JP2021150707A - Receiver, transmitter, communication method, and program - Google Patents

Abstract

To suppress influence of interference caused by terminal-to-terminal communication.SOLUTION: A receiver for receiving a signal transmitted from a transmitter sets a blank frame containing no data in frames during communication with the transmitter; estimates a channel of a signal of another system in a period corresponding to the blank frame; on the basis of the channel, removes an interference component from the other system contained in the received signal; and, on the basis of the signal from which the interference component is removed, demodulates data transmitted from the transmitter.SELECTED DRAWING: Figure 7

Description

The present invention relates to a wireless communication channel estimation technique.

The applications of wireless communication have diversified, and wireless communication functions have come to be used in various systems. On the other hand, frequency resources are limited, and it is assumed that multiple systems share a frequency band. When multiple wireless systems share a common frequency band, the wireless signals between these systems can interfere. Non-Patent Document 1 describes a method of removing interference components between signal components by sequentially separating the signal components.

G. J. Foschini, "Layered space-time architecture for wireless communication in a fading environment when using multi-element antennas", Bell Labs Tech. J., pp. 41-59, August 1996

Interference elimination can generate an accurate replica of the interference signal by obtaining sufficient channel estimation accuracy. Here, in the same system, for example, by arranging the reference signals for channel estimation so as not to interfere with each other, highly accurate channel estimation can be performed. On the other hand, it is difficult to arrange reference signals between different systems so as not to interfere with each other, and it is not possible to improve the channel estimation accuracy.

The present invention provides a technique for improving channel estimation accuracy in a frequency sharing system.

The receiving device according to one aspect of the present invention is a receiving device that receives a signal transmitted from the transmitting device, and receives data in a frame during communication between the receiving means for receiving the signal and the transmitting device. It is included in the signal received by the receiving means based on the setting means for setting the blank frame not included, the estimating means for estimating the channel of the signal of the other system in the period corresponding to the blank frame, and the channel. It has a removing means for removing an interfering component from the other system, and a demodulating means for demodulating the data transmitted from the transmitting device based on the signal from which the interfering component has been removed.

The transmitting device according to one aspect of the present invention is a transmitting device that transmits a signal to the receiving device, and is used by the receiving device to estimate a channel for a signal from another system to be removed in the receiving device. , A setting means for setting a blank frame that does not include data in a frame being communicated with the receiving device, and a signal to the receiving device in a frame other than the blank frame without transmitting a signal in the blank frame. Has a transmission means for transmitting the data.

According to the present invention, the channel estimation accuracy can be improved in the frequency sharing system.

It is a figure which shows the system configuration example. It is a figure explaining the setting of a blank frame. It is a figure which shows the hardware configuration example of each apparatus. It is a figure which shows the functional configuration example of a transmission device. It is a figure which shows the functional configuration example of a receiving device. It is a figure which shows the example of the flow of processing executed by a transmission device. It is a figure which shows the example of the flow of processing executed by a receiving device.

Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. The following embodiments do not limit the invention according to the claims, and not all combinations of features described in the embodiments are essential to the invention. Two or more of the features described in the embodiments may be arbitrarily combined. In addition, the same or similar configuration will be given the same reference number, and duplicated explanations will be omitted.

(System configuration)
FIG. 1 shows a configuration example of a wireless communication system according to the present embodiment. In one example, the wireless communication system includes a cellular communication system. The cellular communication system is an arbitrary generation cellular communication system such as a 5th generation (5G) system or a long-term evolution (LTE) system, and is configured to include a base station device 101 and a terminal device 102. NS. In this system, the cellular communication system shall share the same frequency as other systems. Here, the other system may be, for example, a system different from the cellular communication system such as a fixed wireless access system, or for example, another cellular communication with a different management entity from the cellular communication system including the base station apparatus 101. It may be a system.

In wireless communication systems in which frequency resources are shared, interference between systems becomes a problem. For example, FIG. 1 shows that the signal transmitted by the transmitting device 111 of the other system A to the receiving device 112 of the other system A can interfere with the signal transmitted by the base station device 101 to the terminal device 102. .. Similarly, FIG. 1 shows that the signal transmitted by the transmitting device 121 of the other system B to the receiving device 122 of the other system B can interfere with the signal transmitted by the terminal device 102 to the base station device 101. There is.

