JP2002300105A - Wireless communication system, weight vector controller and weight vector generating method, and terminal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wireless communication system that can reduce the failure rate of channel setup even when terminals requesting channel setup are concentrated on the same area. SOLUTION: A terminal to which an information channel is assigned informs a base station about the presence of an adjacent terminal predicting a channel setup request by the information slot. A weight controller 27 of an adaptive array of the base station generates a weight vector in the succeeding control slot based on the distribution of directions of request terminals collected in one frame in a way that the width of the generated beam is narrowed in a direction in which the distribution of the request terminals is much and the width of the generated beam is widened in a direction in which the distribution of the request terminals is less.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a radio communication system capable of simultaneously communicating with a plurality of terminals by space division multiplexing, a weight vector control device and a weight vector generation method for the radio communication system, and a terminal device. .

[0002]

2. Description of the Related Art In a wireless communication system, there is space division multiplexing (SDMA) as a means for increasing subscriber capacity. As shown in FIG. 20, a plurality of terminals 1003 are formed by forming a beam having a directional gain in each terminal direction by an adaptive array 1002 provided in a base station 1001.
To enable simultaneous communication.

FIG. 21 shows a configuration example of an adaptive array 1002 when the number of multiplexing is three. Beam forming circuit 10
21, 1022, 1023, the weighting device 121
1-11214, 1221-1224, 1231-123
4 and an appropriate weight vector.
Each of the antenna elements 1011 at 210, 1220 and 1230
By weighting and combining the outputs of # 10 to # 1014, a beam having the maximum directivity in the direction of the target terminal can be formed. The same applies when the multiplexing number is 4 or more,
A beam is formed so as to direct the maximum directivity toward the target terminal.

[0004]

In the conventional system, at the time when a terminal makes a channel establishment request in a control slot, the direction of the terminal is unknown to the base station.
Therefore, as shown in FIG. 22, in the control slot, a beam is formed by equally dividing the coverage area covered by the base station according to the direction. By doing so, a channel establishment request signal can be received regardless of the position of the terminal. However, in FIG. 22, the terminals 1311 and 1312 in the same beam 1302 fail to establish a channel due to collision of channel establishment requests. As described above, there is a problem that the probability of the channel establishment request failing increases when the terminal requesting the channel establishment is concentrated in a certain area.

The present invention has been made in consideration of the above circumstances, and presumes the direction of a terminal requesting a channel establishment, and determines, in a control slot, a direction in which it is estimated that many terminals request a channel establishment. A wireless communication system, a weight vector control apparatus, and a weight vector control method that form a beam with a narrow beam width to prevent a plurality of terminals from entering the same beam and reduce the probability of channel establishment failure. It is an object to provide a vector generation method and a terminal device.

[0006]

SUMMARY OF THE INVENTION The present invention is a radio communication system capable of simultaneously communicating with a plurality of terminals by space division multiplexing, comprising: a plurality of antenna elements; and a reception signal received by the plurality of antenna elements. A weighted combination outputs a received signal corresponding to a beam having a predetermined directivity pattern, a plurality of beam forming units, and a weight vector for controlling the weighting combination for each of the plurality of beam forming units. Control means for setting, wherein the control means collects information indicating a direction of a second terminal for notifying the own system of the presence of a first terminal for notifying a request for channel establishment in an information slot; Based on the distribution of directions of the second terminal collected during one frame by this means, the plurality of ways in the next control slot. · Characterized in that it comprises a generating means for generating a vector. According to the present invention, by notifying the wireless communication system in advance that a channel establishment request is to be made through a terminal that is communicating with the wireless communication system, the wireless communication system estimates in advance the direction of the terminal that makes the channel establishment request, By forming beams according to the distribution of terminals,
In the control slot, it is possible to prevent a plurality of terminals from entering the same beam and to reduce the rate of channel establishment failure.

[0007] Preferably, the generation means is configured such that, with respect to the beam widths of a plurality of beams used in the control slot, the beam width of the formed beam becomes narrower as the distribution of the second terminals increases. As the beam width of the formed beam becomes wider in the direction where the distribution of the terminals is smaller,
A plurality of the weight vectors in the control slot may be generated. By forming a beam with a narrow beam width in the direction in which it is estimated that there are many terminals requesting control channel establishment, it is possible to prevent multiple terminals from entering the same beam in a control slot, and the rate of channel establishment failure Can be reduced.

Preferably, the estimating means estimates the direction of the signal arriving at the control slot based on the signals received by the plurality of antenna elements, and, among the directions estimated by the means, establishes a channel. Means for estimating a direction in a beam formed by the weight vector set in the beam forming means for outputting a signal from a successful terminal as a direction of the terminal for which the channel establishment is successful. Of the signal arrival direction estimation results, the direction in the beam formed by the weight set in the beam forming circuit that outputs the signal from the terminal that has successfully established the channel is defined as the direction of the terminal that has successfully established the channel. In the control slot, it is possible to estimate the direction of the terminal that has made a channel establishment request and succeeded.

Preferably, when the second terminal receives the channel establishment request notice signal from the neighboring terminal, the second terminal is assigned to its own terminal only when the strength of the received signal is equal to or higher than a predetermined value. The signal for the notification may be transmitted to the wireless communication system using an existing information slot. By ignoring the channel establishment request notice signal whose received power is less than the predetermined value, it is possible to prevent a channel establishment request detection signal corresponding to the channel establishment request notice signal from a terminal at a long distance from being transmitted to the wireless communication system. it can. As a result, the distribution in the direction in which the establishment request is detected becomes accurate.

