WO2005027376A1

WO2005027376A1 - Array antenna beam formation method and array antenna radio communication device

Info

Publication number: WO2005027376A1
Application number: PCT/JP2003/011528
Authority: WO
Inventors: Masafumi Tsutsui
Original assignee: Fujitsu Limited
Priority date: 2003-09-09
Filing date: 2003-09-09
Publication date: 2005-03-24

Abstract

An array antenna beam formation method for a radio communication system performing multi-connection. The method includes steps of: receiving a signal transmitted from a sector by a plurality of reception circuit sections respectively connected to a plurality of antennas constituting the array antenna; receiving the reception signal from the plurality of reception circuit sections by a plurality of receivers to form a beam and simultaneously demodulating and decoding the multi-connected channels; identifying receivers in use and assigning a new channel to be received to the receiver not in use; and controlling which beam of the plurality of pattern beams dividing the one sector according to the channel assignment is to be formed by the plurality of receivers. It is possible to obtain a gain of the array antenna even for a signal whose coming direction cannot be predicted and receive the signal. Thus, it is possible to effectively use the receivers in the device flexibly according to the communication environment and suppress increase of the number of receivers.

Description

TECHNICAL FIELD The present invention relates to an array antenna beam forming method and an array antenna wireless communication apparatus.

The present invention relates to an array antenna beam forming method and an array antenna wireless communication device, and more particularly to an array antenna beam forming method and an array antenna wireless communication device of a wireless communication system that performs multiple access. Background art

In a wireless communication system that performs multiple access such as a mobile phone, by performing beamforming using an array antenna, it is possible to improve signal quality, suppress interference signals, reduce transmission power, and the like.

FIG. 1 shows a block diagram of a conventional array antenna wireless communication device. This array antenna wireless communication apparatus is applied to a base station of a mobile communication system such as CDMA (Code Division Multi-Tip 1e Access).

In the figure, a signal received by an array antenna 11 composed of a plurality of antenna elements 10 i to 10 Om is amplified by a radio reception circuit unit 12 i to 12 m provided for each antenna, frequency conversion, After being band-limited and converted to a baseband signal, it is converted to a digital signal by AZD converters 13 t to 13 m. The baseband signal processing unit 14 is a multi-channel (n-channel in the figure) receivers 1 to! Provided for simultaneously processing multiple access. It consists of 5n.

In order to efficiently allocate the plurality of receivers 1Sil 5n to the user who performs communication, the channel allocation control unit 16 grasps the usage status of the receivers 15i to 15n and allocates the receivers. The output signal of the channel to which the receiver is assigned is sent to the wireless network control device via the wired transmission line interface unit 17.

The receivers 15 to 15 n provided in the baseband signal processing unit 14 perform beam forming using array antennas 12 to 12 m for each channel. Do. The weight used for beamforming is estimated based on the algorithm in the receiver of each channel.

Specific algorithms include beam steering based on the estimation of the arrival direction of the desired wave, null steering that directs the null point in the direction of the interference wave based on the MMSE (minimum mean square error) criterion, and beam steering and null. A method combining steering is used.

In addition, the receivers 15 to 15 n are the same as ordinary receivers that do not use an array antenna, such as a synchronization circuit, a demodulation circuit corresponding to the modulation method, and a decoding circuit that returns a signal that has been converted into a radio frame to the original data. Etc.

In this conventional technique, a bit estimation for beamforming is performed in a receiver of each channel. Therefore, in communications where received signals such as voice are continuously input to the receiver, the accuracy of the formed beam can be gradually improved, and the time required for the formed beam to stabilize can be reduced. Except for stable beam forming.

According to Patent Document 1, the traffic monitoring unit monitors the radio channel usage rate of each sector from the transmission / reception unit, and switches the directivity to the directivity switching unit based on a change in the radio channel usage rate of each sector. A zone control method is described in which the sector and the number of radio channels allocated to the transmission / reception section are changed, and when the radio channel usage rate is low, the sector is made smaller to narrow the directivity of radio waves and reduce the influence of interference waves. .