In a system in which such interference occurs, as an example, by removing the interference component from the signal using an interference canceller, the performance at the time of demodulation / decoding of the desired signal can be improved. For example, according to the sequential interference canceller (SIC), first, demodulation / demodulation of the interference signal component is executed on the received signal, and the resulting data is encoded / modulated again, and the obtained modulated signal is obtained. Is multiplied by the channel estimate to generate a replica of the interference signal. Then, the replica of the interference signal is subtracted from the received signal, so that the interference signal component is removed from the received signal. The desired signal component is removed by executing demodulation / decoding of the desired signal from the signal from which the interference signal component has been removed, generating a replica of the desired signal based on the result, and subtracting it from the received signal. Signal can be obtained. Then, based on the signal from which the desired signal component has been removed, it is possible to perform demodulation / decoding of the interference signal and replica generation to generate a replica of the interference signal with higher accuracy. For example, when the data to be transmitted is encoded by a turbo code, a convolutional code, or the like, the demodulation / decoding accuracy of the desired signal and the interference signal can be improved by repeating these processes.

On the other hand, in order for the interference canceller to exhibit a sufficient interference suppression function, it is required that highly accurate channel estimation is possible. Here, when the interference signals received by the base station device 101 and the terminal device 102 are signals from the same system, for example, the radio resources (time / frequency resources) to which the reference signal should be transmitted are adjusted in the system. can do. However, when the interference signal received by the base station device 101 or the terminal device 102 is a signal from another system, such adjustment cannot be performed. Therefore, it is not possible to perform channel estimation for signals from other systems with high accuracy.

In this embodiment, in view of such circumstances, data is generated in a frame in which the transmitting side device (transmitting device) of the base station device 101 and the terminal device 102 is communicating with the receiving side device (receiving device). Set a blank frame that does not include. Note that "during communication" here refers to a state in which a data frame including user data can be transmitted / received between the base station device 101 and the terminal device 102 at any time. For example, when the first frame to which the radio resource is allocated for the communication between the base station device 101 and the terminal device 102 is a blank frame, it is said that the communication is not actually performed but is in progress. Also, the blank frame may contain at least no data, while may include, for example, a control channel or a reference signal. That is, a no-signal period may be set that does not include the control channel and the reference signal, or the minimum information for communication control may be transmitted. In addition, "frame" may be read as "subframe".

When the blank frame is set in this way, the receiving device receives only the interference signal component in the period corresponding to the blank frame. The receiving device shares the setting of which frame is set as the blank frame by communicating the control signal for setting the blank frame with, for example, the transmitting device. For example, the base station apparatus 101 sets a blank frame and notifies the terminal apparatus 102 of the setting. The terminal device 102 may set a blank frame and notify the base station device 101 of the setting. The transmitting device prevents the data from being transmitted in the blank frame according to its shared setting, and the receiving device performs channel estimation of the interfering signal in the blank frame according to its shared setting. In the blank frame, for example, functions other than channel estimation of the interference signal are turned off. That is, each process for receiving the desired signal and the process for generating the replica of the interference signal, excluding the channel estimation, are not executed. The receiving device can perform channel estimation of the interfering signal with high accuracy based on the received interfering signal. The receiving device can acquire information such as the arrangement of the reference signal regarding the interference signal in advance. For example, when the receiving device is the base station device 101, the information can be acquired from, for example, a network node that exchanges system information with another system. Further, when the receiving device is the terminal device 102, the information may be acquired by signaling from the base station device 101 (for example, by at least one of a broadcast signal and an individual signal).

The blank frame is set to have a length of two or more frames of the long method of the frame of the desired signal and the frame of the interference signal. As a result, the interference signal for at least one frame can be received in the absence of the desired signal, and the channel estimation accuracy of the interference signal can be improved. For example, as shown in FIG. 2A, for example, when the frame length of the interference signal is longer than the frame length of the desired signal, the number of frames of the desired signal corresponding to the length of two frames or more of the interference signal is displayed. Set as a blank frame. Further, as shown in FIG. 2B, when the frame length of the desired signal is longer than the frame length of the interference signal, two frames of the desired signal are set as blank frames. As shown in FIGS. 2A and 2B, the blank frame is set in a plurality of consecutive frames. Note that FIGS. 2 (A) and 2 (B) show an example in which the number of frames to be set as blank frames is determined based on the two frames having the longer frame length, for example. A larger number, such as 3 frames, may be used as blank frames.

