所述第一信号包含Nr个接收天线接收到的Nt个发送天线或空间流或空间时间流输出的信号经过信道后的信号和噪声信号;
获取干扰抵消矩阵;所述干扰抵消矩阵包含M个干扰抵消向量,每个干扰抵消向量包含Nr个干扰抵消系数,所述每个干扰抵消向量与N个干扰源中任一个干扰源在Nr个接收天线上的干扰特征向量的相关度小于第一预设阈值;所述M为预先设置的干扰抵消向量的个数;所述N为预先设置的干扰的个数;
将所述干扰抵消矩阵与所述第一信号相乘,并将相乘后的信号解调获得数据流。
在第一方面的第一种可实现方式中,结合第一方面,所述获取干扰抵消矩阵包括:
在第一接收周期内接收第二信号,其中,所述第二信号为Nr个接收天线接收到的信号;
根据所述第二信号估计传输所述第二信号的信道的信道特 征;其中,所述信道特征为Nr乘Nt的矩阵;
获取干扰特征,其中,所述干扰特征由N个向量组成,第i个向量为第i个干扰源在所述Nr个接收天线上的干扰特征向量;
根据所述信道特征和所述干扰特征获取所述干扰抵消矩阵。
在第一方面的第二种可实现方式中,结合第一方面的第一种可实现方式,对于所述干扰抵消矩阵中的任一干扰抵消向量,所述根据所述信道特征和所述干扰特征获取干扰抵消向量包括:
获取与所述干扰特征中干扰特征向量相垂直的、且与所述信道特征夹角最小的一个或与所述信道特征夹角小于预设角度的特征向量作为所述干扰抵消向量。
在第一方面的第三种可实现方式中,结合第一方面的第一种可实现方式,所述根据所述信道特征和所述干扰特征获取干扰抵消矩阵包括:
将所述信道特征与所述干扰特征组合成第一联合矩阵;
对所述第一联合矩阵进行矩阵求逆运算,获得逆矩阵;
将所述逆矩阵中与所述信道特征对应的M个向量或将与所述信道特征对应的M个线性组合后的向量组合成所述干扰抵消矩阵。
在第一方面的第四种可实现方式中,结合第一方面的第三种可实现方式,对所述第一联合矩阵进行矩阵求逆运算,获得逆矩阵包括:
对所述第一联合矩阵进行至少一次近似求逆,获得至少一个近似逆矩阵;
所述将所述逆矩阵中与所述信道特征对应的M个向量或将与所述信道特征对应的M个线性组合后的向量组合成所述干扰抵消矩阵包括:
分别利用所述至少一个近似逆矩阵中与所述信道特征对应的M个向量计算所述第一信号的信噪比,获得至少一个信噪比;
将所述至少一个信噪比中,最大信噪比对应的M个向量或者 将最大信噪比对应的M个线性组合后向量组合成所述干扰抵消矩阵。
在第一方面的第五种可实现方式中,结合第一方面的第一种可实现方式,在根据所述信道特征和所述干扰特征获取干扰抵消矩阵之前,所述方法还包括:
将所述信道特征与所述干扰特征组合成第二联合矩阵H′;
对所述第二联合矩阵进行酉矩阵分解,获得H′=U×S×V;其中,所述U和所述V为一个酉矩阵,所述S为一个对角矩阵;
向发送设备发送所述V矩阵,以使得所述发送设备根据所述V矩阵设置预编码系数。
在第一方面的第六种可实现方式中,结合第一方面的第五种可实现方式,所述根据所述信道特征和所述干扰特征获取干扰抵消矩阵包括:
将所述U矩阵中与所述信道特征对应的M个向量组成的矩阵共轭转置后作为所述干扰抵消矩阵。
在第一方面的第七种可实现方式中,结合第一方面的第一种可实现方式至第一方面的第六种可实现方式中的任一种可实现方式,对于所述干扰特征中的任一个干扰特征向量,在所述获取所述干扰特征向量之前,所述方法还包括:
在第二接收周期内接收第三信号;
若确定所述第三信号为干扰信号,则记录所述第三信号在Nr个接收天线上的干扰特征向量;
所述获取所述干扰特征向量包括:
将所述第三信号在Nr个接收天线上的干扰特征向量作为所述干扰特征向量;或
所述获取所述干扰特征向量包括:
对所述第三信号在Nr个接收天线上的干扰特征向量与其他至少一个接收周期接收到的干扰信号在Nr个接收天线上的干扰特征向量进行加权求和;
将加权求和后的结果记录为所述第三信号在Nr个接收天线上的干扰特征向量。
在第一方面的第八种可实现方式中,结合第一方面的第七种可实现方式,所述确定所述第三信号为干扰信号包括:
对所述第三信号进行解调,若解调出的数据帧的至少一个域与预设干扰源的域相同,则确定所述第三信号为干扰信号。
在第一方面的第九种可实现方式中,结合第一方面的第七种可实现方式,所述确定所述第三信号为干扰信号包括:
解调所述第三信号对应的域消息SIG;其中,所述SIG包括:数据流信息和校验字段;
根据预设算法计算第一校验字段,若所述第一校验字段与所述SIG中包含的校验字段不同,则确定所述第三信号为干扰信号;
或者,若所述数据流信息的数据格式与预设数据格式不同,则确定所述第三信号为干扰信号。
在第一方面的第十种可实现方式中,结合第一方面的第一种可实现方式至第一方面的第九种可实现方式中的任一种可实现方式,在将所述干扰抵消矩阵与所述第一信号相乘之前,所述方法还包括:
计算所述干扰矩阵中每个干扰特征向量与传输所述第一信号的信道的信道特征的每一行向量或列向量的相关度;
确定所述干扰矩阵的每个干扰特征向量与传输所述第一信号的信道的信道特征的每一行向量或列向量的相关度是否小于第二预设阈值;
所述将所述干扰抵消矩阵与所述第一信号相乘具体包括:
若确定小于第二预设阈值,则将所述干扰抵消矩阵与所述第一信号相乘。
在第一方面的第十一种可实现方式中,结合第一方面的第十种可实现方式,在根据所述第二信号估计发送所述第二信号的信道特征之前,所述方法还包括:
用预先存储的第一干扰抵消向量接收所述第二信号,以抵消所述第二信号中的干扰;
确定接收到的所述第二信号的信号能量是否大于等于第三预设阈值;
所述根据所述第二信号估计发送所述第二信号的信道特征具体包括:
若大于等于所述第三预设阈值,则根据所述第二信号估计发送所述第二信号的信道特征。
第二方面,本发明实施例提供一种接收设备,所述接收设备配置有Nr个接收天线,用于接收Nt个发送天线或空间流或空间时间流输出的信号,所述Nr为大于等于2的整数;所述Nt为大于等于1的整数;包括:
接收单元,用于接收第一信号;其中,所述第一信号包含Nr个接收天线接收到的Nt个发送天线或空间流或空间时间流输出的信号经过信道后的信号和噪声信号;
获取单元,用于获取干扰抵消矩阵;所述干扰抵消矩阵包含M个干扰抵消向量,每个干扰抵消向量包含Nr个干扰抵消系数,所述每个干扰抵消向量与N个干扰源中任一个干扰源在Nr个接收天线上的干扰特征向量的相关度小于第一预设阈值;所述M为预先设置的干扰抵消向量的个数;所述N为预先设置的干扰的个数;
干扰抵消单元,用于将所述干扰抵消矩阵与所述第一信号相乘,并将相乘后的信号解调获得数据流。
在第二方面的第一种可实现方式中,结合第二方面,所述接收单元,还用于在第一接收周期内接收第二信号,其中,所述第二信号为Nr个接收天线接收到的信号;
所述接收设备还包括:
信道估计单元,用于根据所述接收单元接收到的第二信号估计传输所述第二信号的信道的信道特征;其中,所述信道特征为Nr乘Nt的矩阵;
所述获取单元,具体用于:
获取干扰特征,其中,所述干扰特征由N个向量组成,第i个向量为第i个干扰源在所述Nr个接收天线上的干扰特征向量;
并根据所述信道估计单元估计出的信道特征和获取到的所述干扰特征获取干扰抵消矩阵。
在第二方面的第二种可实现方式中,结合第二方面的第一种可实现方式,对于所述干扰抵消矩阵中的任一干扰抵消向量,所述获取单元,具体用于:
获取与所述干扰特征中干扰特征向量相垂直的、且与所述信道特征夹角最小的一个或与所述信道特征夹角小于预设角度的特征向量作为所述干扰抵消向量。
在第二方面的第三种可实现方式中,结合第二方面的第一种可实现方式,所述获取单元,具体用于:
将所述信道特征与所述干扰特征组合成第一联合矩阵;
对所述第一联合矩阵进行矩阵求逆运算,获得逆矩阵;
将所述逆矩阵中与所述信道特征对应的M个向量或将与所述信道特征对应的M个线性组合后的向量组合成所述干扰抵消矩阵。
在第二方面的第四种可实现方式中,结合第二方面的第三种可实现方式,所述获取单元,具体用于:
对所述第一联合矩阵进行至少一次近似求逆,获得至少一个近似逆矩阵;
分别利用所述至少一个近似逆矩阵中与所述信道特征对应的M个向量计算所述第一信号的信噪比,获得至少一个信噪比;
将所述至少一个信噪比中,最大信噪比对应的M个向量或者将最大信噪比对应的M个线性组合后向量组合成所述干扰抵消矩阵。
在第二方面的第五种可实现方式中,结合第二方面的第一种可实现方式,所述接收设备还包括:
分解单元,用于在所述获取单元根据所述信道特征和所述干扰特征获取干扰抵消矩阵之前,将所述信道估计单元估计出的信道特征与所述获取单元获取到的干扰特征组合成第二联合矩阵H′;
对所述第二联合矩阵进行酉矩阵分解,获得H′=U×S×V;其中,所述U和所述V为一个酉矩阵,所述S为一个对角矩阵;
发送单元,用于向发送设备发送所述分解单元分解出的V矩阵,以使得所述发送设备根据所述V矩阵设置预编码系数。
在第二方面的第六种可实现方式中,结合第二方面的第五种可实现方式,所述获取单元,具体用于:
将所述U矩阵中与所述信道特征对应的M个向量组成的矩阵共轭转置后作为所述干扰抵消矩阵。
在第二方面的第七种可实现方式中,结合第二方面的第一种可实现方式至第二方面的第六种可实现方式中的任一种可实现方式,对于所述干扰特征中的任一个干扰特征向量,在所述获取单元获取所述干扰特征向量之前,
所述接收单元,还用于在第二接收周期内接收第三信号;
所述获取单元,还用于若确定所述接收单元接收到的所述第三信号为干扰信号,则记录所述第三信号在Nr个接收天线上的干扰特征向量;
将所述第三信号在Nr个接收天线上的干扰特征向量作为所述干扰特征;或
对所述第三信号在Nr个接收天线上的干扰特征向量与其他至少一个接收周期接收到的干扰信号在Nr个接收天线上的干扰特征向量进行加权求和;
将加权求和后的结果记录为所述第三信号在Nr个接收天线上的干扰特征向量。
在第二方面的第八种可实现方式中,结合第二方面的第七种可实现方式,所述获取单元,具体用于:
对所述第三信号进行解调,若解调出的数据帧的至少一个域 与预设干扰源的域相同,则确定所述第三信号为干扰信号。
在第二方面的第九种可实现方式中,结合第二方面的第七种可实现方式,所述获取单元,具体用于:
解调所述第三信号对应的域消息SIG;其中,所述SIG包括:数据流信息和校验字段;
根据预设算法计算第一校验字段,若所述第一校验字段与所述SIG中包含的校验字段不同,则确定所述第三信号为干扰信号;
或者,若所述数据流信息的数据格式与预设数据格式不同,则确定所述第三信号为干扰信号。
在第二方面的第十种可实现方式中,结合第二方面的第一种可实现方式至第二方面的第九种可实现方式中的任一种可实现方式,所述接收设备还包括:
计算单元,用于在所述干扰抵消单元将所述干扰抵消矩阵与所述第一信号相乘之前,计算所述干扰矩阵中每个干扰特征向量与传输所述第一信号的信道的信道特征的每一行向量或列向量的相关度;
确定所述干扰矩阵的每个干扰特征向量与传输所述第一信号的信道的信道特征的每一行向量或列向量的相关度是否小于第二预设阈值;
所述干扰抵消单元,具体用于:
若确定小于第二预设阈值,则将所述干扰抵消矩阵与所述第一信号相乘。
在第二方面的第十一种可实现方式中,结合第二方面的第十种可实现方式,所述干扰抵消单元,还用于:
在所述信道估计单元根据所述第二信号估计发送所述第二信号的信道特征之前,用预先存储的第一干扰抵消向量接收所述第二信号,以抵消所述第二信号中的干扰;
确定接收到的所述第二信号的信号能量是否大于等于第三预设阈值;
所述信道估计单元,具体用于:
若大于等于所述第三预设阈值,则根据所述第二信号估计发送所述第二信号的信道特征。