[0010] Preferably, when the second terminal receives the channel establishment request advance signal from the neighboring terminal and also receives the identifier advance signal, the second terminal transmits the information slot allocated to its own terminal. Using the to transmit the signal for notification to the wireless communication system, together with transmitting a signal for notification of the identifier, the collection means, with reference to the received identifier, the same The notification of the presence of the first terminal with an identifier may be reflected only once in the distribution even if the notification is received repeatedly. If the identifier of the terminal making the channel establishment request has already been received in the same frame, the signal from the receiver at this time is prevented from being input to the distribution storage device. Thus, the duplication of the channel establishment request notice signal from the same terminal can be prevented. As a result, the distribution in the direction in which the establishment request is detected becomes accurate.

Further, the present invention provides an adaptive signal processing apparatus having a plurality of beam forming means for outputting a reception signal corresponding to a beam having a predetermined directivity pattern by weighting and combining reception signals received by a plurality of antenna elements. A weight vector control device for an array, comprising: a setting means for setting a weight vector for controlling the weighting synthesis for each of the plurality of beam forming means; and First generating means for generating the weight vector to be set, and the weights to be set for each of the beam forming means in a control slot.
Second generating means for generating a vector.
Generating means for collecting information indicating the direction of the second terminal that notifies the own system of the presence of the first terminal that foretells a request for channel establishment in the information slot, and collects the information collected during one frame. And generating a plurality of the weight vectors in the next control slot based on the distribution of the terminal directions.

Further, the present invention is a terminal device capable of communicating with a wireless communication system capable of simultaneously communicating with a plurality of terminals by space division multiplexing, and a first device for performing communication with the wireless communication system. Transmission / reception means, second transmission / reception means for performing communication between neighboring terminals, and a channel establishment request notice signal when a channel establishment request is made in a control slot, and the generated channel establishment request notice Channel establishment notifying means for notifying a nearby terminal via the second transmitting / receiving means in a frame immediately before a frame for making a channel establishment request for a signal, and channel establishing request notice via the second transmitting / receiving means When a signal is detected, a channel establishment request detection signal is transmitted to the wireless communication system via the first transmission / reception means in an information slot allocated to the terminal itself. Characterized by comprising a channel establishment request detecting means for signal.

[0013] The present invention relating to the apparatus is also realized as an invention relating to a method, and the present invention relating to a method is also realized as an invention relating to an apparatus. The present invention is applicable to the invention relating to the weight control method, the invention relating to the terminal device, and the invention relating to the method (for example, the communication method) in the terminal device. Further, the present invention according to an apparatus or a method has a function of causing a computer to execute a procedure corresponding to the present invention (or causing a computer to function as means corresponding to the present invention, or a computer having a function corresponding to the present invention). The present invention is also realized as a program (for realizing), and is also realized as a computer-readable recording medium on which the program is recorded.

[0014]

Embodiments of the present invention will be described below with reference to the drawings.

(First Embodiment) FIG. 1 shows a first embodiment of the present invention.
1 shows an example of a communication system including a base station (wireless communication system) 1 to which the first embodiment is applied.

FIG. 2 shows a configuration example of the terminal 3 according to the present embodiment. As shown in FIG. 2, the terminal 3 includes a first transceiver 31, a first antenna 32, a second transceiver 33,
Second antenna 34, channel establishment request notice device 35,
A channel establishment request detecting device 36 is provided.

In the terminal 3, communication with the base station 1 is performed by a first transceiver 31. First transceiver 31
Is connected to a first antenna 32, through which signals are transmitted and received. On the other hand, communication between the terminals 3 is performed by the second transceiver 33. A second antenna 34 is connected to the second transceiver 33,
Signals are transmitted and received via the antenna 34.

When the terminal 3 makes a channel establishment request in the control slot, the channel establishment request announcement device 35 generates a channel establishment request announcement signal. This channel establishment request announcement signal is a frame immediately before a frame for which a channel establishment request is made, and is transmitted via the second transceiver 33 to
Notify neighboring terminals.

On the other hand, when the terminal 3 to which the information slot has already been assigned detects the channel establishment request notice signal from the neighboring other terminal 3 by the channel establishment request detecting device 36 via the second transceiver 33, , And transmits a channel establishment request detection signal to the base station 1 in the assigned information slot.

The specific configuration of the second transceiver 33 for performing transmission and reception between the terminals 3 includes, for example, Bluetooth (Bluetooth) which is a kind of local wireless network.
oth; for example, http: // www. blueto
oth. com) (which is described in detail in the document disclosed so as to be obtainable through the Internet). Of course, other transceivers can be used. Also,
For example, for a TDMA / TDD system transceiver,
In addition to communication with the base station, communication between terminals is also possible.
In this case, only one transceiver is required.

The base station 1 is provided with an adaptive array 2. By using the adaptive array 2 to avoid interference between terminals, simultaneous communication with a plurality of terminals 3 on the same channel is possible.

In this embodiment, a case will be described as an example where space division multiplexing (SDMA) of three terminals is performed using an adaptive array including four antenna elements.

FIG. 3 shows a configuration example of the adaptive array 2 provided in the base station 1 according to the present embodiment.

