JP2003078472A - Radio base station device, and method and program for controlling transmission directivity - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radio base station device and a transmission directivity controlling method, and a transmission directivity control program, capable of maintaining spatial multiple connection without deteriorating the receiving performance of a diversity terminal. SOLUTION: In an adaptive array base station 1000, a user signal processing part 50 transmits radio waves having transmission directivity to a desired terminal with adaptive array processing for a plurality of antennas 11 and 12. Further, the user signal processing part 50 changes the transmission directivity to the diversity terminal device only for a prescribed period in accordance with the results obtained by deciding whether or not a connected terminal device is the diversity terminal device.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a radio base unit,
TECHNICAL FIELD The present invention relates to a transmission directivity control method and a transmission directivity control program, and in particular, in a mobile communication system communicating with a plurality of diversity terminals, a radio base apparatus capable of maintaining spatial multiplex connection, a transmission directivity control method, and The present invention relates to a transmission directivity control program.

[0002]

2. Description of the Related Art In recent years, in mobile communication systems (for example, Personal Handyphone System: PHS) which are rapidly developing, the same time slot of the same frequency is spatially arranged in order to increase the frequency utilization efficiency of radio waves. By dividing, it is possible to spatially multiplex the wireless terminal devices (terminals) of a plurality of users to the wireless base station (base station).
A DMA (Path Division Multiple Access) method has been proposed.

In this PDMA system, an adaptive array technique is adopted, and an upstream signal from an antenna of each user terminal is received by an array antenna of a base station and separated and extracted with a receiving directivity by an adaptive array processing. . On the other hand, a downlink signal from the base station to the terminal is transmitted from the array antenna with transmission directivity for the antenna of the terminal.

Such adaptive array processing is a well-known technique. For example, reference 1: No. 3 Kikuma's "Adaptive Signal Processing by Array Antenna" (Science and Technology Publication), pp. 35-49, "3. Since it is described in detail in "Chapter MMSE Adaptive Array", the explanation of its operation principle is omitted here.

In the following description, a base station that performs downlink transmission directivity control for a terminal using such an adaptive array process is referred to as an "adaptive array base station".

On the other hand, as a terminal, there is known one that performs selective diversity reception (hereinafter referred to as "diversity reception") using a plurality of antennas. As such a terminal, one having two built-in antennas called a whip antenna and a chip antenna is generally incorporated, and such a terminal is hereinafter referred to as a "diversity terminal". A terminal with one antenna that does not perform diversity reception is called a normal terminal.

Such a diversity terminal normally has one antenna (generally a whip antenna) at the time of transmission.
Is fixed as a transmission antenna, and at the time of reception, an antenna having a higher reception level of the whip antenna and the chip antenna is selected as a reception antenna.

Such a diversity terminal, regardless of whether the connected base station is an adaptive array base station for controlling transmission directivity or an omnidirectional base station other than that, It is common to perform diversity reception.

FIG. 8 is a diagram schematically showing a connection state between a terminal and a base station, and particularly, the adaptive array base station 1
In contrast, two diversity terminals U1 and U2
It is a figure which shows typically the state which is carrying out the spatial multiple connection by the adaptive array process.

Referring to FIG. 8, diversity terminal U1
At the time of transmission, the whip antenna 2a fixed as a transmitting antenna transmits an upstream signal, and the adaptive array base station 1 receives this at the array antenna 1a.

On the other hand, also in the diversity terminal U2, at the time of transmission, the whip antenna 3 to which the transmission antenna is fixed is fixed.
The uplink signal is transmitted by a, and the adaptive array base station 1
Receives this with the array antenna 1a.

On the other hand, from the adaptive array base station 1, the directivity indicated by the solid line (corresponding to the transmission power level)
Then, the downlink signal to the diversity terminal U1 is transmitted,
The downlink signal to the diversity terminal U2 is transmitted with the directivity (corresponding to the transmission power level) indicated by the broken line.

Regarding the transmission directivity for the diversity terminal U1, the beam is directed to the whip antenna 2a which transmits the upstream signal of the diversity terminal U1 and the null is directed to the antenna 3a of the diversity terminal U2 which is an interference source.