第三方面,本发明实施例提供一种接收设备,所述接收设备配置有Nr个接收天线,用于接收Nt个发送天线或空间流或空间时间流输出的信号,所述Nt为大于等于2的整数,所述Nt为大于等于1的整数;包括:
收发器,用于接收第一信号;其中,所述第一信号包含Nr个接收天线接收到的Nt个发送天线或空间流或空间时间流输出的信号经过信道后的信号和噪声信号;
处理器,用于获取干扰抵消矩阵;所述干扰抵消矩阵包含M个干扰抵消向量,每个干扰抵消向量包含Nr个干扰抵消系数,所述每个干扰抵消向量与N个干扰源中任一个干扰源在Nr个接收天线上的干扰特征向量的相关度小于第一预设阈值;所述M为预先设置的干扰抵消向量的个数;所述N为预先设置的干扰的个数;
干扰抵消单元,用于将所述干扰抵消矩阵与所述第一信号相乘,并将相乘后的信号解调获得数据流。
在第三方面的第一种可实现方式中,结合第三方面,所述收发器,还用于在第一接收周期内接收第二信号,其中,所述第二信号为Nr个接收天线接收到的信号;
所述处理器,具体用于:
根据所述收发器接收到的第二信号估计传输所述第二信号的信道的信道特征;其中,所述信道特征为Nr乘Nt的矩阵;
获取干扰特征,其中,所述干扰特征由N个向量组成,第i个向量为第i个干扰源在所述Nr个接收天线上的干扰特征向量;
并根据所述处理器估计出的信道特征和获取到的所述干扰特征获取干扰抵消矩阵。
在第三方面的第二种可实现方式中,结合第三方面的第一种可实现方式,对于所述干扰抵消矩阵中的任一干扰抵消向量,所述 处理器,具体用于:
获取与所述干扰特征中干扰特征向量相垂直的、且与所述信道特征夹角最小的一个或与所述信道特征夹角小于预设角度的特征向量作为所述干扰抵消向量。
在第三方面的第三种可实现方式中,结合第三方面的第一种可实现方式,所述处理器,具体用于:
将所述信道特征与所述干扰特征组合成第一联合矩阵;
对所述第一联合矩阵进行矩阵求逆运算,获得逆矩阵;
将所述逆矩阵中与所述信道特征对应的M个向量或将与所述信道特征对应的M个线性组合后的向量组合成所述干扰抵消矩阵。
在第三方面的第四种可实现方式中,结合第三方面的第三种可实现方式,所述处理器,具体用于:
对所述第一联合矩阵进行至少一次近似求逆,获得至少一个近似逆矩阵;
分别利用所述至少一个近似逆矩阵中与所述信道特征对应的M个向量计算所述第一信号的信噪比,获得至少一个信噪比;
将所述至少一个信噪比中,最大信噪比对应的M个向量或者将最大信噪比对应的M个线性组合后向量组合成所述干扰抵消矩阵。
在第三方面的第五种可实现方式中,结合第三方面的第一种可实现方式,所述处理器,还用于:
在所述处理器根据所述信道特征和所述干扰特征获取干扰抵消矩阵之前,将所述处理器估计出的信道特征与所述处理器获取到的干扰特征组合成第二联合矩阵H′;
对所述第二联合矩阵进行酉矩阵分解,获得H′=U×S×V;其中,所述U和所述V为一个酉矩阵,所述S为一个对角矩阵;
所述收发器,还用于向发送设备发送所述处理器分解出的V矩阵,以使得所述发送设备根据所述V矩阵设置预编码系数。
在第三方面的第六种可实现方式中,结合第三方面的第五种可实现方式,所述处理器,具体用于:
将所述U矩阵中与所述信道特征对应的M个向量组成的矩阵共轭转置后作为所述干扰抵消矩阵。
在第三方面的第七种可实现方式中,结合第三方面的第一种可实现方式至第三方面的第六种可实现方式中的任一种可实现方式,对于所述干扰特征中的任一个干扰特征向量,在所述处理器获取所述干扰特征向量之前,
所述收发器,还用于在第二接收周期内接收第三信号;
所述处理器,还用于若确定所述收发器接收到的所述第三信号为干扰信号,则记录所述第三信号在Nr个接收天线上的干扰特征向量;
将所述第三信号在Nr个接收天线上的干扰特征向量作为所述干扰特征;或
对所述第三信号在Nr个接收天线上的干扰特征向量与其他至少一个接收周期接收到的干扰信号在Nr个接收天线上的干扰特征向量进行加权求和;
将加权求和后的结果记录为所述第三信号在Nr个接收天线上的干扰特征向量。
在第三方面的第八种可实现方式中,结合第三方面的第七种可实现方式,所述处理器,具体用于:
对所述第三信号进行解调,若解调出的数据帧的至少一个域与预设干扰源的域相同,则确定所述第三信号为干扰信号。
在第三方面的第九种可实现方式中,结合第三方面的第七种可实现方式,所述处理器,具体用于:
解调所述第三信号对应的域消息SIG;其中,所述SIG包括:数据流信息和校验字段;
根据预设算法计算第一校验字段,若所述第一校验字段与所述SIG中包含的校验字段不同,则确定所述第三信号为干扰信号;
或者,若所述数据流信息的数据格式与预设数据格式不同,则确定所述第三信号为干扰信号。
在第三方面的第十种可实现方式中,结合第三方面的第一种可实现方式至第三方面的第九种可实现方式中的任一种可实现方式,
所述处理器,还用于在所述处理器将所述干扰抵消矩阵与所述第一信号相乘之前,计算所述干扰矩阵中每个干扰特征向量与传输所述第一信号的信道的信道特征的每一行向量或列向量的相关度;
确定所述干扰矩阵的每个干扰特征向量与传输所述第一信号的信道的信道特征的每一行向量或列向量的相关度是否小于第二预设阈值;
若确定小于第二预设阈值,则将所述干扰抵消矩阵与所述第一信号相乘。
在第三方面的第十一种可实现方式中,结合第三方面的第十种可实现方式,所述处理器,还用于:
在所述处理器根据所述第二信号估计发送所述第二信号的信道特征之前,用预先存储的第一干扰抵消向量接收所述第二信号,以抵消所述第二信号中的干扰;
确定接收到的所述第二信号的信号能量是否大于等于第三预设阈值;
若大于等于所述第三预设阈值,则根据所述第二信号估计发送所述第二信号的信道特征。
由上可知,本发明实施例提供一种干扰抵消方法及设备,接收到第一信号后,用获取的干扰抵消矩阵与所述第一信号相乘,并将相乘后的信号解调获得M条数据流,以抵消M条数据流中的干扰,使得解调后获得数据为抵消干扰后的数据,大大提高了数据传输的可靠性。
附图说明
为了更清楚地说明本发明实施例或现有技术中的技术方案, 下面将对实施例或现有技术描述中所需要使用的附图作简单地介绍,显而易见地,下面描述中的附图仅仅是本发明的一些实施例,对于本领域普通技术人员来讲,在不付出创造性劳动的前提下,还可以根据这些附图获得其他的附图。
图1为WLAN系统信道模型示意图;
图2为本发明实施例提供的干扰抵消的原理框图;
图2A为本发明实施例提供的另一种干扰抵消的原理框图;
图3为本发明实施例提供的一种干扰抵消方法的流程图;
图4为本发明实施例提供的一接收周期中信号格式示意图;
图5为本发明实施例提供的一种接收设备50的结构图;
图5A为本发明实施例提供的一种接收设备50的结构图;
图5B为本发明实施例提供的一种接收设备50的结构图;
图5C为本发明实施例提供的一种接收设备50的结构图;
图6为本发明实施例提供的一种接收设备60的结构图。
具体实施方式
下面将结合本发明实施例中的附图,对本发明实施例中的技术方案进行清楚、完整地描述,显然,所描述的实施例仅仅是本发明一部分实施例,而不是全部的实施例。基于本发明中的实施例,本领域普通技术人员在没有做出创造性劳动前提下所获得的所有其他实施例,都属于本发明保护的范围。
需要说明的是,本发明实施例提供的干扰抵消方法不仅适用于WLAN系统,还可以适用于其他采用多天线接收技术的通信系统中,本发明对比不进行限定,本发明仅以WLAN系统为例进行说明。
在WLAN系统中,通常情况下,WLAN信道和信道模型如图1所示,当存在多个收发天线时,接收设备和发送设备之间的信号可以通过多个路径传输,在未受到干扰源干扰的情况下,接收设备接收的信号可以表示为:y=H·x+n,然后再对接收到的信号经过解调处理恢复出需要的数据或信息;其中,x是发送设备发送的信 号,可以为一个Nt维向量(x1,x2,…,xNt),其中,Nt可以为发送天线的个数,也可以为发送的空间流(space stream)的个数,还可以为发送的空间时间流(space-time stream)的个数,即x是Nt个天线或空间流或空间时间流输出的信号,xj为第j个发送天线或空间流或空间时间流输出的信号;需要说明的是,在802.11n系列标准中,空间流可以为在多个空间维度上传输的比特(bit)流或调制符号流;空间时间流可以为由一个或多个空间流进行空间组合和临时处理得到的调制符号流;通常情况下,用户数据可以被分为多个Nt个空间流,在大于或等于Nt的发送天线上传输,例如,弱信号被分成2个空间流,然后对2个空间流信号进行空间时间块编码(STBC)处理变成4个空间时间流信号,然后进一步处理成4个发送天线的发送信号,那么发送信号x可以是2个空间流的信号,也可以是4个空间时间流的信号,也可以是4个发送天线发送的信号。
其中,y是接收设备接收到信号,可以为一个Nr维向量(y1,y2,…,yNr),yi为第i个接收天线接收的信号;n为噪声信号;H为信道矩阵(也可称为MIMO信道),为Nr乘Nt的矩阵,可以表示为一个Nr行Nt列的矩阵,也可以为一个Nr列Nt行的矩阵,本发明实施例对比不进行限定,本发明实施例仅以H为如下所示的Nr行Nt列的矩阵为例进行说明,其中,Hij为第j个发送天线或空间流或空间时间流到第i个接收天线之间的信道特征:
Figure PCTCN2015078597-appb-000001
在如图1所示的信道模型中,接收设备遭受的干扰信号可以表示为:Iy=IC·I;其中,I为干扰源发出的干扰信号,可以为一个N维向量(I1,I2,…,IN),N为干扰源的个数,Ij为第j个干扰源的干扰信号;Iy是接收设备遭受的干扰信号之和,可以为一个Nr维向量(Iy1,Iy2,…,IyNr),Iyi为第i个接收天线遭受 的干扰信号之和;IC为干扰特征(也可称为干扰信道),可以表示为N个Nr维的行向量或者列向量组成的矩阵,本发明实施例对此不进行限定,本发明实施例仅以IC为如下所示的N个Nr维的列向量组成的矩阵为例进行说明,其中,第j列向量为第j个干扰源的干扰特征:
Figure PCTCN2015078597-appb-000002
由上可知,当接收设备接收到的信号被干扰时,接收信号可以表示为:y=H·x+IC·I+n;此时,若可以获取一个向量,与IC矩阵每列向量乘积后的结果模值尽可能的趋向于零或等于零(理想状态下),则可以最大程度的减小干扰,基于这种思想,本发明提出一种干扰抵消方法,获得一个干扰抵消矩阵以抵消所述信号中的干扰获得有效的数据流,提高数据流的可靠性。
以如图2所示的IEEE 802.11n系列标准的接收设备获取一条数据流为例,接收设备先经过幅度调整、同相正交(In-phase/Quadrature,简称I/Q)信号检测、快速傅里叶变换(Fast Fourier Transformation,简称FFT)处理接收到频域信号,一个数据流对应的频域信号为(y1,…,yNr),然后利用一个干扰抵消向量对所述信号进行干扰抵消(如图2虚线框内部分所示),再经过解调处理获得有用数据流;同理,当接收设备需要同时获得多个数据流(如图2A所示)时,可以分别利用与每个数据流对应的一个干扰抵消向量与信号向量y相乘进行干扰抵消、获得多个数据流的抵消信号,解调处理获得多个数据流。
需要说明的是,本发明可以对频域信号进行干扰抵消,也可以对时域信号进行干扰抵消,对此不进行限制,本发明仅以对频域信号进行干扰抵消为例进行说明。此外,本发明不仅适用于IEEE 802.11系列标准的接收设备,也可以适用于其他标准(如蓝牙、LAA)的接收设备,不论适用于何种标准的接收设备,其干扰抵消 原理是相同的。下面通过实施例一对本发明提供的干扰抵消方法进行介绍。