As shown in FIG. 3, the adaptive array has m (m is plural; FIG. 3 shows the case where m = 4) antenna elements 211 to 214 and m-system amplifiers (low-power amplifiers). Noise amplification) 221 to 224, m frequency converters 231 to 234, m system distributors 241 to 24
4 and n (n is plural: FIG. 3 shows a case where n = 3) systems of beam forming circuits 251 to 253, n systems of receivers 261 to 263, and a weight control device 27. .

The beam forming circuit 251 includes m weighters 2511 to 25114 and a combiner 2512. Similarly, beam forming circuit 252 includes m weighters 2521-25214 and combiner 2522. Similarly, the beam forming circuit 253 includes m weighters 253111 to 25314 and a combiner 2532.

Further, the weight control device 27 includes a control slot initial weight storage device 271, a weight setting device 272, a direction estimating device 273, and a correspondence storage device 2.
74, an information slot weight calculator 275, and a control slot weight calculator 276.

Now, in the adaptive array shown in FIG. 3, the received signals received by the antenna elements 211 to 214 are input to the corresponding amplifiers 221 to 224, respectively. Each of the amplifiers 221 to 224 amplifies the received signal.

The received signals amplified by the amplifiers 221 to 224 are respectively transmitted to the corresponding frequency converters 231 to 234.
Is input to Each of the frequency converters 231 to 234 converts the frequency band of the received signal from a radio frequency (RF) to an intermediate frequency (IF) or a baseband (BB).

The received signals frequency-converted by the frequency converters 231 to 234 respectively correspond to the corresponding distributors 241 to 241.
244. Each of the splitters 241 to 244 splits the received signal to form a beam forming circuit 251 to 253.
Is output to the weight control device 27.

As described above, the beam forming circuit 251 receives the signals from the distributors 241 to 244 from the respective antenna elements 211.
To 214 are input. The same applies to the beam forming circuits 252 and 253 and the weight control device 27.

The received signals input to the beam forming circuit 251 are respectively weighted by weighters 2511-251.
After being weighted at 14, they are combined at the combiner 2512 and transmitted to the receiver 261. Beam forming circuit 25
The same applies to 2,253.

Weighting devices 2511 to 25114, weighting devices 2521 to 25214, and weighting device 2
The weights of 5311 to 25314 are appropriately set by the weight control device 27.

Although the above description is for the case where the received signal is an analog signal, it is also possible to perform weighting in the digital signal domain by using an A / D converter or the like.

Next, the weight control device 27 will be described in detail.

Here, in this embodiment, TDMA / SD
Consider the MA system. However, it can be applied to other systems.

As shown in FIG. 4, the initial weight storage device 271 for the control slot of the weight control device 27 sets the coverage area of the base station 1 to n according to the direction viewed from the base station.
N beams (in the example of FIG. 4, the beams B1, B2, and B2) each having the maximum directivity directed to each area (the area A1, the area A2, and the area A3 in the example of FIG. 4). B3) (FIG. 4)
In the example of, weights W1, W2,
Weight W3). In the case of the configuration example of FIG. 3, the weight is a four-dimensional vector.

In the first control slot after the start of the operation of the weight control device 27, the weights W1, W2 and W3 stored in the control slot initial weight storage device 271 are stored by the weight setting device 272.
Weighters 25111 to 251 of beam forming circuit 251
14. Weighting device 252111 of beam forming circuit 252
25214 and weighting device 2 of beam forming circuit 253
5311 to 25314. by this,
Area A is provided to the receiver 261 from the beam forming circuit 251.
1 to provide a reception output from the terminal 3 and a beam forming circuit 2
The receiver output from the terminal 3 in the area A2 can be supplied to the receiver 262 from the area 52, and the receiver output from the terminal 3 in the area A3 can be supplied to the receiver 263 from the beam forming circuit 253. .

The direction estimating device 273 transmits the channel establishment request in the control slot and determines the direction of the terminal 3 that has succeeded by using the reception signals received by the antenna elements 211 to 214 and the reception of the channel establishment request from the terminal 3. Estimation based on the weight information set in the beam forming circuit corresponding to the beamforming device.

When the direction of the terminal 3 is estimated, the correspondence between the identifier information for identifying the terminal 3 and the direction information of the terminal 3 estimated by the direction estimating device 273 is the terminal / direction Correspondence storage device 274 as correspondence information
Is stored.

Weight calculation device for information slot 275
Calculates the weight for forming a beam having the maximum directivity in the direction of the terminal 3 based on the content of the terminal / direction correspondence information stored in the correspondence storage device 274.

The weight calculated by the information slot weight calculating device 275 is the information slot assigned to the terminal 3 and is set by the weight setting device 272 to any one of the beam forming circuits 251 to 253. .

Weight calculation device for control slot 276
Stores the direction of the terminal 3 that has transmitted the channel establishment request detection signal in the information slot with reference to the terminal / direction correspondence information stored in the correspondence storage device 274. Weights Z1 obtained by changing the beam widths of the beams B1, B2, and B3 formed by the weights W1, W2, and W3 stored in the control slot initial weight storage device 271 based on the distribution of the terminals 3 that have transmitted the , Z2, and Z3 are calculated.

The weights Z1, Z2, and Z3 calculated by the control slot weight calculating device 276 are control slots of the next frame, and are weight setting devices 272.
, The weighting device 25111 of the beam forming circuit 251
To 25114, weighting device 25 of beam forming circuit 252
211 to 25214 and the weighters 253111 to 25314 of the beam forming circuit 253, respectively.