Further, the necessity of generating a blank frame can be determined based on, for example, the radio quality in the receiving device. For example, a blank frame can be generated when the signal-to-noise and interference power ratio of the desired signal in the receiving device is below a predetermined value. Further, for example, when the reception success rate of the desired signal (the ratio of the number of times the desired signal is successfully received to the number of times the signal is received) in the receiving device falls below a predetermined value, the removal of the interference signal is sufficiently effective. Since there is a possibility that there is no such thing, a blank frame can be set to estimate the channel of the interference signal. This makes it possible to perform channel estimation of the interference signal with high accuracy. The receiving device uses, for example, a cyclic redundancy check (CRC) to determine whether the signal after demodulation / decoding has an error, and if there is no error, it is determined that the reception is successful. In this case, either the transmitting device or the receiving device may decide whether or not to generate a blank frame. For example, when the base station device 101 operates as a receiving device (that is, when communicating on an uplink), the base station device 101 identifies a reception success rate for a signal transmitted from a terminal device 102 operating as a transmitting device, and the terminal It may be possible to decide whether to have the device 102 set a blank frame. Further, when the base station device 101 operates as a transmitting device (that is, when communicating on a downlink), the base station device 101 counts the number of HARQ (composite automatic repeat requests) retransmission requests in the terminal device 102 operating as a receiving device. By specifying the number of successful receptions, or by specifying whether or not the HARQ ACK from the terminal device 102 has been received, the reception success rate is specified, and a blank frame is set in the signal transmitted to the terminal device 102. You can decide whether to set it.

When the transmitting device transmits a signal to each of a plurality of receiving devices, a blank frame is set based on the number of receiving devices that have succeeded in receiving the signal among the plurality of receiving devices. It can be determined whether or not to do so. For example, it is determined to set a blank frame when the ratio of the number of receiving devices that have succeeded in receiving the signal to the number of receiving devices to which the signal is transmitted is less than a predetermined value. For example, when the base station device 101 operating as a transmitting device transmits a signal to a plurality of terminal devices 102 on a downlink and the reception success rate is low according to the number of terminal devices 102 that have succeeded in receiving the signal. It can be decided to set a blank frame. The base station device 101 can specify whether or not each of the plurality of terminal devices 102 has succeeded in receiving, for example, by a HARQ retransmission request or ACK from the plurality of terminal devices 102. The base station device 101 may decide to set a blank frame, for example, when the number of the terminal devices 102 that have transmitted the retransmission request exceeds a predetermined number among the plurality of terminal devices 102.

Hereinafter, the configurations of the transmitting device and the receiving device that execute such processing and an example of the processing flow will be described.

(Device configuration)
FIG. 3 shows a hardware configuration example of the communication device (base station device 101 or terminal device 102) according to the present embodiment. In one example, the communication device includes a processor 301, a ROM 302, a RAM 303, a storage device 304, and a communication circuit 305. The processor 301 is a computer including one or more processing circuits such as a general-purpose CPU (central processing unit) and an ASIC (integrated circuit for a specific application), and is stored in a ROM 302 or a storage device 304. By reading and executing the existing program, the entire processing of the communication device and each of the above-mentioned processing are executed. The ROM 302 is a read-only memory that stores information such as programs and various parameters related to processing executed by the communication device. The RAM 303 is a random access memory that functions as a workspace when the processor 301 executes a program and stores temporary information. The storage device 304 is composed of, for example, a detachable external storage device or the like. The communication circuit 305 includes a circuit for wireless communication. Although one communication circuit 305 is shown in FIG. 3, the communication device may have a plurality of communication circuits.

FIG. 4 shows an example of the functional configuration of the transmitter. The transmission device includes, for example, a modulation coding unit 401, a frame control unit 402, a blank frame control unit 403, a blank frame setting unit 404, and an RF unit 405. These functions can be realized, for example, by the processor incorporated in the communication circuit 305 executing a predetermined program. It should be noted that some of these functions may be realized, for example, by the processor 301 executing a program stored in the ROM 302 or the like. Further, FIG. 4 conceptually shows the functions of the transmission device, and it is not necessary to divide the functions as shown in FIG. The transmitting device is mounted on both the base station device 101 and the terminal device 102, for example.