实施例一
图3为本发明实施例提供的干扰抵消方法的流程图,应用于接收设备,所述接收设备配置有Nr个接收天线,用于接收Nt个发送天线或空间流(space stream)或空间时间流(space-time stream)输出的信号,所述Nr为大于等于2的整数,所述Nt为大于等于1的整数;所述接收设备可以为工作站设备,如:手机、电脑、智能电视、影视盒子等设备;也可以为接入设备,如:无线路由器、部分数字用户线用户终端设备(Digital Subscriber Line Customer Premise Device,简称DSL CPE)、终端设备(Cable Modem,简称CM)、光网络单元(Optical Network Unit,简称ONU)等设备;如图3所示,所述方法可以包括:
301、接收第一信号;其中,所述第一信号包含Nr个接收天线接收到的Nt个发送天线或空间流或空间时间流输出的信号经过信道后的信号和噪声信号。
通常情况下,在WLAN系统中,接收设备可以在一个接收周期内先后接收到至少2部分信号:第一部分信号和第二部分信号;其中,第一部分信号经解调后可获得相应的包含多种用途的前导码字(也称作协议头),如用来指示数据的到达、指示数据流的格式、估计信道特征、估算接收信号能量强度、估计频率误差和时间误差等;第二部分信号可以通过不同的解调方式解调后获得多条数据流。
例如,图4示出了802.11n系列标准中一个接收周期内的信号接收格式,如图4所示,该信号可以包括:第一部分信号和第二部分信号;其中,所述第一部分信号经解调后可对应获得:短训练域(Short Training field,检测STF)、域消息(Signal Field,简称SIG)以及长训练域(Long Training field,简称LTF)信息,STF可用来进行空闲信道评估(Clear Channel Assesement,简称CCA)检测 接收信号到达,SIG可用于判断信号是否为干扰信号,LTF可用来估计信道特征;第二部分信号解调后可对应获得数据(Data)。
可选的,第一信号可以为任一接收周期内的第二部分信号,可被解调出多条数据流,可以未被干扰源干扰,也可以被干扰源所干扰;当第一信号未被干扰源干扰时,第一信号仅包含Nr个接收天线接收到的Nt个发送天线或空间流或空间时间流输出的信号经过信道后的信号和噪声信号,可以表示为:y=H·x+n;当所述第一信号被干扰源所干扰时,第一信号还可以包含干扰信号的合成信号,可以采用图1所示信道模型下的被干扰源干扰的信号表示方式表示:y=H·x+IC·I+n,在此不再赘述。
302、获取干扰抵消矩阵;所述干扰抵消矩阵包含M个干扰抵消向量,每个干扰抵消向量包含Nr个干扰抵消系数,所述每个干扰抵消向量与N个干扰源中任一个干扰源在Nr个接收天线上的干扰特征向量的相关度小于第一预设阈值;所述M为预先设置的干扰抵消向量的个数;所述N为预先设置的干扰的个数。
其中,M可以根据需要进行设置,可以为1个或多个,当M=1时,步骤302中的干扰抵消矩阵仅包含1个干扰抵消向量,即该干扰抵消矩阵可以认为是一个干扰抵消向量;其中,干扰源的个数N可以根据对接收设备所处环境下干扰情况的统计测量获得,可以为一个干扰源,也可以为多个干扰源,本发明实施例对此不进行限制。
其中,本发明实施例中,向量之间的相关度可以指:向量之间的夹角大小,可以用向量夹角的余弦值或者向量夹角余弦值的绝对值表示;若相关度接近0度或180度,则表示向量之间接近平行,向量之间相关;若相关度接近90度,则表示向量之间接近垂直,向量之间不相关;通常情况下,可以采用余弦相关性、皮尔逊积矩(Pearson)相关系数等常用的计算方法获得向量之间的相关度。
所述第一预设阈值可以根据需要设置为尽可能的趋向于零或等于零(理想状态下),所述干扰抵消向量与所述干扰特征中每列干扰特征向量相关度小于第一预设阈值表示:干扰抵消向量与每个 干扰源对应的干扰特征不相关,可以用该干扰抵消向量最大程度的抵消所述干扰源的干扰;所述干扰抵消向量与所述干扰特征中每列干扰特征向量相关度大于等于第一预设阈值表示:干扰抵消向量与每个干扰源对应的干扰特征之间有一定的关联性,不能用该干扰抵消向量抵消所述干扰源的干扰。
可选的,本发明实施例中,接收设备可以通过下述方法获取干扰抵消矩阵:
在第一接收周期内接收第二信号,其中,所述第二信号为Nr个接收天线接收到的信号;
根据所述第二信号估计传输所述第二信号的信道的信道特征;其中,所述信道特征为Nr乘Nt的矩阵;
获取干扰特征,其中,所述干扰特征由N个向量组成,第i个向量为第i个干扰源在所述Nr个接收天线上的干扰特征向量;
根据所述信道特征和所述干扰特征获取所述干扰抵消矩阵。
其中,第二信号为第一接收周期中的第一部分信号,经解调后可获得用于指示数据的到达、指示数据流的格式、估计信道特征、估算接收信号能量强度、估计频率误差和时间误差等的前导码字,可以与第一信号同时处于第一接收周期内,也可以处于所述第一信号所处接收周期之前的第一接收周期内;当处于所述第一信号所处接收周期之前的第一接收周期时,所述干扰抵消矩阵中用于抵消第一信号解调后的数据流的干扰抵消向量为历史存储的干扰抵消向量,而不是根据本次接收周期接收到的第一部分信号估计出的信道矩阵获得的干扰抵消向量。
可选的,在接收到第二信号之后,还需要根据解调后的第二信号判断第二信号是否为有用信号,若所述第二信号为有用信号,再根据传输所述第二信号的信道的信道特征,根据所述信道特征和获取到的干扰特征获取所述干扰抵消矩阵;若第二信号为干扰信号,则记录所述第二信号的干扰特征,结束第一接收周期内后续的接收过程,监测下一接收周期中的信号;需要说明的是,本实施例 所述的有用信号为被干扰源干扰的信号,可以包含发送端发送的信号和干扰信号,如有用信号y=H·x+IC·I+n;而干扰信号为不包含发送端发送的信号,仅被干扰源干扰的信号,如干扰信号:y=IC·I。
303、将所述干扰抵消矩阵与所述第一信号相乘,并将相乘后的信号解调获得数据流。
示例性的,步骤302中信道特征的估计可以采用现有技术,在此不再赘述。
示例性的,对于干扰特征中的任一个干扰特征向量,接收设备可以将预先记录的干扰信号的干扰特征向量作为干扰特征中的干扰特征向量,然后将记录的N个干扰特征向量组合成干扰特征,例如:
接收设备在第二接收周期内接收第三信号,判断所述第三信号是否为干扰信号;
若确定所述第三信号为干扰信号,则记录所述第三信号在Nr个接收天线上的干扰特征向量;
将所述第三信号在Nr个接收天线上的干扰特征向量作为所述干扰特征向量;或者
对所述第三信号在Nr个接收天线上的干扰特征向量与其他至少一个接收周期接收到的干扰信号在Nr个接收天线上的干扰特征向量进行加权求和;
将加权求和后的结果记录为所述第三信号在Nr个接收天线上的干扰特征向量。
其中,所述第二接收周期可以为所述第一接收周期之前的任一接收周期。
具体的,本发明实施例中,可以通过下述(1)(2)(3)中的任一种方式判断所述第三信号是否为干扰信号:
(1)对所述第三信号进行解调,若解调出的数据帧的至少一个域与预设干扰源的域相同,则确定所述第三信号为干扰信号。
其中,数据帧可以为物理(MAC)层帧或更高层业务的帧(如IP包)等;所述域可以为数据帧的地址域,如:802.11MAC帧的域可以为目的地址、源地址,IP包的域可以为IP包包含的任何一个地址;也可以是用于标识WLAN的标识,如:业务集标识(Service Set Identification,简称SSID)、基本业务集标识(Basic Service Set Identification,简称BSSID)等。
例如,若预设干扰源的域为A1,第三信号解调后为MAC帧,且目的地址为A1,则确定第三信号为干扰信号。
(2)解调第三信号对应的域消息SIG;其中,所述第SIG包括:数据流信息和校验字段;
根据预设算法计算第一校验字段,若所述第一校验字段与所述SIG中包含的校验字段不同,则确定所述第三信号为干扰信号;
或者,若所述数据流信息的数据格式与预设数据格式不同,则确定所述第三信号为干扰信号。
其中,数据流信息是解调信号获得数据流所必要的信息,包括:调制和编码方案(Modulation andCoding Scheme,简称MCS)、信道带宽、空时分组(Space-time blockcoding,简称STBC)技术的使用、前向纠错(Forward Error Correction,简称FEC)编码方法等。
(3)获取所述第三信号的频谱特性,若所述第三信号的频谱与预设干扰源的频谱特性相匹配,则确定所述第三信号为干扰信号。
可选的,接收设备还可以从预先存储的干扰特征集中选取N个不同干扰源对应的干扰特征向量作为所述干扰特征,其中,干扰特征集中记录有多类干扰源对应的干扰特征向量,每类干扰源对应的干扰特征向量可以根据多次记录的干扰信号的干扰特征向量获得,例如:
分别计算至少一次记录的干扰特征向量与第一类干扰源的干扰特征向量之间的相关度,若每次记录的干扰特征向量与第一类干 扰源的干扰特征向量之间的相关度均大于预设门限值,则将所述至少一次记录的干扰特征向量记录为第一类干扰源对应的干扰特征向量。
其中,所述预设门限值可以根据需要进行设置,本发明实施例对比不进行限制;所述相关度的计算可以采用现有技术,在此不再赘述。
此外,干扰特征集中还可以包含:每类干扰源对应的占用信道时间或者信号能量;可选的,所述接收设备还可以从预先存储的干扰特征集中选择N个不同干扰源对应的干扰特征向量作为所述干扰特征可以包括:
接收设备从预先存储的干扰特征集中选择占用信道时间最长或者信号能量最高的N个不同干扰源对应的干扰特征向量作为所述干扰特征。
示例性的,本发明实施例中,接收设备可以基于下述(a)正交法、(b)矩阵求逆、(c)酉矩阵分解中的任一种方式根据所述信道特征和所述干扰特征获取所述干扰抵消矩阵:
(a)正交法
当采用正交法获得干扰抵消矩阵时,可以采用正交法计算出一个或多个干扰抵消向量,将所述干扰抵消向量组合成干扰抵消矩阵,其中,采用正交法获取干扰抵消向量的过程具体如下:
获取与所述干扰特征中干扰特征向量相垂直的、且与所述信道特征夹角最小的一个或与所述信道特征夹角小于预设角度的特征向量作为所述干扰抵消向量。
其中,所述相垂直可以为近似接近于90度垂直或完全为90度垂直(理想状态下);所述预设角度可以根据需要进行设置,在此不再赘述。
(b)矩阵求逆
将所述信道特征与所述干扰特征组合成第一联合矩阵;
对所述第一联合矩阵进行矩阵求逆运算,获得逆矩阵;
将所述逆矩阵中与所述信道特征对应的M个向量或将与所述信道特征对应的M个线性组合后的向量组合成所述干扰抵消矩阵。
其中,与所述信道特征对应的M个向量可以为:列(行)数序号与所述信道特征中需要抵消干扰的数据流对应的信道特征所处的行(列)数序号相等的向量;例如,需要抵消干扰的数据流的个数为M,且信道矩阵中需要抵消干扰的数据流对应第一联合矩阵的第2列和第3列,则将逆矩阵中的第2行和第3行的向量组合形成干扰抵消矩阵。
其中,所述线性组合可以为将与所述信道矩阵包含的向量乘以一个系数,所述系数是一个缩放因子,可将向量的幅度调整到一定的范围,避免引入过大定点化误差。
需要说明的是,当第一联合矩阵的行数、列数不相等时,或者第一联合矩阵不满秩时,对所述第一联合矩阵进行矩阵求逆运算可以为对第一联合矩阵求伪逆。
此外,为了避免求出的干扰抵消矩阵的幅度过大,本发明实施例中,还可以对第一联合矩阵进行多次近似求逆,从中选择一个满足要求的前M行向量作为所述干扰抵消矩阵,具体如下:
对所述第一联合矩阵进行至少一次近似求逆,获得至少一个近似逆矩阵;
分别利用所述至少一个近似逆矩阵中与所述信道特征对应的M个向量计算所述第一信号的信噪比,获得至少一个信噪比;
将所述至少一个信噪比中,最大信噪比对应的M个向量或者将最大信噪比对应的M个线性组合后向量组合成所述干扰抵消矩阵。
例如:将干扰特征加入信道矩阵后面的列形成联合矩阵H′:
Figure PCTCN2015078597-appb-000003
需要说明的,本发明实施例中可以将干扰特征加入联合信道矩阵后面的列,也可以加入到联合信道矩阵前面的列;(H1i,H2i,…,HNri)是第i个数据流对应的信道特征,(IC1i,IC2i,…,ICNri)是第i个要干扰源的干扰特征。
然后,对H′求逆得到:
Figure PCTCN2015078597-appb-000004
若需要抵消前M个数据流中的干扰,则取逆矩阵H′-1中前M行向量作为干扰抵消矩阵C,以抵消M条数据流中的干扰,或者将逆矩阵H′-1中前M行向量与系数D相乘作为干扰抵消矩阵C:
Figure PCTCN2015078597-appb-000005
其中D是一个对角矩阵,是一个缩放因子,可将C的幅度调整到一定的范围,避免引入过大定点化误差。
另外,当H′矩阵的行数、列数不相等,或者H′矩阵不满秩时,可以对H′L求伪逆。
此外,为避免干扰抵消矩阵幅度太大,可以对H′-1进行多次近似求逆,从中选择一个满足要求的干扰抵消矩阵,具体如下:
对H′-1矩阵进行至少一次近似求逆,获得至少一个近似逆矩阵H′-1
分别利用所述至少一个包含近似逆矩阵H′-1中前M行向量的干扰抵消矩阵计算接收到信号的信噪比;
将最大信噪比对应的干扰抵消矩阵作为干扰抵消矩阵C。
优选的,当接收到多条数据流时,可以根据下述公式计算信 号的信噪比SNR:
Figure PCTCN2015078597-appb-000006
其中,diag表示对矩阵求对角线,x为发送信号,diag(C·H)·x为抵消干扰后的有用信号,non-diag(C·H)·x为有用信号之间的干扰;sumByRow表示按行求和,sumByRow(C·IC+C·BNG)为干扰源及噪声的干扰,BNG是系统中原有的每个天线接收到的背景噪声幅度。
(c)酉矩阵分解
将所述信道特征与所述干扰特征组合成第二联合矩阵H′;
对所述第二联合矩阵进行酉矩阵分解,获得H′=U×S×V;其中,所述U和所述V为一个酉矩阵,所述S为一个对角矩阵;
向发送设备发送所述V矩阵,以使得发送设备根据V矩阵设置预编码系数。
可选的,将所述U矩阵与所述信道特征对应的M个向量组合的矩阵共轭转置后作为所述干扰抵消矩阵。
其中,与所述信道特征对应的M个向量可以为:列(行)数序号与所述信道特征中需要抵消干扰的数据流对应的信道特征所处的行(列)数序号相等的向量;酉矩阵分解可以为奇异值分解(SVD)、几何平均值分解(GMD)等分解方式中的任一种分解方式。
例如:将干扰特征加入信道矩阵后面的列形成联合矩阵H′:
Figure PCTCN2015078597-appb-000007
需要说明的,本发明实施例中可以将干扰特征加入联合信道矩阵后面的列,也可以加入到联合信道矩阵前面的列;(H1i,H2i,…,HNri)是第i个数据流对应的信道特征,(IC1i,IC2i,…,ICNri)是第i个要干扰源的干扰特征。
然后,对H′进行酉矩阵分解,获得H′=U×S×V;其中,所述U和所述V为一个酉矩阵,所述S为一个对角矩阵;
向发送设备发送所述V矩阵,以使得发送设备根据V矩阵设置预编码系数;
若需要抵消前M个数据流中的干扰,则将所述U矩阵前M列向量组成的矩阵共轭转置后作为所述干扰抵消矩阵。
进一步的,为了避免在抵消信号中的干扰的同时,将信号中的有用数据消弱,本发明实施例中,在将所述干扰抵消矩阵与所述第一信号相乘之前,所述方法还包括:
计算所述干扰矩阵中每个干扰特征向量与传输所述第一信号的信道的信道特征的每一行向量或列向量的相关度;
确定所述干扰矩阵的每个干扰特征向量与传输所述第一信号的信道的信道特征的每一行向量或列向量的相关度是否小于第二预设阈值;
所述将所述干扰抵消矩阵与所述第一信号相乘具体包括:
若确定小于第二预设阈值,则将所述干扰抵消矩阵与所述第一信号相乘。
其中,第二预设阈值可以根据需要进行设置,本发明实施例对比不进行限制,所述相关度小于第二预设阈值,则表示该干扰源的干扰特征与所述信道矩阵不相关,在用干扰抵消向量抵消信号中干扰的同时不会明显消弱有用信号的强度;所述相关度大于等于第二预设阈值,则表示该干扰源的干扰特征与所述信道矩阵相关,在用干扰抵消向量抵消信号中干扰的同时也会消弱信号中有用信号的强度,不可用所述干扰抵消矩阵与所述第一信号相乘。
进一步的,通常情况下,在每个接收周期内接收到第一部分信号时,需要对传输信号的信道进行空闲信道评估(Clear Channel Assessment,CCA),若信道为忙信道,则对接收到的第一部分信号进行解调,获得用于估计信道特征和判断信号是否为有用信号的SIG;若信道为闲信道,则不做任何处理;
然而,在某种情况下,在发送设备没有发送信号的情况下,接收设备接收到干扰且接收能量大于阈值(相当于信道被干扰完全所占用),则接收设备会误认为信道繁忙,为了避免接收设备将被干扰所占用的信道误认为发送设备正在传输信号的忙信道,本发明实施例中,还可以对接收到的第一部分信号进行干扰消除,例如,以第二信号为例,对接收到的第二信号时就进行干扰抵消为:
用预先存储的第一干扰抵消向量接收所述第二信号,以抵消所述第二信号中的干扰;
确定接收到的所述第二信号的信号能量是否大于等于第三预设阈值;
所述根据所述第二信号估计发送所述第二信号的信道特征具体包括:
若大于等于所述第三预设阈值,则确定信道忙,根据所述第二信号估计发送所述第二信号的信道特征;若确定抵消干扰后的第一信号的信号能量小于第三预设阈值,则确定信道闲,可以利用信道向发送设备发送数据。
由上可知,本发明实施例提供一种干扰抵消方法,接收到第一信号后,用获取的干扰抵消矩阵与所述第一信号相乘,并将相乘后的信号解调获得M条数据流,以抵消M条数据流中的干扰,使得解调后获得数据为抵消干扰后的数据,大大提高了数据传输的可靠性。
实施例二
图5示出了本发明实施例提供的一种接收设备50的结构图,应用于执行实施例一所述的干扰抵消方法,所述接收设备配置有Nr个接收天线,用于接收Nt个发送天线或空间流(space stream)或空间时间流(space-time stream)输出的信号,所述Nr为大于等于2的整数;所述Nr为大于等于2的整数,所述Nt为大于等于1的整数;所述设备可以包括:
接收单元501,用于接收第一信号;其中,所述第一信号包含 Nr个接收天线接收到的Nt个发送天线或空间流或空间时间流输出的信号经过信道后的信号和噪声信号。
通常情况下,在WLAN系统中,接收设备可以在一个接收周期内先后接收到至少2部分信号:第一部分信号和第二部分信号;其中,第一部分信号经解调后可获得相应的包含多种用途的前导码字(也称作协议头),如用来指示数据的到达、指示数据流的格式、估计信道特征、估算接收信号能量强度、估计频率误差和时间误差等;第二部分信号可以通过不同的解调方式解调后获得多条数据流。
例如,图4示出了802.11n系列标准中一个接收周期内的信号接收格式,如图4所示,该信号可以包括:第一部分信号和第二部分信号;其中,所述第一部分信号经解调后可对应获得:短训练域(Short Training field,检测STF)、域消息(Signal Field,简称SIG)以及长训练域(Long Training field,简称LTF)信息,STF可用来进行空闲信道评估(Clear Channel Assesement,简称CCA)检测接收信号到达,SIG可用于判断信号是否为干扰信号,LTF可用来估计信道特征;第二部分信号解调后可对应获得数据(Data)。
可选的,第一信号可以为任一接收周期内的第二部分信号,可被解调出多条数据流,可以未被干扰源干扰,也可以被干扰源所干扰;当第一信号未被干扰源干扰时,第一信号仅包含Nr个接收天线接收到的Nt个发送天线或空间流或空间时间流输出的信号经过信道后的信号和噪声信号,可以表示为:y=H·x+n;当所述第一信号被干扰源所干扰时,第一信号还可以包含干扰信号的合成信号,可以采用图1所示信道模型下的被干扰源干扰的信号表示方式表示:y=H·x+IC·I+n,在此不再赘述。
获取单元502,用于获取干扰抵消矩阵;所述干扰抵消矩阵包含M个干扰抵消向量,每个干扰抵消向量包含Nr个干扰抵消系数,所述每个干扰抵消向量与N个干扰源中任一个干扰源在Nr个接收天线上的干扰特征向量的相关度小于第一预设阈值;所述M为预先 设置的干扰抵消向量的个数;所述N为预先设置的干扰的个数。
其中,M可以根据需要进行设置,可以为1个或多个,当M=1时,步骤302中的干扰抵消矩阵仅包含1个干扰抵消向量,即该干扰抵消矩阵可以认为是一个干扰抵消向量;其中,干扰源的个数N可以根据对接收设备所处环境下干扰情况的统计测量获得,可以为一个干扰源,也可以为多个干扰源,本发明实施例对此不进行限制。
其中,本发明实施例中,向量之间的相关度可以指:向量之间的夹角大小,可以用向量夹角的余弦值或者向量夹角余弦值的绝对值表示;若相关度接近0度或180度,则表示向量之间接近平行,向量之间相关;若相关度接近90度,则表示向量之间接近垂直,向量之间不相关;通常情况下,可以采用余弦相关性、皮尔逊积矩(Pearson)相关系数等常用的计算方法获得向量之间的相关度。
所述第一预设阈值可以根据需要设置为尽可能的趋向于零或等于零(理想状态下),所述干扰抵消向量与所述干扰特征中每列干扰特征向量相关度小于第一预设阈值表示:干扰抵消向量与每个干扰源对应的干扰特征不相关,可以用该干扰抵消向量最大程度的抵消所述干扰源的干扰;所述干扰抵消向量与所述干扰特征中每列干扰特征向量相关度大于等于第一预设阈值表示:干扰抵消向量与每个干扰源对应的干扰特征之间有一定的关联性,不能用该干扰抵消向量抵消所述干扰源的干扰。
干扰抵消单元503,用于将所述获取单元获取到的干扰抵消矩阵与所述接收单元接收到的第一信号相乘,并将相乘后的信号解调获得数据流。
进一步的,为了获取干扰抵消矩阵,在图5的基础上,参见图5A所示,所述接收设备50还可以包括:信道估计单元504;
所述接收单元501,还用于在第一接收周期内接收第二信号,其中,所述第二信号为Nr个接收天线接收到的信号;
所述信道估计单元504,用于根据所述接收单元接收到的第二信号估计传输所述第二信号的信道的信道特征;其中,所述信道特 征为Nr乘Nt的矩阵;
所述获取单元502,具体用于:
获取干扰特征,其中,所述干扰特征由N个向量组成,第i个向量为第i个干扰源在所述Nr个接收天线上的干扰特征向量;
并根据所述信道估计单元估计出的信道特征和获取到的所述干扰特征获取干扰抵消矩阵。
可选的,在所述接收单元501接收到第二信号之后,所述获取单元502还需要根据解调后的第二信号判断第二信号是否为有用信号,若所述第二信号为有用信号,再根据传输所述第二信号的信道的信道特征,根据所述信道特征和获取到的干扰特征获取所述干扰抵消矩阵;若第二信号为干扰信号,则记录所述第二信号的干扰特征,结束第一接收周期内后续的接收过程,监测下一接收周期中的信号;需要说明的是,本实施例所述的有用信号为被干扰源干扰的信号,可以包含发送端发送的信号和干扰信号,如有用信号y=H·x+IC·I+n;而干扰信号为不包含发送端发送的信号,仅被干扰源干扰的信号,如干扰信号:y=IC·I。