On the other hand, regarding the transmission directivity with respect to the diversity terminal U2, the beam is directed to the antenna 3a which transmits the upstream signal of the diversity terminal U2, and the null is directed to the whip antenna 2a of the diversity terminal U1 which is an interference source. To be

As a result, the signal received by the antenna 2a of the diversity terminal U1 is downlinked from the adaptive array base station 1 to the diversity terminal U2 with respect to the downlink signal level (solid line) from the adaptive array base station to the diversity terminal U1. The signal level (broken line) is relatively small, and the signal has a small interference component, that is, a signal having a high DU ratio. The same applies to the diversity terminal U2.

[0016]

By the way, as described above, in the diversity terminal, the whip antenna is fixed as the transmitting antenna, and at the time of reception, the antenna having the higher receiving level of the whip antenna and the chip antenna is selected as the receiving antenna. To work.

Here, paying attention to the chip antenna 2b of the diversity terminal U1, this antenna is not used for transmitting the upstream signal, and therefore, the null of the transmission directivity (broken line) to the diversity terminal U2 is directed. Absent.

Therefore, the chip antenna 2b of the diversity terminal U1 receives not only the transmission power for the diversity terminal U2 (solid line), but also the transmission power for the diversity terminal U2 (broken line), and the reception at the chip antenna 2b. Level is whip antenna 2
There is a possibility that the chip antenna 2b will be selected as the receiving antenna, exceeding the transmission level in a.

If the chip antenna 2b is selected as the receiving antenna, the adaptive array base station 1
From the adaptive terminal U2 to the diversity terminal U2 (solid line), the downlink signal level from the adaptive array base station 1 to the diversity terminal U2 (broken line) becomes relatively large, and a signal with a large DU ratio with a large interference component is obtained. turn into.

Even if the diversity terminal U1 attempts to demodulate such a received signal having a low DU ratio, a frame error of the demodulated signal occurs, and there is a high possibility that accurate demodulation cannot be performed.

As described above, in a mobile communication system in which a plurality of diversity terminals exist within the service area of the adaptive array base station, when a plurality of diversity terminals are spatially multiplexed connected to the adaptive array base station, The DU ratio in the diversity terminal decreases, and the reception performance deteriorates due to the interference wave.

As a result, there is a problem that the diversity terminal cannot maintain the spatial multiplex connection.

Therefore, an object of the present invention is to maintain spatial multiplex connection in a mobile communication system in which a plurality of diversity terminals and base stations are spatially multiplex connected, without degrading the reception performance of the diversity terminals. A radio base station, a transmission directivity control method, and a transmission directivity control program are provided.

[0024]

A radio base apparatus according to claim 1 is a radio base apparatus in a mobile communication system, wherein the mobile communication system performs diversity reception capable of spatial multiplex connection to the radio base apparatus. Including a plurality of diversity terminal device to perform, the wireless base device, a plurality of antennas, adaptive array processing means for transmitting a radio wave having a transmission directivity to a desired terminal by adaptive array processing for the plurality of antennas, and a wireless A terminal type determination unit that determines whether or not the terminal device connected to the base unit is a diversity terminal device, and the transmission directivity for the diversity terminal device is changed only for a predetermined period according to the determination result by the terminal type determination unit. And a transmission directivity control means.

A radio base unit according to a second aspect is the first aspect.
In addition to the configuration of the wireless base device described, the signal exchanged between the wireless base device and the diversity terminal device is composed of a plurality of slots, each slot is communicated with a preamble section consisting of a known signal sequence. The transmission directivity control means detects that the transmission signal to and from the diversity terminal device is a preamble section, and changes the transmission directivity only in the preamble section.

The radio base unit according to claim 3 is the same as that according to claim 1.
Alternatively, in addition to the configuration of the wireless base device described in 2, the terminal type determination device includes means for evaluating downlink signal reception performance in a terminal device connected to the wireless base device and quality of an upstream signal from the terminal device. And a means for determining the terminal device as a diversity terminal device when it is evaluated that the downlink signal reception performance is low and the uplink signal quality is good.