The modulation coding unit 401 performs error correction coding of the transmission data series, modulates the coded bit string, and outputs the coded bit string. The frame control unit 402 acquires the modulated symbol sequence, maps the symbol sequence within the frame, and generates a transmission target frame for transmitting the transmission data series. The blank frame control unit 403 executes control for setting a predetermined timing and number of frames as blank frames in the frames during communication with the receiving device. For example, the blank frame control unit 403 outputs the frame number of the frame to be a blank frame to the frame control unit 402, and the frame control unit 402 describes the no-signal period, the control signal, and the reference for the frame of the frame number. By transmitting only the signal, a blank frame containing no data is output. That is, the frame control unit 402 does not map the output symbol sequence of the modulation coding unit 401 in the blank frame. The blank frame setting unit 404 determines whether or not to generate a blank frame, sets the timing and length of the blank frame, and the like. If it is agreed in advance that a blank frame is set periodically, the blank frame setting unit 404 may be omitted. As described above, the blank frame setting unit 404 determines whether or not to generate a blank frame based on, for example, radio quality. Further, the blank frame setting unit 404 uses FIGS. 2A and 2B based on, for example, the frame length of the interference signal from another system and the frame length of the frame transmitted by the own device. As described, the period of blank frames can be determined. The blank frame setting unit 404 shares the determined setting with the receiving device. The blank frame setting unit 404 may receive the setting from the receiving device and pass it to the blank frame control unit 403. The RF unit 405 executes various processes executed by a general transmitter on the generated frame, converts it into an RF signal format, and transmits the RF signal.

FIG. 5 shows an example of the functional configuration of the receiving device. The receiving device includes, for example, an RF unit 501, a local system signal processing unit 511, another system signal processing unit 521, a blank frame control unit 531 and a blank frame setting unit 532. The own system signal processing unit 511 includes a demodulation unit 512, a channel estimation unit 513, and a decoding unit 514. The other system signal processing unit 521 includes a demodulation unit 522, a channel estimation unit 523, a decoding unit 524, and a replica generation unit 525. These functions can be realized, for example, by the processor incorporated in the communication circuit 305 executing a predetermined program. It should be noted that some of these functions may be realized, for example, by the processor 301 executing a program stored in the ROM 302 or the like. Further, FIG. 5 conceptually shows the functions of the receiving device, and it is not necessary to divide the functions as shown in FIG. The receiving device is mounted on both the base station device 101 and the terminal device 102, for example.

The RF unit 501 executes various processes executed by a general transmitter on the received RF signal, and outputs, for example, a baseband waveform. This waveform is input to, for example, another system signal processing unit 521 and the adder 502 (via, for example, a delayer). The demodulation unit 522 of the other system signal processing unit 521 demodulates the interference signal based on the input waveform. This demodulation is performed using the channel estimates estimated by the channel estimation unit 523. As the demodulation method using the channel estimated value, for example, a method of dividing the value indicating the waveform by the channel estimated value may be used, or a general method known to those skilled in the art may be used. The channel estimation unit 523 estimates the channel of the interference signal. For example, the channel estimation unit 523 grasps in advance the time / frequency position where the reference signal of the signal of another system exists, and estimates the channel of the interference signal based on the value of the received signal at that position. In the present embodiment, the channel estimation unit 523 may, for example, perform channel estimation of the interference signal only during the blank frame period. As a result, a highly accurate channel estimate can be obtained, and the accuracy of demodulation by the demodulation unit 522 can also be improved. In this case, the channel estimation unit 523 may hold the channel estimation value estimated during the immediately preceding blank frame until the channel is estimated in the next blank claim. As a result, it is possible to prevent the accuracy of the channel estimation value from being deteriorated by performing the channel estimation during a period other than the blank frame. The bit string obtained by demodulation by the demodulation unit 522 is input to the decoding unit 524, and error correction decoding is executed for the bit string. The decoding result of the decoding unit 524 is input to the replica generation unit 525. The replica generation unit 525 error-corrects and encodes the bit string obtained as a result of decoding using the same coding method used by the transmission device, and modulates the error-correction-encoded sequence. Then, the replica generation unit 525 generates a replica of the interference signal by multiplying the modulated symbol sequence by the channel estimation value estimated by the channel estimation unit 523. The generated replica is input to the adder 502.