其中,信道估计单元504可以采用现有技术估计信道特征,在此不再赘述。
其中,第二信号为第一接收周期中的第一部分信号,经解调后可获得用于指示数据的到达、指示数据流的格式、估计信道特征、估算接收信号能量强度、估计频率误差和时间误差等的前导码字,可以与第一信号同时处于第一接收周期内,也可以处于所述第一信号所处接收周期之前的第一接收周期内;当处于所述第一信号所处接收周期之前的第一接收周期时,所述干扰抵消矩阵中用于抵消第一信号解调后的数据流的干扰抵消向量为历史存储的干扰抵消向量,而不是根据本次接收周期接收到的第一部分信号估计出的信道矩阵获得的干扰抵消向量。
进一步的,所述获取单元502可以将预先记录的干扰信号的干扰特征向量作为干扰特征中的干扰特征向量,具体如下:
所述接收单元501,还用于在第二接收周期内接收第三信号;
所述获取单元502,具体用于判断所述第三信号是否为干扰信号;
若确定所述第三信号为干扰信号,则记录所述第三信号在Nr个接收天线上的干扰特征向量;
将所述第三信号在Nr个接收天线上的干扰特征向量作为所述干扰特征向量;或者
对所述第三信号在Nr个接收天线上的干扰特征向量与其他至少一个接收周期接收到的干扰信号在Nr个接收天线上的干扰特征向量进行加权求和;
将加权求和后的结果记录为所述第三信号在Nr个接收天线上的干扰特征向量。
其中,所述第二接收周期可以为所述第一接收周期之前的任一接收周期。
具体的,所述获取单元502可以通过下述(1)(2)(3)中的任一种方式判断所述第三信号是否为干扰信号:
(1)对所述第三信号进行解调,若解调出的数据帧的至少一个域与预设干扰源的域相同,则确定所述第三信号为干扰信号。
其中,数据帧可以为物理(MAC)层帧或更高层业务的帧(如IP包)等;所述域可以为数据帧的地址域,如:802.11MAC帧的域可以为目的地址、源地址,IP包的域可以为IP包包含的任何一个地址;也可以是用于标识WLAN的标识,如:业务集标识(Service Set Identification,简称SSID)、基本业务集标识(Basic Service Set Identification,简称BSSID)等。
例如,若预设干扰源的域为A1,第三信号解调后为MAC帧,且目的地址为A1,则确定第三信号为干扰信号。
(2)解调第三信号对应的域消息SIG;其中,所述第SIG包括:数据流信息和校验字段;
根据预设算法计算第一校验字段,若所述第一校验字段与所 述SIG中包含的校验字段不同,则确定所述第三信号为干扰信号;
或者,若所述数据流信息的数据格式与预设数据格式不同,则确定所述第三信号为干扰信号。
其中,数据流信息是解调信号获得数据流所必要的信息,包括:调制和编码方案(Modulation and Coding Scheme,简称MCS)、信道带宽、空时分组(Space-time block coding,简称STBC)技术的使用、前向纠错(Forward Error Correction,简称FEC)编码方法等。
(3)获取所述第三信号的频谱特性,若所述第三信号的频谱与预设干扰源的频谱特性相匹配,则确定所述第三信号为干扰信号。
可选的,接收设备还可以从预先存储的干扰特征集中选取N个不同干扰源对应的干扰特征向量作为所述干扰特征,其中,干扰特征集中记录有多类干扰源对应的干扰特征向量,每类干扰源对应的干扰特征向量可以根据多次记录的干扰信号的干扰特征向量获得,例如:
分别计算至少一次记录的干扰特征向量与第一类干扰源的干扰特征向量之间的相关度,若每次记录的干扰特征向量与第一类干扰源的干扰特征向量之间的相关度均大于预设门限值,则将所述至少一次记录的干扰特征向量记录为第一类干扰源对应的干扰特征向量。
其中,所述预设门限值可以根据需要进行设置,本发明实施例对比不进行限制;所述相关度的计算可以采用现有技术,在此不再赘述。
此外,干扰特征集中还可以包含:每类干扰源对应的占用信道时间或者信号能量;可选的,所述接收设备还可以从预先存储的干扰特征集中选择N个不同干扰源对应的干扰特征向量作为所述干扰特征可以包括:
接收设备从预先存储的干扰特征集中选择占用信道时间最长 或者信号能量最高的N个不同干扰源对应的干扰特征向量作为所述干扰特征。
进一步的,所述获取单元502可以可以基于下述(a)正交法、(b)矩阵求逆、(c)酉矩阵分解中的任一种方式根据所述信道特征和所述干扰特征获取所述干扰抵消矩阵:
(a)正交法
当采用正交法获得干扰抵消矩阵时,所述获取单元502可以采用正交法计算出一个或多个干扰抵消向量,将所述干扰抵消向量组合成干扰抵消矩阵,具体如下:
获取与所述干扰特征中干扰特征向量相垂直的、且与所述信道特征夹角最小的一个或与所述信道特征夹角小于预设角度的特征向量作为所述干扰抵消向量。
其中,所述相垂直可以为近似接近于90度垂直或完全为90度垂直(理想状态下);所述预设角度可以根据需要进行设置,在此不再赘述。
(b)矩阵求逆
所述获取单元502,具体用于:
将所述信道特征与所述干扰特征组合成第一联合矩阵;
对所述第一联合矩阵进行矩阵求逆运算,获得逆矩阵;
将所述逆矩阵中与所述信道特征对应的M个向量或将与所述信道特征对应的M个线性组合后的向量组合成所述干扰抵消矩阵。
其中,与所述信道特征对应的M个向量可以为:列(行)数序号与所述信道特征中需要抵消干扰的数据流对应的信道特征所处的行(列)数序号相等的向量;例如,需要抵消干扰的数据流的个数为M,且信道矩阵中需要抵消干扰的数据流对应第一联合矩阵的第2列和第3列,则将逆矩阵中的第2行和第3行的向量组合形成干扰抵消矩阵。
其中,所述线性组合可以为将与所述信道矩阵包含的向量乘 以一个系数,所述系数是一个缩放因子,可将向量的幅度调整到一定的范围,避免引入过大定点化误差。
需要说明的是,当第一联合矩阵的行数、列数不相等时,或者第一联合矩阵不满秩时,对所述第一联合矩阵进行矩阵求逆运算可以为对第一联合矩阵求伪逆。
此外,为了避免求出的干扰抵消矩阵的幅度过大,本发明实施例中,获取单元502还可以对第一联合矩阵进行多次近似求逆,从中选择一个满足要求的前M行向量作为所述干扰抵消矩阵,具体如下:
对所述第一联合矩阵进行至少一次近似求逆,获得至少一个近似逆矩阵;
分别利用所述至少一个近似逆矩阵中与所述信道特征对应的M个向量计算所述第一信号的信噪比,获得至少一个信噪比;
将所述至少一个信噪比中,最大信噪比对应的M个向量或者将最大信噪比对应的M个线性组合后向量组合成所述干扰抵消矩阵。
例如:将干扰特征加入信道矩阵后面的列形成联合矩阵H′:
Figure PCTCN2015078597-appb-000008
需要说明的,本发明实施例中可以将干扰特征加入联合信道矩阵后面的列,也可以加入到联合信道矩阵前面的列;(H1i,H2i,…,HNri)是第i个数据流对应的信道特征,(IC1i,IC2i,…,ICNri)是第i个要干扰源的干扰特征。
然后,对H′求逆得到:
Figure PCTCN2015078597-appb-000009
若需要抵消前M个数据流中的干扰,则取逆矩阵H′-1中前M行向量作为干扰抵消矩阵C,以抵消M条数据流中的干扰,或者将逆矩阵H′-1中前M行向量与系数D相乘作为干扰抵消矩阵C:
Figure PCTCN2015078597-appb-000010
其中D是一个对角矩阵,是一个缩放因子,可将C的幅度调整到一定的范围,避免引入过大定点化误差。
另外,当H′矩阵的行数、列数不相等,或者H′矩阵不满秩时,可以对H′L求伪逆。
此外,为避免干扰抵消矩阵幅度太大,对H′-1进行多次近似求逆,从中选择一个满足要求的干扰抵消矩阵,具体如下:
对H′-1矩阵进行至少一次近似求逆,获得至少一个近似逆矩阵H′-1
分别利用所述至少一个包含近似逆矩阵H′-1中前M行向量的干扰抵消矩阵计算接收到信号的信噪比;
将最大信噪比对应的干扰抵消矩阵作为干扰抵消矩阵C。
优选的,当接收到多条数据流时,可以根据下述公式计算信号的信噪比SNR:
Figure PCTCN2015078597-appb-000011
其中,diag表示对矩阵求对角线,x为发送信号,diag(C·H)·x为抵消干扰后的有用信号,non-diag(C·H)·x为有用信号之间的干扰; sumByRow表示按行求和,sumByRow(C·IC+C·BNG)为干扰源及噪声的干扰,BNG是系统中原有的每个天线接收到的背景噪声幅度。
(c)酉矩阵分解
进一步的,为了采用酉矩阵分解获取干扰抵消矩阵,在图5A的基础上,参见图5B所示,所述接收设备还可以包括:分解单元505、发送单元506;
所述分解单元505,用于将所述信道估计单元504估计出的信道特征与所述获取单元502获取到的干扰特征组合成第二联合矩阵H′;
对所述第二联合矩阵进行酉矩阵分解,获得H′=U×S×V;其中,所述U和所述V为一个酉矩阵,所述S为一个对角矩阵;
所述发送单元506,用于向发送设备发送所述分解单元505分解出的V矩阵,以使得所述发送设备根据所述V矩阵设置预编码系数。
所述获取单元502,具体用于:
将所述U矩阵与所述信道特征对应的M个向量组合的矩阵共轭转置后作为所述干扰抵消矩阵。
其中,与所述信道特征对应的M个向量可以为:列(行)数序号与所述信道特征中需要抵消干扰的数据流对应的信道特征所处的行(列)数序号相等的向量;酉矩阵分解可以为奇异值分解(SVD)、几何平均值分解(GMD)等分解方式中的任一种分解方式。
例如:将干扰特征加入信道矩阵后面的列形成联合矩阵H′:
Figure PCTCN2015078597-appb-000012
需要说明的,本发明实施例中可以将干扰特征加入联合信道矩阵后面的列,也可以加入到联合信道矩阵前面的列;(H1i,H2i,…,HNri)是第i个数据流对应的信道特征,(IC1i,IC2i,…,ICNri) 是第i个要干扰源的干扰特征。
然后,对H′进行酉矩阵分解,获得H′=U×S×V;其中,所述U和所述V为一个酉矩阵,所述S为一个对角矩阵;
向发送设备发送所述V矩阵,以使得发送设备根据V矩阵设置预编码系数;
若需要抵消前M个数据流中的干扰,则将所述U矩阵前M列向量组成的矩阵共轭转置后作为所述干扰抵消矩阵。
如此,接收设备可以利用获得的干扰抵消矩阵,抵消多条数据流中的干扰,提供数据传输的可靠性。
进一步的,本发明实施例中,为了避免在抵消信号中的干扰的同时,将信号中的有用数据消弱,在图5A的基础上,参见图5C所示,所述接收设备还可以包括:计算单元507;
所述信道估计单元504,还用于估计传输所述第一信号的信道的信道特征;
所述计算单元507,用于在所述干扰抵消单元503将所述干扰抵消矩阵与所述第一信号相乘之前,计算所述干扰矩阵中每个干扰特征向量与传输所述第一信号的信道的信道特征的每一行向量或列向量的相关度;
确定所述干扰矩阵的每个干扰特征向量与传输所述第一信号的信道的信道特征的每一行向量或列向量的相关度是否小于第二预设阈值;
所述干扰抵消单元503,具体用于:
若确定小于第二预设阈值,则将所述干扰抵消矩阵与所述第一信号相乘。
其中,第二预设阈值可以根据需要进行设置,本发明实施例对比不进行限制,所述相关度小于第二预设阈值,则表示该干扰源的干扰特征与所述信道矩阵不相关,在用干扰抵消向量抵消信号中干扰的同时不会明显消弱有用信号的强度;所述相关度大于等于第二预设阈值,则表示该干扰源的干扰特征与所述信道矩阵相关,在 用干扰抵消向量抵消信号中干扰的同时也会消弱信号中有用信号的强度,不可用所述干扰抵消矩阵与所述第一信号相乘。