Further, in Patent Document 2, an antenna that generates a plurality of beams, a control unit controls a pattern of each beam based on communication amount information communicated by each beam, and sets an excitation weight for each beam by a weight setting unit. An adaptive antenna that adaptively controls the beam width and beam direction of each sector beam so as to equalize the communication volume accommodated in each sector is described.

Further, in Patent Document 3, a signal from a wireless terminal is received by an antenna array, and either an omni beam or a narrow beam is selected based on the other party information based on the received signal, and a multi-beam forming unit forms an antenna pattern. A wireless communication method for reducing co-frequency interference power is described.

Patent Document 1 Unexamined Japanese Patent Publication No. Hei 5—336072

Patent Document 2

Japanese Patent Application Laid-Open No. H10-10-26139

Patent Document 3

Japanese Patent Application Laid-Open No. 9-284024

In the prior art shown in FIG. 1, beamforming is performed by performing weight estimation for array antenna signal processing for each channel in each receiver. Therefore, when a signal is continuously transmitted like voice, the channel is continuously allocated until the call ends.

As a result, by gradually improving the accuracy of the formed beam, a stable beam can be formed and the gain of the array antenna can be obtained except for a short time at the beginning of communication until the formed beam converges. .

However, in wireless packet communication, which is expected to increase in the future, since the system is designed on the assumption that signal transmission is completed for each packet, it is necessary to design wireless communication devices so that processing can be performed in bucket units . Also, in a system using random access as an access method, it is necessary to design a device that can immediately process a signal transmitted from an unspecified user whose arrival direction cannot be predicted.

For this reason, unlike the conventional array antenna radio communication device mainly dealing with voice communication, a method of immediately forming a beam for an incoming signal is required. Conversely, if low-precision beam forming is performed using the conventional beam forming method, the gain of the array antenna cannot be sufficiently obtained. There was a problem. Disclosure of the invention

The present invention is capable of receiving signals with unpredictable directions of arrival by obtaining the gain of an array antenna, suppressing the increase in the number of receivers by flexibly and effectively utilizing the receivers in the apparatus according to the communication environment. It is a general object to provide an array antenna wireless communication device capable of performing the above. In order to achieve this object, the present invention relates to an array antenna beam forming method for a multiple access wireless communication system, which is connected to each of a plurality of antennas constituting an array antenna and transmitted from one sector. The received signals are received by a plurality of receiving circuit units, and the received signals are supplied from the plurality of receiving circuit units to a plurality of receivers to form a beam, and the multiple connected channels are simultaneously demodulated and decoded, and used. The receiver in the middle is grasped, and a new receiving channel is allocated to an unused receiver, and according to the channel allocation, any one of the beams of the plurality of patterns that divide the one sector is used as the plurality of beams. The configuration is such that allocation control is performed to determine whether the signal is formed by the receiver.

According to such an array antenna radio communication device, it is possible to obtain and receive an array antenna gain even for a signal whose direction of arrival cannot be predicted, and flexibly use the receiver in the device flexibly according to the communication environment Thus, an increase in the number of receivers can be suppressed. Brief Description of Drawings

FIG. 1 is a block diagram of a conventional array antenna wireless communication device.

FIG. 2 is a block diagram of the array antenna radio communication device according to the first embodiment of the present invention.

FIG. 3 is a block diagram of a receiver according to a first embodiment of the present invention. FIG. 4 is a block diagram of an embodiment of the beamformer.

FIG. 5 is a diagram showing an image in which four beams are formed in a sector.

FIG. 6 is a diagram showing one embodiment of a beam pattern for forming four beams in a sector.

FIG. 7 is a diagram illustrating an embodiment of a channel management table provided in the channel assignment control unit.

FIG. 8 is a flowchart of a channel assignment process executed by the channel assignment control unit.

FIG. 9 is a diagram illustrating an example of the user distribution of the beams A, B, C, and D and the time variation of the number of assigned receivers.