According to a fourth aspect of the present invention, there is provided a transmission directivity control method, wherein in a mobile communication system, adaptive array processing for a plurality of antennas transmits a radio wave having a transmission directivity to a desired terminal. The directivity control method, the mobile communication system includes a plurality of diversity terminal device performing spatial diversity connection to the radio base device, the transmission directivity control method, connecting to the radio base device. It comprises a step of determining whether or not the existing terminal device is a diversity terminal device, and a step of changing the transmission directivity for the diversity terminal device for a predetermined period according to the determination result.

According to a fifth aspect of the transmission directivity control method, in addition to the configuration of the transmission directivity control method according to the fourth aspect, a plurality of signals are exchanged between the radio base station and the diversity terminal. Each slot includes a preamble section including a known signal sequence and a data section including data to be communicated, and the step of changing the transmission directivity is performed by the preamble of the transmission signal with the diversity terminal device. The step of detecting the section and changing the transmission directivity only in the preamble section is included.

According to a sixth aspect of the transmission directivity control method, in addition to the configuration of the fourth aspect of the transmission directivity control method, the step of determining is a downlink in a terminal device connected to a radio base apparatus. A step of evaluating the signal reception performance and the quality of the uplink signal from the terminal device, and determining the terminal device as a diversity terminal device when the reception performance of the downlink signal is low and the quality of the uplink signal is evaluated to be good. And steps.

According to a seventh aspect of the present invention, there is provided a transmission directivity control program for an adaptive array radio base station for transmitting a radio wave having a transmission directivity to a desired terminal by adaptive array processing for a plurality of antennas in a mobile communication system. The transmission directivity control program of claim 1, wherein the mobile communication system includes a plurality of diversity terminal devices for performing diversity reception capable of performing spatial multiplex connection to the radio base device, and the transmission directivity control program is stored in a computer. A step of determining whether or not the terminal device connected to the device is a diversity terminal device, and a step of changing the transmission directivity for the diversity terminal device for a predetermined period according to the determination result are executed.

According to the transmission directivity control program of claim 8, in addition to the configuration of the transmission directivity control program of claim 7, a plurality of signals are exchanged between the radio base unit and the diversity terminal device. Each slot includes a preamble section including a known signal sequence and a data section including data to be communicated, and the step of changing the transmission directivity is performed by the preamble of the transmission signal with the diversity terminal device. The step of detecting the section and changing the transmission directivity only in the preamble section is included.

In addition to the configuration of the transmission directivity control program according to claim 7 or 8, the transmission directivity control program according to claim 9 includes the step of determining in the downlink in the terminal device connected to the radio base apparatus. A step of evaluating the signal reception performance and the quality of the uplink signal from the terminal device, and determining the terminal device as a diversity terminal device when the reception performance of the downlink signal is low and the quality of the uplink signal is evaluated to be good. And steps.

[0033]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will now be described in detail with reference to the drawings. In the drawings, the same or corresponding parts will be denoted by the same reference characters and description thereof will not be repeated.

FIG. 1 is a conceptual diagram schematically showing the principle of the transmission power and its transmission directivity control according to the present invention. More specifically, first, it is assumed that diversity terminal U1 (not shown) is connected to the adaptive array base station. In such a state, as in the case of FIG. 8 described above, when the diversity terminal U2 performs spatial multiplex connection to the adaptive array base station by using adaptive array processing, desired waves and interference waves in the diversity terminal U2 The state is schematically shown in FIG.

The spatial multiple connection state shown in FIG. 1 differs from the state shown in FIG. 8 in the following points.

That is, the adaptive array base station is
When the diversity terminal U2 decides which one of the chip antenna and the whip antenna should be used as the receiving antenna, the directivity which has been transmitted up to that time with the diversity terminal U1 is destroyed, in other words, the phase of the transmitting directivity is shifted. Then, the whip antenna 3 of the diversity terminal U2
With respect to a, a transmission directivity that intentionally raises the level of the interference wave is realized.

As a result, the reception power of the whip antenna 3a of the diversity terminal U2 can be increased as compared to the case where the transmission directivity is not changed. Therefore, the whip antenna 3a is more likely to be selected as the receiving antenna instead of the chip antenna 3b.

That is, first, before breaking such directivity, the "received power of the whip antenna" and the "received power of the chip antenna" are expressed as follows.