通常情况下,在每个接收周期内接收到第一部分信号时,需要对传输信号的信道进行空闲信道评估(Clear Channel Assessment,CCA),若信道为忙信道,则对接收到的第一部分信号进行解调,获得用于估计信道特征和判断信号是否为有用信号的SIG;若信道为闲信道,则不做任何处理;
然而,在某种情况下,在发送设备没有发送信号的情况下,接收设备接收到干扰且接收能量大于阈值(相当于信道被干扰完全所占用),则接收设备会误认为信道繁忙,为了避免接收设备将被干扰所占用的信道误认为发送设备正在传输信号的忙信道,本发明实施例中,所述干扰抵消单元503,还用于:
在所述信道估计单元504根据所述第二信号估计发送所述第二信号的信道特征之前,用预先存储的第一干扰抵消向量接收所述第二信号,以抵消所述第二信号中的干扰;
确定接收到的所述第二信号的信号能量是否大于等于第三预设阈值;
所述信道估计单元504,具体用于:
若大于等于所述第三预设阈值,则确定信道忙,根据所述第二信号估计发送所述第二信号的信道特征;若确定抵消干扰后的第一信号的信号能量小于第三预设阈值,则确定信道闲,可以利用信道向发送设备发送数据。
由上可知,本发明实施例提供一种接收设备,接收到第一信号后,用获取的干扰抵消矩阵与所述第一信号相乘,并将相乘后的信号解调获得M条数据流,以抵消M条数据流中的干扰,使得解调后获得数据为抵消干扰后的数据,大大提高了数据传输的可靠性。
实施例三
图6示出了本发明实施例提供的一种接收设备60的结构图, 应用于执行实施例一所述的干扰抵消方法,如图6所示,所述设备可以包括:收发器601,处理器602、存储器603、至少一个通信总线604,用于实现这些设备之间的连接和相互通信;
收发器601,可以配置有Nr个接收天线,用于接收Nt个发送天线或空间流(space stream)或空间时间流(space-time stream)输出的信号,所述Nr为大于等于2的整数;所述Nt为大于等于1的整数;用于与外部网元之间进行数据传输。
处理器602可能是一个中央处理器(英文:central processing unit,简称为CPU)。
存储器603,可以是易失性存储器(英文:volatile memory),例如随机存取存储器(英文:random-access memory,缩写:RAM);或者非易失性存储器(英文:non-volatile memory),例如只读存储器(英文:read-only memory,缩写:ROM),快闪存储器(英文:flash memory),硬盘(英文:hard disk drive,缩写:HDD)或固态硬盘(英文:solid-state drive,缩写:SSD);或者上述种类的存储器的组合,并向处理器602提供指令和数据。
收发器601,用于接收第一信号;其中,所述第一信号包含Nr个接收天线接收到的Nt个发送天线或空间流或空间时间流输出的信号经过信道后的信号和噪声信号。
通常情况下,在WLAN系统中,接收设备可以在一个接收周期内先后接收到至少2部分信号:第一部分信号和第二部分信号;其中,第一部分信号经解调后可获得相应的包含多种用途的前导码字(也称作协议头),如用来指示数据的到达、指示数据流的格式、估计信道特征、估算接收信号能量强度、估计频率误差和时间误差等;第二部分信号可以通过不同的解调方式解调后获得多条数据流。
例如,图4示出了802.11n系列标准中一个接收周期内的信号接收格式,如图4所示,该信号可以包括:第一部分信号和第二部分信号;其中,所述第一部分信号经解调后可对应获得:短训练域 (Short Training field,检测STF)、域消息(Signal Field,简称SIG)以及长训练域(Long Training field,简称LTF)信息,STF可用来进行空闲信道评估(Clear Channel Assesement,简称CCA)检测接收信号到达,SIG可用于判断信号是否为干扰信号,LTF可用来估计信道特征;第二部分信号解调后可对应获得数据(Data)。
可选的,第一信号可以为任一接收周期内的第二部分信号,可被解调出多条数据流,可以未被干扰源干扰,也可以被干扰源所干扰;当第一信号未被干扰源干扰时,第一信号仅包含Nr个接收天线接收到的Nt个发送天线或空间流或空间时间流输出的信号经过信道后的信号和噪声信号,可以表示为:y=H·x+n;当所述第一信号被干扰源所干扰时,第一信号还可以包含干扰信号的合成信号,可以采用图1所示信道模型下的被干扰源干扰的信号表示方式表示:y=H·x+IC·I+n,在此不再赘述。
处理器602,用于获取干扰抵消矩阵;所述干扰抵消矩阵包含M个干扰抵消向量,每个干扰抵消向量包含Nr个干扰抵消系数,所述每个干扰抵消向量与N个干扰源中任一个干扰源在Nr个接收天线上的干扰特征向量的相关度小于第一预设阈值;所述M为预先设置的干扰抵消向量的个数;所述N为预先设置的干扰的个数。
将所述获取单元获取到的干扰抵消矩阵与所述接收单元接收到的第一信号相乘获得M个信号,并将所述M个信号解调获得M条数据流。
其中,M可以根据需要进行设置,可以为1个或多个,当M=1时,步骤302中的干扰抵消矩阵仅包含1个干扰抵消向量,即该干扰抵消矩阵可以认为是一个干扰抵消向量;其中,干扰源的个数N可以根据对接收设备所处环境下干扰情况的统计测量获得,可以为一个干扰源,也可以为多个干扰源,本发明实施例对此不进行限制。
其中,本发明实施例中,向量之间的相关度可以指:向量之间的夹角大小,可以用向量夹角的余弦值或者向量夹角余弦值的绝对值表示;若相关度接近0度或180度,则表示向量之间接近平行, 向量之间相关;若相关度接近90度,则表示向量之间接近垂直,向量之间不相关;通常情况下,可以采用余弦相关性、皮尔逊积矩(Pearson)相关系数等常用的计算方法获得向量之间的相关度。
所述第一预设阈值可以根据需要设置为尽可能的趋向于零或等于零(理想状态下),所述干扰抵消向量与所述干扰特征中每列干扰特征向量相关度小于第一预设阈值表示:干扰抵消向量与每个干扰源对应的干扰特征不相关,可以用该干扰抵消向量最大程度的抵消所述干扰源的干扰;所述干扰抵消向量与所述干扰特征中每列干扰特征向量相关度大于等于第一预设阈值表示:干扰抵消向量与每个干扰源对应的干扰特征之间有一定的关联性,不能用该干扰抵消向量抵消所述干扰源的干扰。
进一步的,所述收发器601,还用于在第一接收周期内接收第二信号,其中,所述第二信号为Nr个接收天线接收到的信号;
所述处理器602,具体用于:
根据所述接收单元接收到的第二信号估计传输所述第二信号的信道的信道特征;其中,所述信道特征为Nr乘Nt的矩阵;
获取干扰特征,其中,所述干扰特征由N个向量组成,所述N为干扰源的个数,第i个向量为第i个干扰源在所述Nr个接收天线上的干扰特征向量;
并根据所述信道估计单元估计出的信道特征和获取到的所述干扰特征获取干扰抵消矩阵;其中,所述干扰抵消矩阵中的每个干扰抵消向量与所述干扰特征中每个干扰特征向量的相关度小于第一预设阈值。
可选的,在接收到第二信号之后,还需要根据解调后的第二信号判断第二信号是否为有用信号,若所述第二信号为有用信号,再根据传输所述第二信号的信道的信道特征,根据所述信道特征和获取到的干扰特征获取所述干扰抵消矩阵;若第二信号为干扰信号,则记录所述第二信号的干扰特征,结束第一接收周期内后续的接收过程,监测下一接收周期中的信号;需要说明的是,本实施例 所述的有用信号为被干扰源干扰的信号,可以包含发送端发送的信号和干扰信号,如有用信号y=H·x+IC·I+n;而干扰信号为不包含发送端发送的信号,仅被干扰源干扰的信号,如干扰信号:y=IC·I。
其中,处理器602可以采用现有技术估计信道特征,在此不再赘述。
其中,第二信号为第一接收周期中的第一部分信号,经解调后可获得用于指示数据的到达、指示数据流的格式、估计信道特征、估算接收信号能量强度、估计频率误差和时间误差等的前导码字,可以与第一信号同时处于第一接收周期内,也可以处于所述第一信号所处接收周期之前的第一接收周期内;当处于所述第一信号所处接收周期之前的第一接收周期时,所述干扰抵消矩阵中用于抵消第一信号解调后的数据流的干扰抵消向量为历史存储的干扰抵消向量,而不是根据本次接收周期接收到的第一部分信号估计出的信道矩阵获得的干扰抵消向量。
进一步的,所述处理器602可以将预先记录的干扰信号的干扰特征向量作为干扰特征中的干扰特征向量,具体如下:
所述收发器601,还用于在第二接收周期内接收第三信号;
所述处理器602,具体用于判断所述第三信号是否为干扰信号;
若确定所述第三信号为干扰信号,则记录所述第三信号在Nr个接收天线上的干扰特征向量;
将所述第三信号在Nr个接收天线上的干扰特征向量作为所述干扰特征向量;或者
对所述第三信号在Nr个接收天线上的干扰特征向量与其他至少一个接收周期接收到的干扰信号在Nr个接收天线上的干扰特征向量进行加权求和;
将加权求和后的结果记录为所述第三信号在Nr个接收天线上的干扰特征向量。
其中,所述第二接收周期可以为所述第一接收周期之前的任一接收周期。
具体的,所述处理器602可以通过下述(1)(2)(3)中的任一种方式判断所述第三信号是否为干扰信号:
(1)对所述第三信号进行解调,若解调出的数据帧的至少一个域与预设干扰源的域相同,则确定所述第三信号为干扰信号。
其中,数据帧可以为物理(MAC)层帧或更高层业务的帧(如IP包)等;所述域可以为数据帧的地址域,如:802.11MAC帧的域可以为目的地址、源地址,IP包的域可以为IP包包含的任何一个地址;也可以是用于标识WLAN的标识,如:业务集标识(Service Set Identification,简称SSID)、基本业务集标识(Basic Service Set Identification,简称BSSID)等。
例如,若预设干扰源的域为A1,第三信号解调后为MAC帧,且目的地址为A1,则确定第三信号为干扰信号。
(2)解调第三信号对应的域消息SIG;其中,所述第SIG包括:数据流信息和校验字段;
根据预设算法计算第一校验字段,若所述第一校验字段与所述SIG中包含的校验字段不同,则确定所述第三信号为干扰信号;
或者,若所述数据流信息的数据格式与预设数据格式不同,则确定所述第三信号为干扰信号。
其中,数据流信息是解调信号获得数据流所必要的信息,包括:调制和编码方案(Modulation and Coding Scheme,简称MCS)、信道带宽、空时分组(Space-time block coding,简称STBC)技术的使用、前向纠错(Forward Error Correction,简称FEC)编码方法等。
(3)获取所述第三信号的频谱特性,若所述第三信号的频谱与预设干扰源的频谱特性相匹配,则确定所述第三信号为干扰信号。
可选的,接收设备还可以从预先存储的干扰特征集中选取N 个不同干扰源对应的干扰特征向量作为所述干扰特征,其中,干扰特征集中记录有多类干扰源对应的干扰特征向量,每类干扰源对应的干扰特征向量可以根据多次记录的干扰信号的干扰特征向量获得,例如:
分别计算至少一次记录的干扰特征向量与第一类干扰源的干扰特征向量之间的相关度,若每次记录的干扰特征向量与第一类干扰源的干扰特征向量之间的相关度均大于预设门限值,则将所述至少一次记录的干扰特征向量记录为第一类干扰源对应的干扰特征向量。
其中,所述预设门限值可以根据需要进行设置,本发明实施例对比不进行限制;所述相关度的计算可以采用现有技术,在此不再赘述。