FIG. 10 is a block diagram of a second embodiment of the array antenna wireless communication apparatus of the present invention. FIG. 11 is a block diagram of a second embodiment of the receiver used in the present invention. FIG. 12 is a time chart of received signal processing in an arbitrary receiver. FIG. 13 is a block diagram of a third embodiment of the receiver used in the present invention. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 2 shows a block diagram of a first embodiment of the array antenna wireless communication apparatus of the present invention. This array antenna wireless communication device is applied to a base station of a mobile communication system such as CDMA. In the figure, the signals received by a plurality of antenna elements 2 (^ 2 to 2 Om) are received by radio receiving circuit units 22 to 22 m provided for each antenna. After being amplified, frequency-converted, band-limited and converted to a baseband signal, it is converted to a digital signal with AZD conversion ^^ 23i to 23m. It consists of multiple channels of receivers 25 丄 to 5n provided for simultaneous processing.

In order to efficiently allocate a plurality of receivers 25i to 25n to users who communicate, the channel assignment control unit 26 grasps the usage status of the receivers 25 to 25n and allocates receivers. Do. The output signal of the channel to which the receiver is assigned is sent to the wireless network control device via the wired transmission line interface unit 28.

The channel assignment control unit 26 assigns a new receiving channel to unused receivers, grasps which receiver is in use \ output data from the receiver being used, and ends communication. When this happens, the current status of the receiver, such as a receiver that can be assigned, is monitored. The wired transmission path interface unit 28 determines from which receiver data is output based on the information from the channel assignment control unit 26.

In addition, a beam control unit 27 that integrally controls the beam is provided for each of the receivers 25 to 25 n provided in the baseband signal processing unit 24. The beam control unit 27 operates in cooperation with the channel assignment control unit 26. The beam controller 27 has a plurality of gates for forming beams in different directions for each of the receivers 25i to 25n, and each of the receivers 25i to 25n has Using one of the beams Do the faith.

That is, the channel assignment of the receiver 25 25 n is performed only for signals from the set beam direction. However, if the weight of the receiver is fixed, only signals in a specific direction can be received, and the receiver assignment is limited to that direction. As a result, it is necessary to prepare more receivers. Come. Therefore, in the present invention, the frequently used beams (directions) are monitored together with the channel allocation frequency, the number of receivers that set the less frequently used beams is reduced, and the more frequently used beams are formed. By doing so, rather than assigning beams to be formed equally to all receivers, assignments are made according to the usage status.

FIG. 3 shows a receiver used in the present invention. ~? ! FIG. 1 shows a block diagram of a first embodiment of FIG. Here, it is assumed that the base station of the mobile communication system to which the array antenna wireless communication device is applied uses a sector antenna configuration, and an array antenna is used in each sector. The number of array antennas in each sector is, for example, four, and four beams can be set in one sector. Alternatively, a beam number may be designated by the beam control unit 27, and the beam may be formed using a weight table provided in each receiver.

3, beam former 3 1 performs beamforming by performing the synthesis after multiplied by the different complex weights to the digital • baseband signals from the antenna 2 0 2 0 _4. FIG. 4 shows a block diagram of an embodiment of the beam former 31. Antenna 2 () digital 'baseband signals from 2 0 ₄ is supplied to the multiplier 3 2 i 3 2 ₄ are multiplied by a complex way Wi W, thereafter, the output signal of the multiplier 3 2 3 2 ₄ adds The signals are added and synthesized by the device 3 3.

In the beam controller 27, four complex weights for forming the four beams are prepared as a table, and one of the weights is selected and set for each of the multipliers 3 2 i 3 2 _4. Four beams can be formed.

In FIG. 3, the received signal output from the beam former 31 is supplied to a demodulation circuit 35 and a synchronization circuit 36. The synchronization circuit 36 detects a predetermined synchronization pattern from the received signal and supplies a synchronization detection signal to the demodulation circuit 35. The demodulation circuit 35 demodulates the received signal in synchronization with the synchronization detection signal and supplies the demodulated signal to the decoding circuit 37. The decoding circuit 37 is a demodulated signal Is decrypted and the original data is output. The status register 38 holds the channel use state (used / unused) of the own receiver, and this use state is notified to the channel assignment control unit 26.