In the adder 502, the received signal with the same timing and the replica of the interference signal are input, and the waveform resulting from the subtraction of the interference signal from the reception signal is output. The demodulation unit 512 executes demodulation processing on this waveform. In this demodulation process, the channel estimation value estimated by the channel estimation unit 513 is used. The channel estimation unit 513 extracts the waveform obtained by subtracting the interference signal from the received signal at the position of the time and frequency at which the reference signal of the desired signal is transmitted, and acquires the channel estimation value. At this time, if the replica signal generated by the replica generation unit 525 has high accuracy, the interference signal component is removed with high accuracy, so that channel estimation can be performed with high accuracy, and the demodulation accuracy in the demodulation unit 512 is also high. Can be improved. Finally, the bit string obtained by the demodulation by the demodulation unit 512 is input to the decoding unit 514, error correction decoding is performed, and the data of the desired signal is extracted. A CRC check or the like is executed on the decrypted data, and a HARQ retransmission request or an ACK transmission is performed as necessary.

The blank frame control unit 531 makes only the channel estimation unit 523 of the other system signal processing unit 521 operate in the frame set as the blank frame by the transmitting device, so that the own system signal processing unit 511 and the other system signal processing unit 521 operate. Control is performed so that the functional units other than the channel estimation unit 523 of the above do not operate. As a result, the channel estimation accuracy of the interference signal by the channel estimation unit 523 can be improved.

The blank frame setting unit 532 determines whether or not to generate a blank frame in the transmission device, sets the timing and length of the blank frame, and the like. If it is agreed in advance that a blank frame is set periodically, the blank frame setting unit 532 may be omitted. As described above, the blank frame setting unit 532 determines whether or not to cause the transmitter to generate a blank frame based on, for example, radio quality. Further, the blank frame setting unit 532 uses FIGS. 2A and 2B based on, for example, the frame length of the interference signal from another system and the frame length of the frame received by the own device. As described, the period of blank frames can be determined. The blank frame setting unit 532 shares the determined setting with the transmitting device. The blank frame setting unit 532 may receive the setting from the transmission device and pass it to the blank frame control unit 531.

(Processing flow)
An example of a processing flow executed by the transmitting device will be outlined with reference to FIG. Since the details of each process are as described above, the description will not be repeated here.

First, the transmitting device executes the setting of the blank frame (S601). For example, by communicating information about the settings with the receiving device, the common settings are recognized by the transmitting device and the receiving device. If the setting is determined in advance, the process of S601 may be omitted. Further, in the example of FIG. 6, an example is shown in which the process of S601 is not executed once the setting is made, but this setting may be executed periodically, for example. The transmitting device determines whether the frame to be transmitted is set as a blank frame when communicating with the receiving device (S602). The transmitting device generates a blank frame containing no user data (S603) for a frame set as a blank frame (YES in S602), and NO for a frame not set as a blank frame (NO in S602). ), A data frame including user data is generated (S604). Then, the transmitting device transmits the generated frame (S605). After that, the transmitting device can repeatedly execute the same process until, for example, the connection with the receiving device is disconnected.

Subsequently, with reference to FIG. 7, an example of a processing flow executed by the receiving device will be outlined. Since the details of each process are as described above, the description will not be repeated here.

First, the receiving device executes the setting of the blank frame (S701). For example, by communicating information about the settings with the transmitting device, the common settings are recognized by the transmitting device and the receiving device. If the setting is determined in advance, the process of S701 may be omitted. Further, in the example of FIG. 7, an example is shown in which the process of S701 is not executed once the setting is made, but this setting may be executed periodically, for example.

The receiving device determines whether or not the currently received frame is a frame set as a blank frame with respect to the received wireless signal, for example, based on the frame number of the desired signal (S702). Then, the receiving device executes channel estimation of the interference signal during the period when the frame is a blank frame (YES in S702) (S703). On the other hand, in the period other than the blank frame, the receiving device executes demodulation / decoding of the interference signal based on the channel estimated value estimated in S703 (S704), and interferes using the result and the channel estimated value. Generate a replica of the signal (S705). Then, the receiving device subtracts the generated replica signal from the received signal (S706), and demodulates / decodes the desired signal from the subtracted signal (S707).

In this embodiment, an example in which the interference signal is demodulated / decoded first is shown, but the present invention is not limited to this. For example, the powers of the desired signal and the interference signal may be compared, and the signal to be demodulated / decoded first may be determined based on the power ratio. In this case, for example, after the desired signal is demodulated / decoded, a replica of the desired signal is generated and subtracted from the received signal. Then, with respect to the subtracted signal, the interference signal is demodulated / decoded using the channel estimated value estimated in S703. Then, a replica of the interference signal is generated, subtracted from the received signal, and the desired signal is demodulated / decoded again based on the subtraction result. In this way, when the iterative processing is executed, it is not necessary for the interference signal to be demodulated / decoded first.