Next, the configuration of the direction estimating device 273 will be described in more detail.

FIG. 5 shows an example of the internal configuration of the direction estimating device 273.

The signal arrival direction estimating device 2731 determines the direction of the signal arriving at the control slot by using
２１４ 214 based on the received signals (note that individual terminals are not identified). For specific processing of the DOA estimation, for example, the MUSIC algorithm (M
ultiple Signal Classification) (RO Schmit, “Mult
iple Emitter Location and Signal Parameter Estimat
ion ”, IEEE Trans. Antennas and Propagation, vol.A
P-34, no.3, pp.276-280, March, 1986.) can be used. Of course, other methods may be used.

FIG. 6 shows the direction estimation result of the signal arrival direction estimating device 2731 when the terminals T1, T2 and T3 make a channel establishment request in the control slot SC1 in FIG.

In FIG. 4, the beams B1 and B
2 and B3 correspond to receivers 261,
262, 263. Since there is no terminal requesting channel establishment in beam B1, nothing is output from receiver 261. In addition, the two terminals T1 and T2 in the same beam B2 fail to establish a channel because channel establishment requests collide. Therefore, the terminal identifier information is not output from the receiver 262 either. On the other hand, beam B3
Only the terminal T3 makes a channel establishment request, so that the channel is successfully established. Therefore, the identifier information of the terminal T3 is output from the receiver 263.

The terminal direction estimating device 2732 obtains from the weight setting device 272 that the beam formed by the weight set in the beam forming circuit 253 corresponding to the receiver 263 including the identification information of the terminal T3 is the beam B3. As shown in FIG. 6, the signal arrival direction estimating device 2731
The direction of the peak in the beam B3 in the direction estimation result of the terminal T3 is defined as the direction D3 of the terminal T3, and the identifier information of the terminal T3 and the direction D3 are defined as the terminal / direction correspondence information.
74.

With the above-described configuration, it is possible to estimate the direction of a terminal that has successfully made a channel establishment request in a control slot.

Next, the control slot weight calculation device 2
The configuration of 76 will be described in more detail.

FIG. 7 shows an example of the internal configuration of the control slot weight calculator 276.

The distribution storage device 2761 stores the direction of the terminal 3 that has transmitted the channel establishment request detection signal in the information slot within one frame by referring to the terminal / direction correspondence information stored in the correspondence storage device 274. (See FIG. 13:
FIG. 13 shows information slots ST1 and S1 as described later.
This is an example of the content after the end of T2).

The initial weight changing device 2762 stores the weight stored in the control slot initial weight storage device 271 based on the distribution of the terminals transmitting the channel establishment request detection signal stored in the distribution storage device 2761 after the end of one frame. Calculate n new weights Z1, Z2, and Z3 in which the beam widths of the beams B1, B2, and B3 formed by W1, W2, and W3 are changed to be narrower in a direction where the distribution of terminals is large and widen in a direction where the distribution is small.

Next, a description will be given of an operation procedure of beam control for the communication system of the present embodiment to realize channel establishment with a high success rate.

FIG. 8 shows an example of a processing procedure relating to beam control of the base station 1 (adaptive array 2) in this case. Steps S2 to S4 show a portion corresponding to one information slot.
S4 is repeated for the number of information slots. Steps S2 to S4 may be skipped for an information slot to which no terminal is assigned. Further, as described above, in the first control slot after the start of the operation of the weight control device 27, the initial weight for the control slot is used (step S1). If there is no terminal that has issued a channel establishment request in step S5, for example, the weight at that time may be used, or the initial weight for the control slot may be used.

FIG. 9 shows an example of a procedure relating to beam control when a terminal to which an information slot is allocated receives a channel establishment notice signal from a neighboring terminal.

Here, the information slot ST1 (FIG. 1)
0), beam control in the control slot SC2 (FIG. 14) of the next frame after the information slot ST2 (FIG. 12) ends. As shown in FIG. 10, terminals T4, T5, and T6 are assigned to the information slot ST1 and communicate with the base station 1. As shown in FIG. 12, terminals T7, T8, and T9 are assigned to the information slot ST2, and communicate with the base station 1. As shown in FIG. 14, in the control slot of the next frame, terminals T10,
T11 and T12 make a channel establishment request. Terminal T1
0, T11 and T12 are information slots ST of the previous frame.
1. In ST2, a channel establishment request notice signal is transmitted to notify a terminal to which an information slot has already been allocated that a channel establishment request will be made in the next frame.

Here, an operation procedure in the information slot ST1 (see FIG. 10) will be described.

In the control slot before the information slot ST1, the terminals T4, T5, T6 succeed in channel establishment,
As a result, the information slot ST1 is allocated.

At the same time, the directions of the terminals T4, T5 and T6 are estimated by the direction estimating device 273, and the correspondence between the identifier information of each terminal and the direction information of the terminal is stored in the correspondence storage device 274 as terminal / direction correspondence information. (Step S2). Based on the content of the terminal / direction correspondence information, weights W_T4, W_T5, and W_T4 for forming beams having maximum directivity in the directions of the terminals T4, T5, and T6, respectively.
W_T6 is calculated by the information slot weight calculator 275, and in the information slot ST1, the weight W_T6 is calculated.
T4, W_T5 and W_T6 are assigned to the weight setting device 27.
2, weighting device 25111 of beam forming circuit 251
To 25114, weighting device 25 of beam forming circuit 252
211 to 25214 and weighting units 253111 to 25314 of the beam forming circuit 253 are set (step S3). Thereby, the receiver 261 from the beam forming circuit 251 is provided with the reception output from the terminal T4, the receiver 262 from the beam forming circuit 252 is provided with the reception output from the terminal T5, and the reception from the beam forming circuit 253 is provided. The device 263 can be provided with the reception output from the terminal T6.