Figure 5 shows an image in which four beams A, B, C, and D are formed in a sector ST with an opening angle of 120 degrees. In addition, FIG. 6 shows that four elements formed at an antenna interval of 0.57 λ (λ: wavelength of carrier frequency) using a four-element equally-spaced linear array antenna in a sector ST having a spread of 120 degrees. A specific example of a beam will be described.

A mobile station existing in a sector transmits a signal to access a base station, and the base station receives a signal of the sector. For reception at the base station, it is necessary to perform a series of reception processing such as synchronization acquisition and demodulation processing even if the time and direction of the transmitted signal are unknown, such as random access.

Furthermore, devices using an array antenna are superior in terms of the ability to perform beamforming in the direction in which a signal arrives and perform reception, in terms of the transmission power of mobile stations, and the reduction of interference with other users performing multiple access. This is one reason for using array antennas.

However, since signals such as random access and packet communication generally end in a short time, the method of estimating the direction of arrival from the signals received by each antenna and performing beamforming based on the estimation result is not sufficient for estimating the direction. Beamforming is performed without obtaining sufficient time, and as a result, the effect of + minute beamforming cannot be obtained.

Therefore, in the present invention, by performing multi-beam reception using a fixed beam in order to suppress deterioration of characteristics at the time of initial beam formation, reception from a beam from each beam direction is obtained with the effect of an array antenna. If the drop in gain between adjacent beams poses a problem, prepare a number of beams that have a peak in that direction. However, since the sector is divided by multiple beams, the number of necessary receivers is required to be the number of beams to be formed.

The plurality of receivers 25 i to 25 η provided in the baseband signal processing unit 24 have a configuration capable of forming a plurality of beams that divide a sector, and the channel allocation control unit 26 And all (or most) In this case, the receiver can be configured to form any beam, so that it is possible to form a beam in the direction of the user who performs communication.

In particular, in communication in which random access is performed, it is possible to receive only a signal transmitted from a beam direction set in advance with gain by beamforming.

Here, the number of channels is assumed to be 100 per sector, the number of antennas is assumed to be a 4-element array, and the number of formed beams is assumed to be 4 (fixed beam).

FIG. 7 shows an embodiment of the channel management table 29 provided in the channel assignment control unit 26. Channel management table 29 is a receiver? What? ! ! For channels 1 to 100 corresponding to (n = 100), the usage status of the channel (1 is in use, 0 is unused or usable), and the allocated beam (A, B, C, D) of the channel Is stored.

FIG. 8 shows a flowchart of the channel assignment process executed by the channel assignment control unit 26. In the initial setting of step S10, 25 channels are assigned to each beam A, B, C, D. Thus, for example, beam A is assigned to channels 1 to 25, beam B is assigned to channels 26 to 50, beam C is assigned to channels 51 to 5, and beam D is assigned to channels 76 to 100. .

Next, in step S12, it is determined whether the force has passed for a certain time or not. If the certain time has not passed, each of the receivers. . The channel use state is fetched from the state register, and time averaging is performed, and the channel management table 29 is updated. On the other hand, if the predetermined time has elapsed in step S12, the process proceeds to step S16.

Thereafter, in step S16, the channels of the beams A, B, C, and D are reassigned. Here, the number of used channels na, nb, nc.nd of each beam is counted from the channel management table 29, and the number of allocated channels Na, Nb, Nc, N of each beam A, B, C, D is calculated from the following equation. Determine d.

Na = 1 00 Xn a / (n a + nb + n c + n d)

Nb = 100 Xn b / (na + nb + nc + nd) Nc = 100Xn c / (na + nb + n c + nd)

Nd = 100Xnd / (na + nb + nc + nd)

The above formula represents the case where 100 channels are allocated in proportion to the usage based on the observation results of channel usage, and corrections are made to prevent the number of allocated channels from actually becoming 0 is necessary.