By setting a blank frame as described above and providing a period during which only the interference signal is received in the receiving device, it is possible to improve the accuracy of the channel estimation of the interference signal and the replica, and the interference signal from the received signal can be improved. It is possible to remove the influence of the above with high accuracy.

The present invention is not limited to the above embodiments, and various modifications and modifications can be made without departing from the spirit and scope of the present invention. Therefore, in order to make the scope of the present invention public, the following claims are attached.

Claims (15)

A receiving device that receives a signal transmitted from a transmitting device.
The receiving means for receiving the signal and
A setting means for setting a blank frame that does not include data in a frame during communication with the transmission device, and
An estimation means for estimating the signal channel of another system in the period corresponding to the blank frame, and
A removing means for removing interference components from the other system contained in the signal received by the receiving means based on the channel.
A demodulation means that demodulates the data transmitted from the transmission device based on the signal from which the interference component has been removed, and
A receiving device characterized by having. The receiving device according to claim 1, wherein the setting means sets the blank frame based on the radio quality of the signal transmitted from the transmitting device. The receiving device according to claim 2, wherein the radio quality is based on a reception success rate of a signal from the transmitting device. The setting means sets the blank frame having a length of two or more frames of a signal transmitted from the transmitting device and a frame of a signal from the other system, whichever is longer. The receiving device according to any one of claims 1 to 3, wherein the receiving device is characterized by the above. The receiving device according to any one of claims 1 to 4, wherein the setting means communicates a control signal for setting the blank frame with the transmitting device. A transmitter that transmits a signal to a receiver
Setting a blank frame that does not contain data in the frame being communicated with the receiver that the receiver uses to estimate the channel for signals from other systems that should be removed in the receiver. Setting means to be performed and
A transmission means that does not transmit a signal in the blank frame but transmits a signal to the receiving device in a frame other than the blank frame.
A transmitter characterized by having. The transmitting device according to claim 6, wherein the setting means sets the blank frame based on the radio quality of the signal transmitted by the transmitting means in the receiving device. The transmitting device according to claim 7, wherein the radio quality is based on a reception success rate of a signal from the transmitting means in the receiving device. The transmission according to claim 7, wherein the radio quality is based on the number of the receiving devices that have succeeded in receiving the signals transmitted to the plurality of receiving devices, respectively. Device. The setting means has a length of two or more frames of a signal transmitted by the transmitting means and a frame of a signal from another system to be removed by the receiving device, whichever is longer. The transmission device according to any one of claims 6 to 9, wherein the blank frame is set as a period. The transmitting device according to any one of claims 6 to 10, wherein the setting means communicates a control signal for setting the blank frame with the receiving device. A communication method performed by a receiving device that receives a signal transmitted from the transmitting device.
Setting a blank frame that does not include data in the frame during communication with the transmitter
Estimating the signal channels of other systems during the period corresponding to the blank frame,
To remove the interfering components from the other system contained in the received signal based on the channel.
Demodulating the data transmitted from the transmitter based on the signal from which the interference component has been removed, and
A communication method characterized by including. A communication method performed by a transmitting device that transmits a signal to a receiving device.
Setting a blank frame that does not contain data in the frame being communicated with the receiver that the receiver uses to estimate the channel for signals from other systems that should be removed in the receiver. To do and
Not transmitting a signal in the blank frame, but transmitting a signal to the receiving device in a frame other than the blank frame.
A communication method characterized by including. To the computer provided in the receiving device that receives the signal transmitted from the transmitting device,
In the frame during communication with the transmitting device, a blank frame that does not include data is set.
The signal channels of other systems are estimated during the period corresponding to the blank frame.
Based on the channel, the interfering component from the other system contained in the received signal is removed.
Based on the signal from which the interference component has been removed, the data transmitted from the transmitter is demodulated.
Program for. To a computer equipped with a transmitter that sends a signal to the receiver
Setting a blank frame that does not contain data in the frame being communicated with the receiver that the receiver uses to estimate the channel for signals from other systems that should be removed in the receiver. Let me do
The signal is not transmitted in the blank frame, and the signal is transmitted to the receiving device in the frame other than the blank frame.
Program for.

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