The terminal T 6 is connected to the neighboring terminal T 6 by the channel establishment request detecting device 36 via the second transceiver 33.
Since the channel establishment request notice signal is received from step 10 (step S11), a channel establishment request detection signal is transmitted to the base station 1 (step S12).

The channel establishment request notice signal transmitted by terminals T11 and T12 is not received because there is no terminal communicating with base station 1 in the vicinity.

In the distribution storage device 2761 of the weight calculation device for control slot 276, since the signal from the terminal T6 received by the receiver 263 includes the channel establishment request detection signal, it is determined based on the identifier information of the terminal T6. , Referring to the direction of the terminal T6 stored in the correspondence storage device 274,
This direction is stored as the direction in which the channel establishment request was detected (step S4). FIG. 11 shows the information slot ST1.
The content of the distribution storage device 2761 after the end is shown.

Next, the information slot ST2 (see FIG. 12)
Will be described.

Terminals T7, T in information slot ST2
8, T9 also succeeded in channel establishment, and as a result,
An information slot ST2 is allocated.

At the same time, the directions of the terminals T7, T8 and T9 are estimated by the direction estimating device 273, and the correspondence between the identifier information of each terminal and the direction information of the terminal is stored in the correspondence storage device 274 as terminal / direction correspondence information. (Step S2). Based on the contents of the terminal / direction correspondence information, weights W_T7, W_T8, and W_T9 for forming beams having maximum directivity in the directions of the terminals T7, T8, and T9, respectively, are used as information slot weight calculator 275.
In the information slot ST2, the weights W_T7, W_T8, and W_T9 are assigned to the weight setting device 27.
2, weighting device 25111 of beam forming circuit 251
To 25114, weighting device 25 of beam forming circuit 252
211 to 25214 and weighting units 253111 to 25314 of the beam forming circuit 253 are set (step S3). As a result, the receiver 261 from the beam forming circuit 251 receives the reception output from the terminal T7, the receiver 262 from the beam forming circuit 252 receives the reception output from the terminal T8, and the reception from the beam forming circuit 253. The output from the terminal T9 can be given to the device 263.

The terminal T 7 is connected to the neighboring terminal T 7 by the channel establishment request detecting device 36 via the second transceiver 33.
Since the channel establishment request notice signal is received from the base station 1 (step S11), a channel establishment request detection signal is transmitted to the base station 1 (step S12).

The channel establishment request notice signal transmitted by terminals T10 and T12 is not received because there is no terminal communicating with base station 1 nearby.

In the distribution storage device 2761 of the weight calculation device for control slot 276, since the signal from the terminal T7 received by the receiver 261 includes the channel establishment request detection signal, it is determined based on the identifier information of the terminal T7. , With reference to the direction of the terminal T7 stored in the corresponding storage device 274,
This direction is stored as the direction in which the channel establishment request was detected (step S4). FIG. 13 shows the information slot ST2.
The content of the distribution storage device 2761 after the end is shown.

The initial weight changing device 2762 calculates the weight W1 stored in the control slot initial weight storage device 271 based on the distribution in the direction in which the channel establishment request is stored stored in the distribution storage device 2761 after the end of one frame. , W2, W3 form beams B1, B
2. A new weight Z1 for forming n beams in which the beam width of B3 (see FIG. 4) is changed to be narrower in the direction of more distribution and wider in the direction of lower distribution.
Z2 and Z3 are calculated (step S5).

Next, the control slot SC2 (see FIG. 14)
Will be described.

The terminals T10, T11 and T12 make a channel establishment request.

On the other hand, the control slot weight calculating device 2
Weights Z1, Z2 and Z3 calculated by 76
Is the beam forming circuit 25 by the weight setting device 272.
1 weighters 25111 to 25114, 2521 to 25214 of the beam forming circuit 252, and 253111 to 2531 of the beam forming circuit 253.
4 (the corresponding areas are E1, E2, E
3) (Step S6).

Thus, the reception output from the terminal T11 in the area E1 is given to the receiver 261 from the beam forming circuit 251 and the receiver 26 from the beam forming circuit 252 is received.
2, the reception output from the terminal T12 in the area E2 can be given, and the reception output from the terminal T10 in the area E3 can be given to the receiver 263 from the beam forming circuit 253. Therefore, the terminals T10, T11, T
12 succeeds in channel establishment.

In this way, the direction of the terminal requesting channel establishment is estimated in advance, and
By forming a beam with a narrow beam width in the direction in which it is estimated that many terminals request channel establishment, it is possible to prevent multiple terminals from entering the same beam and reduce the rate of channel establishment failure. (Can achieve a high success rate channel establishment).

(Second Embodiment) This embodiment is basically the same as the first embodiment, and therefore, the following description will focus on the points of difference between the second embodiment and the first embodiment. .