Thereafter, in step S18, the allocated beam of the unused channel in the channel management table 29 is rewritten so that the number of allocated channels becomes Na, Nb, Nc, and Nd, and the process proceeds to step S12. Although FIG. 7 shows an example in which the beams A, B, C, and D are assigned so that the channel numbers are consecutive, the channel numbers assigned to the beams need not necessarily be consecutive. Further, the present invention is not limited to the above equation, and various algorithms suitable for the system can be applied.

Figure 9 shows an example of the user distribution of each beam A, B, C, and D and the time variation of the number of assigned receivers. In the figure, the number of communication users of beams A, B, C, and D at each time is shown by a bar graph. Further, the number of receivers of the beam A according to the present invention is indicated by a circle line graph, the number of receivers of the beam B is indicated by a triangle line graph, the number of receivers of the beam C is indicated by a square line graph, and the number of receivers of the beam D is indicated by a square line graph. The number of receivers is indicated by a line graph marked with X. At time to, power is turned on and operation (service) is started, and each beam has the following features.

Beam A: The number of communication users reaches the maximum at time t4, at which time it exceeds 25 channels.

Beam B: The number of communication users is small overall and does not exceed 25 channels. Beam C: The number of communication users reaches 53 channels, the maximum for all beams at time t7, and 25 during the time t5 to t9. Channel is exceeded.

Beam D: The number of communication users reaches a maximum at time t4, and exceeds 25 channels at this time.

In the example of Fig. 9, if receivers for 100 channels are equally allocated to four beams, all beams A to D have 25 channels, so there is no problem with beam B, which has few communication users, but beam A , C and D, the number of communication users is the receiver channel It can be seen that the number exceeds the number and all communications cannot be accommodated. In particular, when the number of communication users is large and at time t7 of beam C, only less than half of the communication can be accommodated.

In the present invention, since the number of communication users in the initial state is unknown, 100 channel receivers are equally allocated to four beams, and there are 25 channels all the way. By allocating the receivers, the number of receivers forming each beam changes as shown by the polygonal line in Fig. 9, and the number of users that cannot be accommodated can be reduced.

In FIG. 9, when the number of all communication users in the sector at time t7 when the number of communication users is maximized is 100% including a margin and 100% of channels are allocated, 100%

X I. 2 = 1 2 0 (channel). That is, in the present invention, if the number of receivers per sector is 120 channels, all communications shown in FIG. 9 can be accommodated.

On the other hand, in the prior art, if a 10% channel is allocated as a margin to the number of communication users 53 of beam C at time t7 when the number of communication users for each beam is maximum, then 5 3 X 1.1 = 6 3 (channels). Further multiplying the number of beams by 4 gives 6 3 X 4 = 2

5 2 (channels). That is, by applying the present invention, the number of prepared receivers can be reduced to half or less as compared with the conventional case.

In this way, a large number of receivers are allocated to frequently used beams by monitoring the allocation status of receivers and the allocation status of their beams. In other words, by performing efficient beam allocation and receiver allocation according to the direction of arrival of the channel to be accessed and the environment in which it is used, an array antenna receiver that efficiently uses the receiver without deteriorating its characteristics Communication device.

FIG. 10 shows a block diagram of a second embodiment of the array antenna wireless communication apparatus of the present invention. In the figure, the same parts as those in FIG. 2 are denoted by the same reference numerals. In FIG. 10, a signal received by an array antenna 21 composed of a plurality of antenna elements 2 (^ to? O m is provided for each antenna through a duplexer (DUP) 5 (^ to The signal is supplied to the radio receiving circuit section 22i to 22m, where it is amplified, frequency-converted, band-limited and converted to a baseband signal, and then converted to a digital signal with an AZD variable ^ 23 to 23m. The baseband signal processor 24 performs simultaneous multiple access. It is configured with receivers 25i to 25n for a plurality of channels provided for processing.

In order to efficiently allocate a plurality of receivers 25i to 25n to users who communicate, the channel allocation control unit 26 grasps the usage status of the receivers 25i to 25n and allocates receivers. I do. The output signal of the channel to which the receiver is assigned is sent to the wireless network control device via the wired transmission line interface unit 28.