(Reception power of whip antenna) = (Beam of desired wave) (Reception power of chip antenna) = (Side lobe of desired wave) + (Side lobe of interference wave) On the other hand, as described above, When the process of destroying the transmission directivity is performed, “the received power of the whip antenna” and “the received power of the chip antenna” are expressed as “interference wave ′” when the interference wave when the process of destroying the transmission directivity is expressed as Is changed to.

(Reception power of whip antenna) = (Beam of desired wave) = (Side lobe of interference wave ') (Reception power of chip antenna) = (Side lobe of desired wave) + (Side lobe of interference wave') Note that the above-mentioned "when the diversity terminal determines which one of the chip antenna and the whip antenna is the receiving antenna" is the "preamble section" of the transmission signal from the adaptive array base station as described later.
Is.

In this way, after the transmission directivity from the adaptive array base station is destroyed in the "preamble section",
In the data section necessary for the terminal side such as demodulation, processing for returning to the original transmission directivity is performed.

By performing such processing, it is possible to improve the success probability of spatial multiplexing.

FIG. 2 is a schematic block diagram showing the configuration of adaptive array base station 1000 according to the embodiment of the present invention for performing the transmission directivity control described with reference to FIG.

Referring to FIG. 2, adaptive array base station 1000 has an array antenna composed of a plurality of antennas, for example, antennas 11 and 12.

The antennas 11 and 12 are connected to the radio units 21 and 22, respectively. The wireless units 21 and 22 have exactly the same configuration, and only the configuration of the wireless unit 21 will be shown and described.

The radio section 21 includes a switch 110, a transmission section 111, a reception section 112, a D / A converter 113, and an A / D converter.
And a D converter 114.

At the time of reception, the switch 110 is switched so that the signal received by the antenna 11 is given to the receiving section 112. The received signal given to the receiving unit 112 is subjected to various kinds of analog signal processing such as amplification and frequency conversion, converted into a digital signal by the A / D converter 114, and given to the user signal processing unit 50.

The user signal processing section 50 separates and extracts the signal of each user by the adaptive array processing described later. The separated and extracted received signals of each user are processed by the normal modem unit 60 and the baseband processing and TDMA / TD.
The signal is supplied to the D processing unit 70, subjected to necessary demodulation processing and time-division processing, restored to the original signal, and the public network 9
Supplied to zero.

On the other hand, at the time of transmission, the transmission signal given from the public network 90 is subjected to baseband processing and TDMA.
/ TDD processing section 70 and modem section 60 are provided with the necessary time division processing and modulation processing, and then provided to user signal processing section 50.

In the user signal processing section 50, the downlink transmission directivity is controlled and the D of the radio section 21 is controlled, as will be described later.
It is converted into an analog signal by the / A converter 113.

The transmission signal converted into an analog signal is subjected to various kinds of analog signal processing necessary for radio transmission, such as amplification and frequency conversion, in the transmission section 111.

At the time of transmission, the switch 110 has the transmitting unit 1
The transmission signal is switched to connect the antenna 11 and the antenna 11, and the transmission signal radio-processed by the transmission unit 111 is transmitted from the antenna 11.

Basically, similar processing is executed also via the radio section 22, and the antennas 11 and 12 send out radio waves having a transmission directivity which has been subjected to the adaptive array processing.

The adaptive array base station 1 shown in FIG.
000 includes a control unit 80, and the control unit 80 determines the type of the terminal based on the information from the modem unit 60 and the baseband processing and TDMA / TDD processing unit 70 according to a procedure described later. "Diversity terminal determination unit" for determining, "multiplex determination unit" for determining whether multiple connections are performed, and "communication period" for determining whether the current communication signal is a "preamble period" And a “determination unit” is provided.

The operation of the controller 80 will be described later in detail. FIG. 3 is a conceptual diagram for explaining a configuration of signals transmitted and received between adaptive array base station 1000 and a terminal.

A signal of one frame is divided into 8 slots, the first 4 slots are for transmission and the latter 4 are for example.
The slot is for reception, for example.

In the example shown in FIG. 3, one frame signal is assigned to 3 or 4 users with one receiving slot and one transmitting slot as one set.