FIG. 15 shows a configuration example of a terminal according to the present embodiment. As shown in the terminal configuration example of FIG. 15, the present embodiment is different from the first embodiment in that a terminal reception power measuring device 37 is added to the terminal configuration example of FIG. 2 of the first embodiment. That is the point.

FIG. 16 shows an example of a procedure related to beam control when a terminal to which an information slot is assigned receives a channel establishment announcement signal from a neighboring terminal in this case. An example of a processing procedure related to beam control of the base station 1 (adaptive array 2) in this case is the same as that in FIG.

The terminal reception power measuring device 37 allows a terminal to which an information slot has already been allocated to transmit a channel establishment request notice signal from a nearby terminal by a channel establishment request detecting device 36 through a second transceiver 33. If received (step S21), the signal strength of the received signal is measured. If the measured signal strength is equal to or more than a predetermined value (step S22), the channel establishment request detection signal is transmitted to the base station in the assigned information slot. The data is transmitted to the station 1 (step S23).

As described above, by ignoring the channel establishment request announcement signal whose received power is less than the predetermined value, a channel establishment request detection signal corresponding to the channel establishment request announcement signal from a terminal at a long distance is transmitted to base station 1. Transmission can be prevented. Therefore, the distribution in the direction in which the establishment request is stored, which is stored by the distribution storage device 2761 of the control slot weight calculation device 276, becomes accurate.

(Third Embodiment) The present embodiment is basically the same as the first embodiment, and therefore, the following description will focus on the differences between the present embodiment and the first embodiment. .

FIG. 17 shows a configuration example of a terminal according to the present embodiment. FIG. 18 shows a configuration example of a control slot weight calculation device of the adaptive array weight control device according to the present embodiment.

As shown in the terminal configuration example of FIG.
This embodiment differs from the first embodiment in that an identifier notice device 38 and an identifier detection device 39 are added to the configuration example of the terminal in FIG. As shown in the configuration example of the weight calculation device, the first
Weight calculation device 2 for the control slot of FIG.
This is the point that the duplication preventing device 2763 is added to the configuration example of the 76.

FIG. 19 shows an example of a procedure relating to beam control when a terminal to which an information slot is allocated receives a channel establishment announcement signal from a neighboring terminal in this case. An example of a processing procedure regarding beam control of the base station 1 (adaptive array 2) in this case is basically the same as that in FIG. 8 (however, it is assumed that the same identifier is not redundantly processed in step S4).

When the terminal sends a channel establishment request notice signal, the identifier notice device 38 adds an identification notice signal containing identifier information of the terminal and transmits the signal.

The identifier detection device 39 is used when a terminal to which an information slot has already been assigned receives a channel establishment request notice signal from a neighboring terminal by the channel establishment request detection device 36 via the second transceiver 33. In step S31, when an identifier advance notice signal is also received (step S32), a channel establishment request detection signal and a detected identifier advance notice signal are transmitted to the base station 1 in the assigned information slot (step S33). . On the other hand, when the identifier advance notice signal is also received (step S32), a channel establishment request detection signal is transmitted to the base station 1 in the assigned information slot (step S33).

The duplication preventing apparatus 2763 includes, in the signal from the terminal received by the receiver in the information slot, an identifier including the same identifier information as that contained in the identifier advance notice signal already received in the same slot. When the notice signal is included, the signal from the receiver at this time is not input to the distribution storage device 2761.

By doing so, it is possible to prevent a channel establishment request detection signal corresponding to a channel establishment request notice signal from the same terminal from being input to the distribution storage device 2761 within the same frame. Therefore, the distribution in the direction in which the establishment request is stored, which is stored by the distribution storage device 2761 of the control slot weight calculation device 276, becomes accurate.

In the above description, the terminal may or may not receive the identifier advance notice signal together with the channel establishment request advance notice signal from the neighboring terminal (the neighbor terminal transmits the identifier advance notice signal together with the channel establishment request advance notice signal). The neighbor terminal always transmits the identifier notice signal together with the channel establishment request notice signal, and receives the identifier notice signal together with the channel establishment request notice signal from this neighboring terminal. The terminal may transmit the identifier advance notice signal to the base station 1 together with the channel establishment request advance notice signal.

As described above, when the identifier of the terminal making the channel establishment request has already been received in the same frame, the signal from the receiver at this time is stored in the distribution storage device 2761. By not inputting, it is possible to prevent duplication of a channel establishment request notice signal from the same terminal in the same frame. Therefore, the distribution storage device 2 of the control slot weight operation device 276
The distribution in the direction in which the establishment request is stored, which is stored by 761, becomes accurate.

The configuration of the third embodiment is further modified by a second
It is also possible to combine and implement the configurations of the above embodiments.

The present invention is applicable not only to mobile communication systems but also to FWAs (Fixed Wireless Ac).
ses) system.

Note that each of the above functions can be realized as software. Further, the above functions, devices, or systems are implemented as a program for causing a computer to execute predetermined means (or for causing a computer to function as predetermined means, or for causing a computer to realize predetermined functions). The present invention can also be implemented as a computer-readable recording medium on which the program is recorded.