The channel allocation control unit 26 allocates a new receiving channel to an unused receiver, grasps which receiver is in use, and determines whether there is output data from the receiver in use, and terminates communication. When this happens, the current status of the receiver, such as a receiver that can be assigned, is monitored. The wired transmission path interface unit 28 determines from which receiver data is output based on the information from the channel assignment control unit 26.

In addition, a beam control unit 27 that integrally controls the beam is provided for each of the receivers 25 to 25 n provided in the baseband signal processing unit 24. The beam control unit 27 can operate in cooperation with the channel assignment control unit 26. The beam control unit 27 has a plurality of weights for forming beams in different directions for each of the receivers 25 i to 25 n, and each of the receivers 25 ₁ to 25 n has _one of the weights. Reception is performed using the beam.

The channel assignment control unit 26 monitors frequently used beams (directions) together with the channel assignment frequency, reduces the number of receivers that set infrequently used beams, and forms many frequently used beams. By doing so, allocation is made according to the usage status.

On the other hand, the data of each channel sent from the wireless network controller is transmitted to the transmitters 54 i to 54 of the multiple channels constituting the baseband signal processor 53 via the wired transmission path interface 52. n, each of which is coded for each channel, further modulated, and then forms a beam with a beamformer.

ビーム f The beamformer distributes the modulated signal to m multipliers and supplies them, and multiplies the m complex weights. The complex weights are supplied from the beam controller 27, and the complex weights for the beamformers of the receivers 25i to 25n and the transmission The complex weights for the beamformers of the machines 54i to 54n are the same. That is, the beam of each channel is the same for transmission and reception.

Transmitters 54 to 54n output data of m systems output by n are multiplexed by the synthesizing units 55 to 55m, converted to analog signals by the DZA transformers 56 _{1 to} 56m, and transmitted by radio. After being amplified, frequency-converted, and band-limited by the circuit unit 5 iS 7 m, the signal is transmitted from the antenna elements 20 i to 2 Om through the duplexer (DUP) 50 to 5 Om.

In the above-described first and second embodiments, the received signal processing is performed using the fixed beam set by the beam control unit 27. Therefore, when communication is performed continuously while moving, the moving beam deviates from the beam. If the beam is stationary between adjacent beams, the gain will slightly decrease. Therefore, an embodiment for avoiding such a state will be described.

Figure 11 shows the receiver used in the present invention. 2 to 25 η show block diagrams of the second embodiment. In the figure, the same parts as those in FIG. 3 are denoted by the same reference numerals. In Figure 1 1, bi Mufoma 3 1 intends row beamforming by performing synthesis after multiplied by the different complex weights to the digital 'baseband signals from the antenna 2 0 i~ 2 0 _4. In addition to this configuration, a weight estimating unit 40 for forming an adaptive beam in each channel is provided.

The received signal output from the beamformer 31 is supplied to a demodulation circuit 35 and a synchronization circuit 36. The synchronization circuit 36 detects a predetermined synchronization pattern from the received signal and supplies a synchronization detection signal to the demodulation circuit 35. The demodulation circuit 35 demodulates the received signal in synchronization with the synchronization detection signal, and supplies the demodulated signal to the decoding circuit 37. The decoding circuit 37 decodes the demodulated signal and outputs the original data. The status register 38 holds the channel usage status (used / unused) of the own receiver, and this usage status is notified to the channel assignment control unit 26.

FIG. 12 shows a time chart of the received signal processing in an arbitrary receiver. In the figure, when communication is completed at the receiver, the status register 38 of the receiver is set to unused (= 0).

The channel assignment control unit 26 recognizes that the receiver is unused, and Update the file management table 29. As described in the first embodiment, the beam control unit 27 sets a new initial beam for an unused receiver according to the use state of each beam. Upon receiving a new beam setting, the receiver enters the status register 38 in use (= 1), and enters a standby state for receiving a random access signal.