此外,干扰特征集中还可以包含:每类干扰源对应的占用信道时间或者信号能量;可选的,所述接收设备还可以从预先存储的干扰特征集中选择N个不同干扰源对应的干扰特征向量作为所述干扰特征,具体如下:
接收设备从预先存储的干扰特征集中选择占用信道时间最长或者信号能量最高的N个不同干扰源对应的干扰特征向量作为所述干扰特征。
进一步的,所述处理器602可以可以基于下述(a)正交法、(b)矩阵求逆、(c)酉矩阵分解中的任一种方式根据所述信道特征和所述干扰特征获取所述干扰抵消矩阵:
(a)正交法
当采用正交法获得干扰抵消矩阵时,所述处理器602可以采用正交法计算出一个或多个干扰抵消向量,将所述干扰抵消向量组合成干扰抵消矩阵,具体如下:
获取与所述干扰特征中干扰特征向量相垂直的、且与所述信道特征夹角最小的一个或与所述信道特征夹角小于预设角度的特征向量作为所述干扰抵消向量。
其中,所述相垂直可以为近似接近于90度垂直或完全为90度垂直(理想状态下);所述预设角度可以根据需要进行设置,在此不再赘述。
(b)矩阵求逆
所述处理器602,具体用于:
将所述信道特征与所述干扰特征组合成第一联合矩阵;
对所述第一联合矩阵进行矩阵求逆运算,获得逆矩阵;
将所述逆矩阵中与所述信道特征对应的M个向量或将与所述信道特征对应的M个线性组合后的向量组合成所述干扰抵消矩阵。
其中,与所述信道特征对应的M个向量可以为:列(行)数序号与所述信道特征中需要抵消干扰的数据流对应的信道特征所处的行(列)数序号相等的向量;例如,需要抵消干扰的数据流的个数为M,且信道矩阵中需要抵消干扰的数据流对应第一联合矩阵的第2列和第3列,则将逆矩阵中的第2行和第3行的向量组合形成干扰抵消矩阵。
其中,所述线性组合可以为将与所述信道矩阵包含的向量乘以一个系数,所述系数是一个缩放因子,可将向量的幅度调整到一定的范围,避免引入过大定点化误差。
需要说明的是,当第一联合矩阵的行数、列数不相等时,或者第一联合矩阵不满秩时,对所述第一联合矩阵进行矩阵求逆运算可以为对第一联合矩阵求伪逆。
此外,为了避免求出的干扰抵消矩阵的幅度过大,本发明实施例中,处理器602还可以对第一联合矩阵进行多次近似求逆,从中选择一个满足要求的前M行向量作为所述干扰抵消矩阵,具体如下:
对所述第一联合矩阵进行至少一次近似求逆,获得至少一个近似逆矩阵;
分别利用所述至少一个近似逆矩阵中与所述信道特征对应的 M个向量计算所述第一信号的信噪比,获得至少一个信噪比;
将所述至少一个信噪比中,最大信噪比对应的M个向量或者将最大信噪比对应的M个线性组合后向量组合成所述干扰抵消矩阵。
例如:将干扰特征加入信道矩阵后面的列形成联合矩阵H′:
Figure PCTCN2015078597-appb-000013
需要说明的,本发明实施例中可以将干扰特征加入联合信道矩阵后面的列,也可以加入到联合信道矩阵前面的列;(H1i,H2i,…,HNri)是第i个数据流对应的信道特征,(IC1i,IC2i,…,ICNri)是第i个要干扰源的干扰特征。
然后,对H′求逆得到:
Figure PCTCN2015078597-appb-000014
若需要抵消前M个数据流中的干扰,则取逆矩阵H′-1中前M行向量作为干扰抵消矩阵C,以抵消M条数据流中的干扰,或者将逆矩阵H′-1中前M行向量与系数D相乘作为干扰抵消矩阵C:
Figure PCTCN2015078597-appb-000015
其中D是一个对角矩阵,是一个缩放因子,可将C的幅度调整到一定的范围,避免引入过大定点化误差。
另外,当H′矩阵的行数、列数不相等,或者H′矩阵不满秩时, 可以对H′L求伪逆。
此外,为避免干扰抵消矩阵幅度太大,对H′-1进行多次近似求逆,从中选择一个满足要求的干扰抵消矩阵,具体如下:
对H′-1矩阵进行至少一次近似求逆,获得至少一个近似逆矩阵H′-1
分别利用所述至少一个包含近似逆矩阵H′-1中前M行向量的干扰抵消矩阵计算接收到信号的信噪比;
将最大信噪比对应的干扰抵消矩阵作为干扰抵消矩阵C。
优选的,当接收到多条数据流时,可以根据下述公式计算信号的信噪比SNR:
Figure PCTCN2015078597-appb-000016
其中,diag表示对矩阵求对角线,x为发送信号,diag(C·H)·x为抵消干扰后的有用信号,non-diag(C·H)·x为有用信号之间的干扰;sumByRow表示按行求和,sumByRow(C·IC+C·BNG)为干扰源及噪声的干扰,BNG是系统中原有的每个天线接收到的背景噪声幅度。
(c)酉矩阵分解
处理器602,用于将所述处理器602估计出的信道特征与所述处理器602获取到的干扰特征组合成第二联合矩阵H′;
对所述第二联合矩阵进行酉矩阵分解,获得H′=U×S×V;其中,所述U和所述V为一个酉矩阵,所述S为一个对角矩阵;
收发器601,用于向发送设备发送所述处理器602分解出的V矩阵,以使得所述发送设备根据所述V矩阵设置预编码系数。
所述处理器602,具体用于:
将所述U矩阵与所述信道特征对应的M个向量组合的矩阵共轭转置后作为所述干扰抵消矩阵。
其中,与所述信道特征对应的M个向量可以为:列(行)数序号与所述信道特征中需要抵消干扰的数据流对应的信道特征所处的行(列)数序号相等的向量;酉矩阵分解可以为奇异值分解 (SVD)、几何平均值分解(GMD)等分解方式中的任一种分解方式。
例如:将干扰特征加入信道矩阵后面的列形成联合矩阵H′:
Figure PCTCN2015078597-appb-000017
需要说明的,本发明实施例中可以将干扰特征加入联合信道矩阵后面的列,也可以加入到联合信道矩阵前面的列;(H1i,H2i,…,HNri)是第i个数据流对应的信道特征,(IC1i,IC2i,…,ICNri)是第i个要干扰源的干扰特征。
然后,对H′进行酉矩阵分解,获得H′=U×S×V;其中,所述U和所述V为一个酉矩阵,所述S为一个对角矩阵;
向发送设备发送所述V矩阵,以使得发送设备根据V矩阵设置预编码系数;
若需要抵消前M个数据流中的干扰,则将所述U矩阵前M列向量组成的矩阵共轭转置后作为所述干扰抵消矩阵。
如此,接收设备可以利用获得的干扰抵消矩阵,抵消多条数据流中的干扰,提供数据传输的可靠性。
进一步的,为了避免在抵消信号中的干扰的同时,将信号中的有用数据消弱,本发明实施例中,所述处理器602,还用于:
在所述处理器602将所述干扰抵消矩阵与所述第一信号相乘之前,计算所述干扰矩阵中每个干扰特征向量与传输所述第一信号的信道的信道特征的每一行向量或列向量的相关度;
确定所述干扰矩阵的每个干扰特征向量与传输所述第一信号的信道的信道特征的每一行向量或列向量的相关度是否小于第二预设阈值;
所述处理器602,具体用于:
若确定小于第二预设阈值,则将所述干扰抵消矩阵与所述第 一信号相乘。
其中,第二预设阈值可以根据需要进行设置,本发明实施例对比不进行限制,所述相关度小于第二预设阈值,则表示该干扰源的干扰特征与所述信道矩阵不相关,在用干扰抵消向量抵消信号中干扰的同时不会明显消弱有用信号的强度;
所述相关度大于等于第二预设阈值,则表示该干扰源的干扰特征与所述信道矩阵相关,在用干扰抵消向量抵消信号中干扰的同时也会消弱信号中有用信号的强度,不可用所述干扰抵消矩阵与所述第一信号相乘。
通常情况下,在每个接收周期内接收到第一部分信号时,需要对传输信号的信道进行空闲信道评估(Clear Channel Assessment,CCA),若信道为忙信道,则对接收到的第一部分信号进行解调,获得用于估计信道特征和判断信号是否为有用信号的SIG;若信道为闲信道,则不做任何处理;
然而,在某种情况下,在发送设备没有发送信号的情况下,接收设备接收到干扰且接收能量大于阈值(相当于信道被干扰完全所占用),则接收设备会误认为信道繁忙,为了避免接收设备将被干扰所占用的信道误认为发送设备正在传输信号的忙信道,本发明实施例中,所述处理器602,还用于:
在所述处理器602根据所述第二信号估计发送所述第二信号的信道特征之前,用预先存储的第一干扰抵消向量接收所述第二信号,以抵消所述第二信号中的干扰;
确定接收到的所述第二信号的信号能量是否大于等于第三预设阈值;
所述处理器602,具体用于:
若大于等于所述第三预设阈值,则确定信道忙,根据所述第二信号估计发送所述第二信号的信道特征;
若确定抵消干扰后的第一信号的信号能量小于第三预设阈值,则确定信道闲,可以利用信道向发送设备发送数据。
由上可知,本发明实施例提供一种接收设备,接收到第一信号后,用获取的干扰抵消矩阵与所述第一信号相乘,并将相乘后的信号解调获得M条数据流,以抵消M条数据流中的干扰,使得解调后获得数据为抵消干扰后的数据,大大提高了数据传输的可靠性。
所属领域的技术人员可以清楚地了解到,为描述的方便和简洁,上述描述的系统,装置和单元的具体工作过程,可以参考前述方法实施例中的对应过程,在此不再赘述。
在本申请所提供的几个实施例中,应该理解到,所揭露的系统,装置和方法,可以通过其它的方式实现。例如,以上所描述的装置实施例仅仅是示意性的,例如,所述单元的划分,仅仅为一种逻辑功能划分,实际实现时可以有另外的划分方式,例如多个单元或组件可以结合或者可以集成到另一个系统,或一些特征可以忽略,或不执行。另一点,所显示或讨论的相互之间的耦合或直接耦合或通信连接可以是通过一些接口,装置或单元的间接耦合或通信连接,可以是电性或其它的形式。
所述作为分离部件说明的单元可以是或者也可以不是物理上分开的,作为单元显示的部件可以是或者也可以不是物理单元,即可以位于一个地方,或者也可以分布到多个网络单元上。可以根据实际的需要选择其中的部分或者全部单元来实现本实施例方案的目的。
另外,在本发明各个实施例中的各功能单元可以集成在一个处理单元中,也可以是各个单元单独物理包括,也可以两个或两个以上单元集成在一个单元中。上述集成的单元既可以采用硬件的形式实现,也可以采用硬件加软件功能单元的形式实现。
上述以软件功能单元的形式实现的集成的单元,可以存储在一个计算机可读取存储介质中。上述软件功能单元存储在一个存储介质中,包括若干指令用以使得一台计算机设备(可以是个人计算机,服务器,或者网络设备等)执行本发明各个实施例所述方法的 部分步骤。而前述的存储介质包括:U盘、移动硬盘、只读存储器(Read-Only Memory,简称ROM)、随机存取存储器(Random Access Memory,简称RAM)、磁碟或者光盘等各种可以存储程序代码的介质。
最后应说明的是:以上实施例仅用以说明本发明的技术方案,而非对其限制;尽管参照前述实施例对本发明进行了详细的说明,本领域的普通技术人员应当理解:其依然可以对前述各实施例所记载的技术方案进行修改,或者对其中部分技术特征进行等同替换;而这些修改或者替换,并不使相应技术方案的本质脱离本发明各实施例技术方案的精神和范围。

Claims (24)

  1. 一种干扰抵消方法,其特征在于,应用于接收设备,其中,所述接收设备配置有Nr个接收天线,用于接收Nt个发送天线或空间流或空间时间流输出的信号,所述Nr为大于等于2的整数,所述Nt为大于等于1的整数;所述方法包括:
    接收第一信号;其中,所述第一信号包含Nr个接收天线接收到的Nt个发送天线或空间流或空间时间流输出的信号经过信道后的信号和噪声信号;
    获取干扰抵消矩阵;所述干扰抵消矩阵包含M个干扰抵消向量,每个干扰抵消向量包含Nr个干扰抵消系数,所述每个干扰抵消向量与N个干扰源中任一个干扰源在Nr个接收天线上的干扰特征向量的相关度小于第一预设阈值;所述M为预先设置的干扰抵消向量的个数;所述N为预先设置的干扰的个数;