The configuration illustrated in the embodiment of the present invention is merely an example, and is not intended to exclude other configurations. Some of the illustrated configurations may be replaced with other configurations or illustrated. Another configuration obtained by omitting a part of the configuration, adding another function or element to the illustrated configuration, or combining them is also possible. Also, another configuration that is logically equivalent to the illustrated configuration,
Another configuration including a portion logically equivalent to the illustrated configuration, another configuration logically equivalent to a main part of the illustrated configuration, and the like are also possible. Further, another configuration that achieves the same or similar purpose as the illustrated configuration, another configuration that achieves the same or similar effect as the illustrated configuration, and the like are also possible. Various variations of the various components exemplified in the embodiments of the present invention can be implemented in appropriate combinations. Further, the embodiments of the present invention relate to an invention as an individual device, an invention about two or more related devices, an invention as a whole system, an invention about components inside an individual device, or a method corresponding thereto. It encompasses and includes inventions related to various aspects, stages, concepts or categories, such as inventions. Therefore, the present invention can be extracted from the contents disclosed in the embodiments of the present invention without being limited to the illustrated configuration.

The present invention is not limited to the above-described embodiment, but can be implemented with various modifications within the technical scope.

[0097]

According to the present invention, the radio communication system notifies the radio communication system in advance that a channel establishment request is to be made through a terminal currently communicating with the radio communication system, so that the radio communication system can change the direction of the terminal requesting the channel establishment. By estimating in advance and forming a beam according to the distribution of terminals, it is possible to prevent a plurality of terminals from entering the same beam in a control slot, and reduce the rate of channel establishment failure.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration example of a wireless communication system according to an embodiment of the present invention.

FIG. 2 is a diagram showing a configuration example of a terminal according to the embodiment.

FIG. 3 is a diagram showing a configuration example of an adaptive array provided in the base station according to the embodiment.

FIG. 4 is a diagram showing an example of a terminal position and a beam shape in a control slot SC1.

FIG. 5 is a diagram showing an example of an internal configuration of a direction estimation device according to the embodiment;

FIG. 6 is a diagram showing an example of a direction estimation result of the signal arrival direction estimation device according to the embodiment.

FIG. 7 is a diagram showing an example of the internal configuration of a control slot weight calculation device according to the embodiment;

FIG. 8 is a flowchart showing an example of a processing procedure regarding beam control of an adaptive array provided in the base station according to the embodiment.

FIG. 9 is a flowchart showing an example of a procedure related to beam control when the terminal according to the embodiment receives a channel establishment announcement signal from a neighboring terminal.

FIG. 10 is a diagram showing an example of a terminal position and a beam shape in an information slot ST1.

FIG. 11 is a diagram showing an example of the contents of the distribution storage device after the end of the information slot ST1.

FIG. 12 is a diagram showing an example of a terminal position and a beam shape in an information slot ST2.

FIG. 13 is a diagram showing an example of the contents of the distribution storage device after the end of the information slot ST2.

FIG. 14 is a diagram showing an example of a terminal position and a beam shape in a control slot SC2.

FIG. 15 is a diagram showing another configuration example of the terminal according to the embodiment.

FIG. 16 is a flowchart showing another example of the procedure related to beam control when the terminal according to the embodiment receives a channel establishment announcement signal from a neighboring terminal.

FIG. 17 is a diagram showing still another configuration example of the terminal according to the embodiment.

FIG. 18 is a diagram showing a configuration example of a control slot weight calculation device of the weight control device according to the embodiment;

FIG. 19 is a flowchart showing still another example of the procedure related to beam control when the terminal according to the embodiment receives a channel establishment announcement signal from a neighboring terminal.

FIG. 20 is a diagram showing space division multiplexing in a conventional wireless communication system.

FIG. 21 is a diagram showing a configuration of an adaptive array when the number of multiplexing is 3 in a conventional wireless communication system.

FIG. 22 is a diagram showing a terminal position and a beam shape in a control slot in a conventional wireless communication system.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Base station 2 ... Adaptive array 211-214 ... Antenna element 221-224 ... Amplifier (low noise amplifier) 231-234 ... Frequency converter 241-244 ... Divider 251-253 ... Beam forming circuit 25111-11-25114, 252111 25214,2
5311 to 25314 weighting devices 2512, 2522, 2532 synthesizers 261, 262, 263 receiver 27 weight control device 271 initial weight storage device for control slot 272 weight setting device 273 direction estimation device 2731 signal arrival Direction estimating device 2732 ... terminal direction estimating device 274 ... corresponding storage device 275 ... weight calculation device for information slot 276 ... weight calculation device for control slot 2761 ... distribution storage device 2762 ... initial weight changing device 2763 ... duplication prevention device 3 ... terminal 31 ... first transceiver 32 ... first antenna 33 ... second transceiver 34 ... second antenna 35 ... channel establishment request notice device 36 ... channel establishment request detection device 37 ... terminal received power measurement device 38 ... identifier notice Device 39 ... Identifier detection device

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5K022 FF00 5K059 CC04 DD32 5K067 AA25 CC01 CC05 CC06 CC24 DD11 DD17 EE02 FF02 HH23 KK02 KK03 KK15

Claims (14)