When a random access signal arrives from the direction of the beam being formed, the received signal processing is started using the set fixed beam. At the same time, the weight estimating unit 40 provided in each receiver performs weight estimation processing by, for example, feedback control or feedforward control in order to adaptively form a beam according to the situation of the user performing communication. Start. Generally, such an adaptive weight estimation process requires a certain amount of time for highly accurate weight estimation.

If the communication time of all possible communication is less than the time required for this convergence, it is meaningless to provide a weight estimator, and the configuration of the first embodiment using only the fixed beam is sufficient. It is. However, in a system that can communicate continuously for a long time, it is necessary to follow the movement of the communication user between beams, and the gain due to the existence of communication between adjacent beams for a long time is necessary. It is desirable to cope with the decrease in

Therefore, in the present embodiment, reception is performed using the fixed beam set by the beam control unit 27 until the weight estimation accuracy is obtained, and communication is performed even after the weight estimation accuracy is obtained by the weight estimation unit 40. If continuation is performed, tracking is performed for the communication user by switching to the adaptive beam estimated by the weight estimation unit 40 of each receiver. As a result, stable beamforming and communication can be performed. When the communication is completed, the status register is set to unused (= 0), so that a new beam assignment is to be waited.

FIG. 13 shows a block diagram of a third embodiment of receivers 25 to 25 n used in the present invention. In the figure, the same parts as those in FIG. 3 are denoted by the same reference numerals. 1 3, bi Mufoma 6 0, antenna 2 0 to 2 0 m in the digital baseband signal from ₄ to carry out the synthesis then multiplied by the different complex weight (Fig. 1 3, m = 4) Type The beamforming (fixed beam) is performed, and the received signals of m types of beams are supplied to the selectors 61 of the receivers 25 to 25n. In other words, beamform Each block 60 has the configuration shown in FIG.

The beam control unit 62 supplies selection information for instructing selection of one beam from m types of beams to the selectors 61 of the receivers 25 to 25 n. The selector 61 selects a reception signal of one type of beam according to the selection information.

The received signal output from the selector 61 is supplied to the demodulation circuit 35 and the synchronization circuit 36. The synchronization circuit 36 detects a predetermined synchronization pattern from the received signal and supplies a synchronization detection signal to the demodulation circuit 35. The demodulation circuit 35 demodulates the received signal in synchronization with the synchronization detection signal and supplies the demodulated signal to the decoding circuit 37. The decoding circuit 37 decodes the demodulated signal, returns it to the original data, and outputs it. The status register 38 holds the channel usage status (used / unused) of the own receiver, and this usage status is notified to the channel assignment control unit 26. Thus, the beamformer 60 is received. By sharing the devices 25i to 25n, the circuit scale of the receivers 25 to 25n can be reduced.

As described above, according to the present invention, since the received signal is processed in the direction using the fixed beam, the signal of the array antenna can be received and obtained even for a signal whose arrival direction cannot be predicted, such as a random access signal. can do. In addition, since a large number of receivers for multiple access and the beams formed by them are managed in a unified manner, and the beams are allocated to the receivers according to the beam usage conditions, the increase in the number of receivers due to the use of array antennas has been reduced. In addition, more communication users can be accommodated.

In a system that performs continuous communication, switching is performed after adaptive beam convergence by a weight estimator provided in each receiver, so that stable communication can be performed continuously.

This means that a wireless communication device that uses an array antenna can perform packet communication and random access smoothly, can increase the communication capacity while suppressing the number of channels of the device, and maintain a stable Beam capture can be performed. Therefore, it is possible to stably operate the array antenna wireless communication device whose communication quality depends on the accuracy of the formed beam.

Note that the wireless receiving circuit units 21 to 2 lm correspond to the receiving circuit unit described in the claims. The channel assignment control unit 26 corresponds to the channel assignment control unit, the beamformers 31 and 60 correspond to the beam forming unit, the beam control unit 27 corresponds to the beam control unit, and the weight estimation unit 40 corresponds to the weight. The selector 61 corresponds to the selecting means, corresponding to the estimating means.