It is assumed that each frame includes a unique word signal (reference signal) section and is capable of error detection (CRC: cyclic redundancy check) by a cyclic code. The adaptive array base station 1000 has a unique word signal stored in advance,
Weight vector control (determination of weighting factors for adaptive array processing) is performed so as to compare with the received signal sequence and extract a signal that seems to include a signal sequence corresponding to a specific user.

Here, in the case where the mobile terminal devices of a plurality of users are path-multiplexed in the same time slot, in order to identify each user by shifting the reception timing of the reception signal from each mobile terminal device. It is assumed that the transmission timing from the base station 1000 to each terminal is shifted from the reference transmission timing.

FIG. 4 is a conceptual diagram for explaining the configuration of the transmission / reception signal shown in FIG. 3 in more detail.

Referring to FIG. 4, one frame (5 mse
During c), four slots for transmission and four subsequent slots for reception are included.

One slot for transmission consists of a signal of 120 symbols (240 bits). This one slot is
The head part includes a known signal sequence, and subsequently includes a data signal such as voice.

As the "known signal sequence", the ramp portion R, the start symbol SS, the preamble signal PR for synchronizing with the terminal at the beginning, and the reference signal for performing the adaptive array processing are provided. It includes a unique word UW used as, a signal CI indicating a channel type, and the like.

In FIG. 4, a control slot is a slot for exchanging data between a terminal and a base station during a period for establishing a telephone call, and a communication slot is for each terminal. This is a slot for exchanging signals for communication with the base station.

The slot on the receiving side basically has the same structure, and the receiving slot consists of a section consisting of a known signal sequence and a section containing data such as voice.

Here, in the present invention, the "preamble section" for performing the processing for increasing the probability that the whip antenna is selected in the diversity terminal by shifting the transmission directivity means the above-mentioned data section in the frame format. Of the "known signal sequence" that exists in front of, and is used for synchronization, etc., means the "interval where reception error itself is recognized as a premise" on the communication protocol. . For example, PHS
In the frame format of, the “preamble signal section (PR)” in FIG. 4 corresponds to such a “preamble section”.

Therefore, even if a reception error occurs in such a "preamble section", the system does not judge that an error occurs in the communication state. That is,
On the contrary, even if the processing for deteriorating the transmission directivity is performed in such a "preamble section", it does not affect the maintenance of the call state.

FIG. 5 shows the user signal processing unit 5 shown in FIG.
It is a functional block diagram which shows the structure of 0.

The user signal processing section 50 shown in FIG.
The processing of the control unit 80 is actually realized by software using a digital signal processor (DSP).

Referring to FIG. 5, user signal processing unit 50
Is composed of a user A signal processing unit 50a and a user B signal processing unit 50b.

User A signal processor 50a and user B
The signal processing unit 50b has exactly the same configuration, and only the configuration of the user A signal processing unit 50a will be illustrated and described.

A radio section 21 corresponding to the antenna 11 of FIG.
Of the digital signal received from the receiving section 112 of the wireless unit 22 via the A / D converter 114 and the digital signal of the receiving section (not shown) of the wireless unit 22 corresponding to the antenna 12 via the A / D converter (not shown). The received signal is user A
It is commonly given to the signal processing unit 50a and the user B signal processing unit 50b.

The processing of these digital signals supplied to the user A signal processing section 50a will be described below.

These signals supplied to the user A signal processor 50a are adaptively array-processed by software in the base station 1000 according to the functional block diagram shown in FIG.

Referring to FIG. 5, the received signal vector composed of the two systems of digital received signals given from the radio units 21 and 22 to the user A signal processing unit 50a is the multiplier MR1,
It is given to each one input of MR2, and is given to the reception weight vector calculator 52a.

The reception weight vector calculator 52a calculates a weight vector composed of weights for each antenna by an adaptive array algorithm described later,
Apply to the other input of each of the multipliers MR1 and MR2,
Complex multiplication is performed with the received signal vector from the corresponding antenna. The adder AD1 obtains an array output signal which is the sum of the complex multiplication results.