    将所述干扰抵消矩阵与所述第一信号相乘,并将相乘后的信号解调获得数据流。
  2. 根据权利要求1所述的干扰抵消方法,其特征在于,所述获取干扰抵消矩阵包括:
    在第一接收周期内接收第二信号,其中,所述第二信号为Nr个接收天线接收到的信号;
    根据所述第二信号估计传输所述第二信号的信道的信道特征;其中,所述信道特征为Nr乘Nt的矩阵;
    获取干扰特征,其中,所述干扰特征由N个向量组成,第i个向量为第i个干扰源在所述Nr个接收天线上的干扰特征向量;
    根据所述信道特征和所述干扰特征获取所述干扰抵消矩阵。
  3. 根据权利要求2所述的干扰抵消方法,其特征在于,对于所述干扰抵消矩阵中的任一干扰抵消向量,所述根据所述信道特征和所述干扰特征获取干扰抵消向量包括:
    获取与所述干扰特征中干扰特征向量相垂直的、且与所述信道特征夹角最小的一个或与所述信道特征夹角小于预设角度的特征向量 作为所述干扰抵消向量。
  4. 根据权利要求2所述的干扰抵消方法,其特征在于,所述根据所述信道特征和所述干扰特征获取干扰抵消矩阵包括:
    将所述信道特征与所述干扰特征组合成第一联合矩阵;
    对所述第一联合矩阵进行矩阵求逆运算,获得逆矩阵;
    将所述逆矩阵中与所述信道特征对应的M个向量或将与所述信道特征对应的M个线性组合后的向量组合成所述干扰抵消矩阵。
  5. 根据权利要求4所述的干扰抵消方法,其特征在于,对所述第一联合矩阵进行矩阵求逆运算,获得逆矩阵包括:
    对所述第一联合矩阵进行至少一次近似求逆,获得至少一个近似逆矩阵;
    所述将所述逆矩阵中与所述信道特征对应的M个向量或将与所述信道特征对应的M个线性组合后的向量组合成所述干扰抵消矩阵包括:
    分别利用所述至少一个近似逆矩阵中与所述信道特征对应的M个向量计算所述第一信号的信噪比,获得至少一个信噪比;
    将所述至少一个信噪比中,最大信噪比对应的M个向量或者将最大信噪比对应的M个线性组合后向量组合成所述干扰抵消矩阵。
  6. 根据权利要求2所述的干扰抵消方法,其特征在于,在根据所述信道特征和所述干扰特征获取干扰抵消矩阵之前,所述方法还包括:
    将所述信道特征与所述干扰特征组合成第二联合矩阵H′;
    对所述第二联合矩阵进行酉矩阵分解,获得H′=U×S×V;其中,所述U和所述V为一个酉矩阵,所述S为一个对角矩阵;
    向发送设备发送所述V矩阵,以使得所述发送设备根据所述V矩阵设置预编码系数。
  7. 根据权利要求6所述的干扰抵消方法,其特征在于,所述根据所述信道特征和所述干扰特征获取干扰抵消矩阵包括:
    将所述U矩阵中与所述信道特征对应的M个向量组成的矩阵共 轭转置后作为所述干扰抵消矩阵。
  8. 根据权利要求2-7任一项所述的干扰抵消方法,其特征在于,对于所述干扰特征中的任一个干扰特征向量,在所述获取所述干扰特征向量之前,所述方法还包括:
    在第二接收周期内接收第三信号;
    若确定所述第三信号为干扰信号,则记录所述第三信号在Nr个接收天线上的干扰特征向量;
    所述获取所述干扰特征向量包括:
    将所述第三信号在Nr个接收天线上的干扰特征向量作为所述干扰特征向量;或
    所述获取所述干扰特征向量包括:
    对所述第三信号在Nr个接收天线上的干扰特征向量与其他至少一个接收周期接收到的干扰信号在Nr个接收天线上的干扰特征向量进行加权求和;
    将加权求和后的结果记录为所述第三信号在Nr个接收天线上的干扰特征向量。
  9. 根据权利要求8所述的干扰抵消方法,其特征在于,所述确定所述第三信号为干扰信号包括:
    对所述第三信号进行解调,若解调出的数据帧的至少一个域与预设干扰源的域相同,则确定所述第三信号为干扰信号。
  10. 根据权利要求8所述的干扰抵消方法,其特征在于,所述确定所述第三信号为干扰信号包括:
    解调所述第三信号对应的域消息SIG;其中,所述SIG包括:数据流信息和校验字段;
    根据预设算法计算第一校验字段,若所述第一校验字段与所述SIG中包含的校验字段不同,则确定所述第三信号为干扰信号;
    或者,若所述数据流信息的数据格式与预设数据格式不同,则确定所述第三信号为干扰信号。
  11. 根据权利要求2-10任一项所述的干扰抵消方法,其特征在 于,在将所述干扰抵消矩阵与所述第一信号相乘之前,所述方法还包括:
    计算所述干扰矩阵中每个干扰特征向量与传输所述第一信号的信道的信道特征的每一行向量或列向量的相关度;
    确定所述干扰矩阵的每个干扰特征向量与传输所述第一信号的信道的信道特征的每一行向量或列向量的相关度是否小于第二预设阈值;
    所述将所述干扰抵消矩阵与所述第一信号相乘具体包括:
    若确定小于第二预设阈值,则将所述干扰抵消矩阵与所述第一信号相乘。
  12. 根据权利要求11所述的干扰抵消方法,其特征在于,在根据所述第二信号估计发送所述第二信号的信道特征之前,所述方法还包括:
    用预先存储的第一干扰抵消向量接收所述第二信号,以抵消所述第二信号中的干扰;
    确定接收到的所述第二信号的信号能量是否大于等于第三预设阈值;
    所述根据所述第二信号估计发送所述第二信号的信道特征具体包括:
    若大于等于所述第三预设阈值,则根据所述第二信号估计发送所述第二信号的信道特征。
  13. 一种接收设备,所述接收设备配置有Nr个接收天线,用于接收Nt个发送天线或空间流或空间时间流输出的信号,所述Nt为大于等于2的整数,所述Nt为大于等于1的整数;其特征在于,包括:
    接收单元,用于接收第一信号;其中,所述第一信号包含Nr个接收天线接收到的Nt个发送天线或空间流或空间时间流输出的信号经过信道后的信号和噪声信号;
    获取单元,用于获取干扰抵消矩阵;所述干扰抵消矩阵包含M个干扰抵消向量,每个干扰抵消向量包含Nr个干扰抵消系数,所述 每个干扰抵消向量与N个干扰源中任一个干扰源在Nr个接收天线上的干扰特征向量的相关度小于第一预设阈值;所述M为预先设置的干扰抵消向量的个数;所述N为预先设置的干扰的个数;
    干扰抵消单元,用于将所述干扰抵消矩阵与所述第一信号相乘,并将相乘后的信号解调获得数据流。
  14. 根据权利要求13所述的接收设备,其特征在于,
    所述接收单元,还用于在第一接收周期内接收第二信号,其中,所述第二信号为Nr个接收天线接收到的信号;
    所述接收设备还包括:
    信道估计单元,用于根据所述接收单元接收到的第二信号估计传输所述第二信号的信道的信道特征;其中,所述信道特征为Nr乘Nt的矩阵;
    所述获取单元,具体用于:
    获取干扰特征,其中,所述干扰特征由N个向量组成,第i个向量为第i个干扰源在所述Nr个接收天线上的干扰特征向量;
    并根据所述信道估计单元估计出的信道特征和获取到的所述干扰特征获取干扰抵消矩阵。
  15. 根据权利要求14所述的接收设备,对于所述干扰抵消矩阵中的任一干扰抵消向量,其特征在于,所述获取单元,具体用于:
    获取与所述干扰特征中干扰特征向量相垂直的、且与所述信道特征夹角最小的一个或与所述信道特征夹角小于预设角度的特征向量作为所述干扰抵消向量。
  16. 根据权利要求14所述的接收设备,其特征在于,所述获取单元,具体用于:
    将所述信道特征与所述干扰特征组合成第一联合矩阵;
    对所述第一联合矩阵进行矩阵求逆运算,获得逆矩阵;
    将所述逆矩阵中与所述信道特征对应的M个向量或将与所述信道特征对应的M个线性组合后的向量组合成所述干扰抵消矩阵。
  17. 根据权利要求16所述的接收设备,其特征在于,所述获取 单元,具体用于:
    对所述第一联合矩阵进行至少一次近似求逆,获得至少一个近似逆矩阵;
    分别利用所述至少一个近似逆矩阵中与所述信道特征对应的M个向量计算所述第一信号的信噪比,获得至少一个信噪比;
    将所述至少一个信噪比中,最大信噪比对应的M个向量或者将最大信噪比对应的M个线性组合后向量组合成所述干扰抵消矩阵。
  18. 根据权利要求14所述的接收设备,其特征在于,所述接收设备还包括:
    分解单元,用于在所述获取单元根据所述信道特征和所述干扰特征获取干扰抵消矩阵之前,将所述信道估计单元估计出的信道特征与所述获取单元获取到的干扰特征组合成第二联合矩阵H′;
    对所述第二联合矩阵进行酉矩阵分解,获得H′=U×S×V;其中,所述U和所述V为一个酉矩阵,所述S为一个对角矩阵;
    发送单元,用于向发送设备发送所述分解单元分解出的V矩阵,以使得所述发送设备根据所述V矩阵设置预编码系数。
  19. 根据权利要求18所述的接收设备,其特征在于,所述获取单元,具体用于:
    将所述U矩阵中与所述信道特征对应的M个向量组成的矩阵共轭转置后作为所述干扰抵消矩阵。
  20. 根据权利要求14-19任一项所述的接收设备,其特征在于,对于所述干扰特征中的任一个干扰特征向量,在所述获取单元获取所述干扰特征向量之前,
    所述接收单元,还用于在第二接收周期内接收第三信号;
    所述获取单元,还用于若确定所述接收单元接收到的所述第三信号为干扰信号,则记录所述第三信号在Nr个接收天线上的干扰特征向量;
    将所述第三信号在Nr个接收天线上的干扰特征向量作为所述干扰特征;或
    对所述第三信号在Nr个接收天线上的干扰特征向量与其他至少一个接收周期接收到的干扰信号在Nr个接收天线上的干扰特征向量进行加权求和;
    将加权求和后的结果记录为所述第三信号在Nr个接收天线上的干扰特征向量。
  21. 根据权利要求20所述的接收设备,其特征在于,所述获取单元,具体用于:
    对所述第三信号进行解调,若解调出的数据帧的至少一个域与预设干扰源的域相同,则确定所述第三信号为干扰信号。
  22. 根据权利要求20所述的接收设备,其特征在于,所述获取单元,具体用于:
    解调所述第三信号对应的域消息SIG;其中,所述SIG包括:数据流信息和校验字段;
    根据预设算法计算第一校验字段,若所述第一校验字段与所述SIG中包含的校验字段不同,则确定所述第三信号为干扰信号;
    或者,若所述数据流信息的数据格式与预设数据格式不同,则确定所述第三信号为干扰信号。
  23. 根据权利要求14-22任一项所述的接收设备,其特征在于,所述接收设备还包括:
    计算单元,用于在所述干扰抵消单元将所述干扰抵消矩阵与所述第一信号相乘之前,计算所述干扰矩阵中每个干扰特征向量与传输所述第一信号的信道的信道特征的每一行向量或列向量的相关度;
    确定所述干扰矩阵的每个干扰特征向量与传输所述第一信号的信道的信道特征的每一行向量或列向量的相关度是否小于第二预设阈值;
    所述干扰抵消单元,具体用于:
    若确定小于第二预设阈值,则将所述干扰抵消矩阵与所述第一信号相乘。
  24. 根据权利要求23所述的接收设备,其特征在于,所述干扰 抵消单元,还用于:
    在所述信道估计单元根据所述第二信号估计发送所述第二信号的信道特征之前,用预先存储的第一干扰抵消向量接收所述第二信号,以抵消所述第二信号中的干扰;
    确定接收到的所述第二信号的信号能量是否大于等于第三预设阈值;
    所述信道估计单元,具体用于:
    若大于等于所述第三预设阈值,则根据所述第二信号估计发送所述第二信号的信道特征。
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