Claims

The scope of the claims

1. Beam forming method of array antenna of wireless communication system with multiple access 5)

A signal transmitted from one sector connected to each of a plurality of antennas constituting an array antenna is received by a plurality of receiving circuit units,

A plurality of receivers are supplied with reception signals from the plurality of reception circuit units to form a beam, and simultaneously demodulate and decode the multiple-connected channels;

Recognizing a receiver in use and allocating a new reception channel to an unused receiver, and allocating any one of the plurality of pattern beams for dividing the one sector according to the channel allocation to the plurality of beams. A beam forming method for an antenna that assigns and controls whether to form it at the receiver.

2. The beam forming method for an array antenna according to claim 1,

Each receiver performs weight estimation to form an adaptive beam in each channel,

A beam forming method for an array antenna in which each receiver performs beam forming by control according to the channel assignment, and then performs beam forming with the weight estimated by the weight estimation.

3. A beam forming method for an array antenna of a wireless communication system performing multiple access,

The signals transmitted from one sector connected to each of a plurality of antennas constituting the array antenna are received by a plurality of receiving circuit units,

A plurality of receiving circuits supplied from the plurality of receiving circuit units to divide the one sector; Turn beam formation,

A plurality of receivers select one beam of the plurality of patterns of beams, and simultaneously demodulate and decode the multiplexed channels; Recognizing a receiver in use and allocating a channel to be received to an unused receiver, and arranging which of the plurality of patterns of beams that divide the one sector according to the channel allocation into the plurality of receptions A beamforming method for a single antenna that assigns and controls whether or not to select a device.

4. An array antenna wireless communication device of a wireless communication system for performing multiple access,

A plurality of receiving circuit units connected to each of the plurality of antennas constituting the array antenna and receiving signals transmitted from one sector;

A plurality of receivers, comprising: a beam forming unit configured to perform beam forming by receiving a reception signal from the plurality of reception circuit units, and simultaneously demodulating and decoding channels connected in multiple access;

Channel allocation control means for recognizing a receiver in use and allocating a channel to be received to an unused receiver;

An array antenna having beam control means for allocating and controlling which of a plurality of patterns of beams for dividing the one sector in accordance with the channel assignment is to be formed by the beam forming means of the plurality of receivers; Wireless communication device.

5. The array antenna wireless communication device according to claim 4,

An array antenna wireless communication apparatus, wherein the beam control means allocates more beams to the beam forming means of the plurality of receivers in accordance with the frequency of use of the beam allocated to the receiver in use.

6. The array antenna wireless communication device according to claim 5,

The array antenna radio communication apparatus, wherein the beam control means uniformly allocates the plurality of patterns of beams to the beam forming means of the plurality of receivers in an initial state.

7. The array antenna wireless communication device according to any one of claims 4 to 6, Each receiver has weight estimation means for forming an adaptive beam in each channel,

An array antenna radio communication apparatus for controlling the beam forming unit of each receiver by the beam control unit to form a beam, and then forming the beam by the beam forming unit using the weight estimated by the weight estimating unit.

8. The array antenna wireless communication device according to any one of claims 4 to 7,

A beam forming means for beam forming a transmission signal, a plurality of transmitters for simultaneously coding and modulating the multiple-accessed channels,

A wireless antenna radio communication device for controlling beam forming means of the plurality of transmitters together with beam forming means of the plurality of receivers by the beam control means.

9. An array antenna wireless communication device of a wireless communication system for performing multiple access,

A plurality of receiving circuit units connected to a plurality of antennas constituting the array antenna and receiving signals transmitted from one sector,

Beam forming means for receiving a received signal from the plurality of receiving circuit units and dividing the one sector to perform beam forming of a plurality of patterns;

A plurality of receivers for selecting one beam out of a plurality of patterns of beams supplied from the beam forming unit, and for simultaneously demodulating and decoding multiple-accessed channels;

Array antenna wireless communication having beam control means for allocating and controlling which beam of the plurality of patterns for dividing the one sector in accordance with the channel allocation is selected by the plurality of receiver selecting means. apparatus.