The array output signal, which is the result of the complex multiplication sum as described above, is demodulated into bit data and error-determined by the demodulation and error determination unit 51a, and is then separated and extracted from the received signal from the user A. Is supplied to the modem unit 60 of FIG.

Similarly, the user B signal processing unit 50b supplies the separated and extracted received signal from the user B to the modem unit 60.

In the reception weight vector calculator 52a,
RLS (Recursive Least Squares) algorithm and S
An adaptive array algorithm such as MI (Sample Matrix Inversion) algorithm is used.

The RLS algorithm and the SMI algorithm as described above are well known in the field of adaptive array processing, and are described in detail in the above-mentioned Document 1, and therefore their explanations are omitted here.

On the other hand, the transmission signal from the modem section 60 of FIG. 2 is modulated by the transmission signal modulation section 53a, and the multiplier M
The reception weight vector calculated by the reception weight vector calculator 52a is copied to the other input terminal of each of the multipliers MT1 and MT2 by the transmission weight vector 54a, Applied as a transmit weight vector.

However, the value of the transmission weight vector output from the transmission weight vector calculator 54a is changed by the control of the transmission directivity control device 55a. That is, the transmission directivity control device 55a, multiplex information indicating whether multiple connection is performed, diversity terminal information indicating whether or not the connected terminal is a diversity terminal,
The communication section information indicating whether or not the section currently being communicated is the preamble section is received from the control unit 80, and a process for changing the transmission directivity is performed.

More specifically, in the preamble section, the transmission weight vector calculator 54a copies the reception weight vector calculated by the reception weight vector calculator 52a and supplies it to one input terminal of each of the multipliers MT1 and MT2. On the other hand, when a plurality of diversity terminals try to make multiple connections, the transmission weight vector calculator 54a is controlled by the transmission directivity control device 55a to change the transmission directivity in the "preamble section". The multipliers MT1 and M
It is applied to one of the input terminals of T2.

As described above, the two systems of digital transmission signals weighted by the complex multiplication with the transmission weight vector in each of the user A signal processing section 50a and the user B signal processing section 50b are given to the radio sections 21 and 22, respectively. To be

The digital transmission signals given to the radio units 21 and 22 are transmitted via the antennas 11 and 12, respectively.

The signals transmitted through the same antennas 11 and 12 as at the time of reception are weighted by the weight vector targeting a specific terminal as in the case of the received signals, and therefore are transmitted from these antennas. As a general rule, the radio wave signal is transmitted with a transmission directivity targeting this specific terminal.

FIG. 6 shows a case where the DSP of the adaptive array base station 1000 (corresponding to the user signal processing unit 50 and the control unit 80 of FIG. 2) is used to realize the transmission directivity control method of the present invention shown in FIG. It is a flow chart for explaining the operation performed.

Referring to FIG. 6, first, base station 1000 is in a call with user 1 (step S100).

Subsequently, it is determined whether or not multiplex communication is being performed with the user 2 in addition to the user 1 (step S102). If the multiplex communication with the user 2 is not being performed, the transmission directivity control device 55a and the drawing are shown. The transmission weight vector calculator 54a and the transmission weight vector calculator 54b (not shown) perform the transmission weight vector calculator 52a without performing the transmission directivity change control from the transmission directivity control device 55b.
And signals from 52a are copied to continue communication (step S120).

On the other hand, if it is determined in step S102 that the user 2 is performing multiplex communication, then it is determined whether or not the user 2 is a diversity terminal (step S104). If the terminal of the user 2 is not the diversity terminal, the communication state is maintained as it is without performing the transmission directivity control (step S120).

On the other hand, when the terminal of user 2 is a diversity terminal (step S104), it is further determined whether the current communication section is the preamble section of the communication signal with user 2 (step S106). . If it is not in the preamble section, the transmission directivity is not controlled (step S120).

On the other hand, if it is determined in step S106 that it is in the preamble section, the process of shifting the phase of the transmission weight vector in order to destroy the transmission directivity of the radio wave to the user 1 is performed by the transmission directivity control device 55a.
Is performed (step S108).

Then, it is determined whether or not the preamble section has ended (step S110), and a standby state is set until the preamble section ends. If it is determined that the preamble section has ended, the process returns to normal transmission directivity control that does not perform control to change the transmission directivity (step S120).