[Claims] A wireless communication system capable of simultaneously communicating with a plurality of terminals by space division multiplexing, wherein a predetermined number of antenna elements and a reception signal received by the plurality of antenna elements are weighted and combined. Outputting a reception signal corresponding to a beam having a directivity pattern, a plurality of beam forming means, and a control means for setting a weight vector for controlling the weighting synthesis for each of the plurality of beam forming means, Collecting means for collecting information indicating a direction of a second terminal for notifying the own system of the presence of a first terminal for notifying a request for channel establishment in an information slot;
Generating means for generating the plurality of weight vectors in the next control slot based on the distribution of the direction of the second terminal collected during one frame by the means. . 2. The method according to claim 1, wherein the generating unit is configured such that, with respect to the beam widths of the plurality of beams used in the control slot, the beam width of the formed beam decreases as the distribution of the second terminals increases. The wireless communication system according to claim 1, wherein the plurality of weight vectors in the control slot are generated such that a beam width of a beam formed increases in a direction in which the distribution of terminals is smaller. 3. An initial weight vector for forming a plurality of beams having maximum directivity to each area formed by equally dividing a cover area of the own system according to a direction viewed from a position of the own system. 2. An apparatus according to claim 1, wherein each area is stored, and in a control slot for the first time after the start of its own operation, each initial weight vector is set in the corresponding beam forming means.
A wireless communication system according to claim 1. 4. The control means sets a direction of a terminal that has made a channel establishment request in a control slot and succeeded in a signal received by a plurality of the antenna elements and in the beam forming means corresponding thereto at that time. Estimating means for estimating based on the weight vector, and means for generating the plurality of weight vectors in the information slot so as to form beams each having the maximum directivity in the direction estimated for each terminal. The wireless communication system according to claim 1, further comprising: 5. An estimating means for estimating a direction of a signal arriving at a control slot on the basis of signals received by the plurality of antenna elements. The weight set in the beam forming means for outputting a signal from a terminal that has
The radio communication system according to claim 4, further comprising means for estimating a direction in a beam formed by the vector as a direction of the terminal for which the channel has been successfully established. 6. A signal notifying the presence of the first terminal,
2. The wireless communication device according to claim 1, wherein the second terminal, which has received the channel establishment request notice signal from a neighboring terminal, transmits the signal using an information slot allocated to the second terminal. A wireless communication system according to claim 1. 7. The second terminal is assigned to its own terminal only when receiving the channel establishment request notice signal from the neighboring terminal and only when the intensity of the received signal is equal to or higher than a predetermined value. The wireless communication system according to claim 6, wherein the signal for notification is transmitted to the wireless communication system using an information slot. 8. The second terminal, when receiving the channel establishment request notice signal from the neighboring terminal, and when also receiving the identifier notice signal, changes the information slot allocated to the terminal itself. While transmitting the signal for notification to the wireless communication system using the same, also transmits a signal for notification of the identifier together, the collection unit refers to the received identifier, the same identifier 7. The wireless communication system according to claim 6, wherein the notification of the presence of the first terminal accompanied by (c) is reflected only once in the distribution even if the notification is received repeatedly. 9. The transmission of the channel establishment request notice signal from the first terminal to the second terminal is performed by local radio communication provided separately from radio communication means used between the terminal and the radio communication system. The wireless communication system according to any one of claims 6 to 8, wherein the wireless communication system is performed by means. 10. The transmission of the channel establishment request notice signal from the first terminal to the second terminal is performed by wireless communication means used between the terminal and a wireless communication system. Item 9. The wireless communication system according to any one of Items 6 to 8. 11. An adaptive array having a plurality of beam forming means for outputting received signals corresponding to beams having a predetermined directivity pattern by weighting and combining received signals received by a plurality of antenna elements. A weight vector control device, comprising: a setting unit for setting a weight vector for controlling the weighted combination for each of the plurality of beam forming units; and a setting unit for setting each of the beam forming units in an information slot. First generating means for generating the weight vector, and second generating means for generating the weight vector to be set for each of the beam forming means in a control slot, the second generating means The means determines the presence of a first terminal foretelling a request for channel establishment in the information slot. Information indicating the direction of the second terminal to be notified to the own system is collected, and based on the distribution of the direction of the second terminal collected during one frame, a plurality of the weight vectors in the next control slot are calculated. A weight vector control device characterized by generating. 12. A weight vector for controlling a weighted combination when obtaining a received signal corresponding to a beam having a predetermined directivity pattern by weighting and combining received signals received by a plurality of antenna elements. A method for generating a weight vector, comprising: collecting information indicating a direction of a second terminal for notifying the own system of the presence of a first terminal for announcing a request for channel establishment in an information slot; A weight vector generation method, comprising: generating a plurality of weight vectors in a next control slot based on the collected distribution of directions of the second terminal. 13. An adaptive array having a plurality of beam forming circuits for outputting received signals corresponding to beams having a predetermined directivity pattern by weighting and combining received signals received by a plurality of antenna elements. A program for causing a computer to function as a weight vector control device, which collects information indicating the direction of a second terminal that notifies its own system of the presence of a first terminal that notifies a channel establishment request in an information slot. And a function of causing the computer to generate a plurality of the weight vectors in the next control slot based on the distribution of directions of the second terminal collected during one frame. 14. A terminal device capable of communicating with a wireless communication system capable of simultaneously communicating with a plurality of terminals by space division multiplexing, comprising: a first transmitting / receiving means for communicating with said wireless communication system. A second transmitting / receiving means for performing communication with a neighboring terminal; generating a channel establishment request notice signal when making a channel establishment request in a control slot; In a frame immediately before the frame for which a request is made, a channel establishment notifying unit that notifies a nearby terminal via the second transmitting / receiving unit, and a channel establishment request notifying signal is detected via the second transmitting / receiving unit. A channel for transmitting a channel establishment request detection signal to the wireless communication system via the first transmission / reception means in an information slot allocated to the terminal. A terminal device comprising: a channel establishment request detecting unit.