FIG. 7 is a flow chart for explaining a process performed to determine whether or not the terminal of the user 2 is the diversity terminal in step S104 among the processes described in FIG.

In the terminal reception of the user 2, it is judged whether or not the downlink error exceeds a certain amount and there is a request from the terminal side to change the communication channel (step S).
200). Such a request is a "terminal activation interference avoidance request"
Call.

If there is such a terminal activation interference avoidance request, then it is judged whether or not an error exists for uplink reception (step S202), and if an error also exists for an uplink signal. Determines that the terminal is a normal terminal (step S210).

On the other hand, if it is determined in step S202 that there is no upstream error, then it is determined whether or not the upstream reception power is sufficient (step S204).

When it is determined in step S204 that the uplink received power is not sufficient, it is determined that the target terminal is a normal terminal (step S210).

On the other hand, when it is determined in step S204 that the uplink received power is sufficient, it is determined that the target terminal is a diversity terminal, and the ID of such a terminal (hereinafter referred to as PSID) is It is stored in the wireless base station or the host controller connected via the public telephone line 90 (step S220).

That is, in the case of spatial multiple connection,
When the downlink communication performance is deteriorated although the uplink communication performance is good, it is determined that the terminal is a diversity terminal.

By performing the above-described processing as background processing, it is determined whether or not the terminal in communication is a diversity terminal. As a result, in the flow shown in FIG. 6, it is possible to determine in step S104 whether the terminal in the multiplex communication is a diversity terminal.

As described above, it is possible to indirectly determine the type of the terminal by comparing the deterioration of the upstream and downstream signals. However, the control of the transmission power according to the present invention is such a terminal type. The determination method is not limited. For example, the terminal type may be explicitly determined by exchanging some information (flag) that specifies the terminal type.

The embodiments disclosed this time are to be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description but by the claims, and is intended to include meanings equivalent to the claims and all modifications within the scope.

[0104]

As described above, according to the present invention, the diversity power is controlled by shifting the transmission directivity of another user in the preamble section of the target terminal with respect to the transmission power for the diversity terminal. It is possible to increase the possibility that the antenna used at the time of transmission of the terminal is also selected as the receiving antenna, thereby preventing deterioration of the reception performance in the diversity terminal. Furthermore, it enables a plurality of diversity terminals to maintain a spatial multiplex connection to the adaptive array base station.

[Brief description of drawings]

FIG. 1 is a conceptual diagram schematically showing the principle of transmission power and its transmission directivity control according to the present invention.

FIG. 2 is a schematic block diagram showing the configuration of an adaptive array base station 1000 according to the embodiment of the present invention.

FIG. 3 is a conceptual diagram for explaining a configuration of a signal transmitted / received between adaptive array base station 1000 and a terminal.

FIG. 4 is a conceptual diagram for explaining the configuration of the transmission / reception signal shown in FIG. 3 in more detail.

5 is a functional block diagram showing a configuration of a user signal processing section 50 shown in FIG.

FIG. 6 is a flowchart illustrating an operation performed by adaptive array base station 1000.

FIG. 7 is a flowchart illustrating a process performed to determine whether or not the terminal is a diversity terminal.

FIG. 8 shows two diversity terminals U1 and U2
It is a figure which shows typically the state which has been spatially multiplex-connected by the adaptive array process.

[Explanation of symbols]

1 base station, 1a array antenna, U1, U2 diversity terminal, 2a whip antenna, 2b chip antenna, 3a antenna, 11, 12 antenna, 2
1, 22 radio unit, 50 user signal processing unit, 50a
User A signal processing unit, 50b User B signal processing unit, 5
1a demodulation and error determination section, 52a reception weight vector calculator, 53a transmission signal modulation section, 54a transmission weight vector calculator, 55a transmission directivity control device, 60 modem section, 70 baseband processing and T
DMA / TDD processing unit, 80 control unit, 90 public line network, 110 switch, 111 transmitting unit, 112 receiving unit, 113 D / A converter, 114 A / D converter, 1
000 Adaptive array base station, MR1, MR2
MT1, MT2 multiplier, AD1 adder.

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 5K059 CC01 CC04 DD31                 5K067 AA01 BB02 CC24 EE02 EE10                       KK02 KK03

Claims (9)

[Claims] 1. A radio base station in a mobile communication system, wherein the mobile communication system includes a plurality of diversity terminal devices for performing diversity reception capable of spatial multiplex connection to the radio base station, An apparatus is a plurality of antennas, an adaptive array control unit for transmitting a radio wave having a transmission directivity to a desired terminal by an adaptive array processing for the plurality of antennas, and a terminal apparatus connected to the radio base apparatus. A terminal type determining unit that determines whether or not the terminal unit is a diversity terminal device, and a transmission directivity control unit that changes the transmission directivity for the diversity terminal device only for a predetermined period according to the determination result by the terminal type determining unit. A radio base device provided. 2. A signal transmitted / received between the radio base apparatus and the diversity terminal apparatus is composed of a plurality of slots, and each of the slots includes a preamble section composed of a known signal sequence and data to be communicated. Including a data section including, the transmission directivity control means detects that the transmission signal to and from the diversity terminal device is the preamble section, and changes the transmission directivity only in the preamble section, The radio base unit according to Item 1. 3. The terminal type determination device, means for evaluating downlink signal reception performance in a terminal device connected to the radio base device and quality of an uplink signal from the terminal device, and reception of the downlink signal. The radio base station apparatus according to claim 1 or 2, further comprising: a unit that determines that the terminal apparatus is a diversity terminal apparatus when the terminal apparatus is evaluated to have low performance and good quality of the upstream signal. 4. A transmission directivity control method for an adaptive array radio base apparatus, which transmits a radio wave having a transmission directivity to a desired terminal by adaptive array processing for a plurality of antennas in a mobile communication system, comprising: The body communication system includes a plurality of diversity terminal devices that perform diversity reception capable of spatial multiplex connection to the wireless base device, and the transmission directivity control method, the terminal device connected to the wireless base device is a diversity terminal. A transmission directivity control method comprising: a step of determining whether or not the device is a device; and a step of changing the transmission directivity for the diversity terminal device for a predetermined period according to the determination result. 5. A signal transmitted / received between the radio base apparatus and the diversity terminal apparatus is composed of a plurality of slots, and each slot includes a preamble section composed of a known signal sequence and data to be communicated. Including the data section including, the step of changing the transmission directivity detects that the transmission signal to and from the diversity terminal device is the preamble section, and changes the transmission directivity only in the preamble section. The transmission directivity control method according to claim 4, comprising a step. 6. The determining step includes a step of evaluating downlink signal reception performance in a terminal device connected to the radio base apparatus and a quality of an uplink signal from the terminal device, and the downlink signal reception performance. Is low and the quality of the upstream signal is evaluated to be good, the terminal device is determined to be a diversity terminal device.
Alternatively, the transmission directivity control method according to item 5. 7. A transmission directivity control program for an adaptive array radio base apparatus for transmitting a radio wave having a transmission directivity to a desired terminal by adaptive array processing for a plurality of antennas in a mobile communication system, The mobile communication system includes a plurality of diversity terminal devices that perform diversity reception capable of spatial multiplex connection to the wireless base device, and the transmission directivity control program is connected to a computer to the wireless base device. A transmission directivity control program for executing a step of determining whether or not the terminal device is a diversity terminal device, and a step of changing the transmission directivity for the diversity terminal device for a predetermined period according to the determination result. 8. A signal transmitted / received between the radio base apparatus and the diversity terminal apparatus includes a plurality of slots, and each slot includes a preamble section including a known signal sequence and data to be communicated. Including a data section including, the step of changing the transmission directivity detects that the transmission signal with the diversity terminal device is the preamble section, and changes the transmission directivity only in the preamble section. The transmission directivity control program according to claim 7, comprising a step. 9. The determining step includes a step of evaluating downlink signal reception performance in a terminal device connected to the radio base apparatus and a quality of an uplink signal from the terminal device, and the downlink signal reception performance. Is low and the quality of the upstream signal is evaluated to be good, the terminal device is determined to be a diversity terminal device.
Alternatively, the transmission directivity control program according to item 8.