JP2000286777A - Radio base station - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a radio base station that accepts a new call from only a mobile station more ensuring path multiple access or informs the mobile station about a new incoming call. SOLUTION: A signal processing section 50 calculates a 1st parameter group for generating a directivity pattern directing a mobile station under communication and further calculates a 2nd parameter group for generating a directivity pattern where a mobile station under communication is expressed in a null point. A plurality of radio sections use the 1st parameter group to generate a directivity pattern in a communication channel and use the 2nd parameter group to generate a directivity pattern in a control channel.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a plurality of radio units having a transmitting unit, a receiving unit, and an antenna, controls connection with a mobile station via a control channel, and controls the mobile station via a communication channel. The present invention relates to an adaptive array type radio base station that communicates with a base station.

[0002]

2. Description of the Related Art In recent years, an adaptive array system or a path division multiple access (PDMA) has been developed for the purpose of effectively utilizing frequencies and improving communication quality in digital wireless communication equipment.
(Ion Multiple Access) method is drawing attention. The adaptive array method includes a plurality of pairs of antennas and wireless transmission / reception modules, adjusts the gain (amplitude) and phase of each circuit during transmission / reception, generates directivity patterns for transmission and reception, and uses a specific direction. This is a method that allows radio waves to reach only people.

The PDMA system is a system in which signals for a plurality of mobile stations are multiplexed on one radio frequency to simultaneously communicate by forming different directivity patterns for the plurality of mobile stations by an adaptive array system. . Regarding the path division multiple access, refer to “Path division multiple access (PDMA) mobile communication method (IEICE RS98-84 (1994-0)
1))).

By the way, like a base station of a radio telephone,
In the case where path multiplex multiple access is applied to a wireless base station that uses frequencies differently, such as a control channel for controlling transmission / reception and a communication channel for performing communication (communication), the following is performed. That is, the radio base station multiplexes a plurality of mobile stations on the same frequency in the communication channel by path multiplexing multiple access, while allowing the control channel to make and receive calls from anywhere within the service area of the radio base station. Transmit and receive control signals without directivity.

[0005]

By the way, when path multiplex multiple access is applied to a base station of a wireless telephone, the same communication channel is used for mobile stations near a mobile station that is already communicating. There is a problem in that the transmission is accepted or the incoming call is notified, although the path multiplexing can no longer be performed. As a result, there may be a case where the mobile station cannot perform a call by the path multiplex access even though the mobile station can perform a call operation or a call reception at the base station.

[0006] This is because, when a new mobile station makes and receives a call through a control channel in the vicinity of a mobile station already communicating on a certain communication channel, the new mobile station is connected to the same communication channel by path multiplexing. This is because it is no longer possible to discriminate between the communication signals of both mobile stations existing in the vicinity even if an attempt is made to perform multiplexing. The present invention has been made in view of the above problems, and has as its object to provide a radio base station that accepts a new call or notifies a new call only to a mobile station that can more reliably perform path multiplex access.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a radio base station according to the present invention has a plurality of radio units having a transmission unit, a reception unit, and an antenna, and communicates with a mobile station via a control channel. An adaptive array type radio base station that performs connection control and communicates with a mobile station via a communication channel,
First for forming a directional pattern for pointing to a mobile station in communication
First calculating means for calculating a parameter group; second calculating means for calculating a second parameter group for forming a directional pattern with a mobile station in communication at a null point (a point where radio waves do not reach or hardly reach); Control of controlling each transmitting unit to form a directional pattern using a first parameter group in a communication channel, and controlling each transmitting unit to form a directional pattern using a second parameter group in a control channel Means.

Here, the first calculating means calculates a first parameter group from the received signal of the mobile station in communication, and the second calculating means calculates the first parameter group with the received signal of the mobile station in communication. , A non-matching dummy signal may be generated, and the second parameter group may be calculated from the generated dummy signal.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS <Schematic Configuration of Radio Base Station> A radio base station in this embodiment is a base station in mobile communication such as a digital mobile phone, and controls connection with a mobile station via a control channel. This is an adaptive array type radio base station that performs multiple access by path multiplexing and time division multiplexing with a mobile station via a communication channel.

FIG. 1 is a block diagram showing a configuration of a main part of a radio base station according to an embodiment of the present invention. The radio base station includes radio units 10, 20, 30, 40, an antenna 1
7, 27, 37, 47, reception adjustment units 18, 28, 38,
48, a transmission adjustment unit 19, 29, 39, 49, a signal processing unit 50, a baseband unit 51, a memory 52, and a CPU 53.

The radio unit 10 includes a modulator 11, a transmission circuit 1,
2. a modulator 11 which is composed of a switch 13 and modulates a baseband signal (symbol data) input from the baseband unit 51 via the signal processing unit 50 to an intermediate frequency signal (hereinafter abbreviated as an IF signal); A transmission circuit 12 for converting an IF signal from the modulator 11 into a high-frequency signal (hereinafter abbreviated as an RF signal) and amplifying the signal to a transmission output level;
It has a switch 13 for switching between transmission and reception of an antenna, a receiving circuit 15 for converting a received signal into an IF signal, and a demodulator 16 for demodulating the IF signal from the receiving circuit 15 into a baseband signal (symbol data). Where modulator 1
1. The type of modulation and demodulation in the demodulator 16 is not limited as long as it is digital modulation.
SK and the like. In the present embodiment, the baseband signal demodulated by the demodulator 16 is time-series data represented by in-phase component (hereinafter referred to as I component) data and quadrature component (hereinafter referred to as Q component) data for each symbol. Shall be.

[0012] The reception adjustment unit 18 converts the amplitude and phase of the reception baseband signal input from the demodulator 16 to generate a directivity pattern as an adaptive array.
The adjustment is performed according to an instruction from the signal processing unit 50. More specifically, since the baseband signal obtained from demodulator 16 is represented by I component data and Q component data for each symbol,
The reception adjustment unit 18 adjusts the amplitude and phase of the symbol data by weighting each of the I data and the Q data. FIG. 2 is an explanatory diagram showing the contents of adjustment of symbol data by weighting. The figure shows symbol data demodulated by the demodulator 16 on the IQ coordinate plane and symbol data by weighting. I1 and Q1 are demodulator 1
6 shows the symbol data obtained from No. 6. Reception adjustment unit 18
WI1 and WQ1 indicate weighted symbol data. As shown in FIG.
The weight and phase of the symbol data are adjusted by individually weighting the component data. The weighting factor for individually weighting the I component data and the Q component data is determined by the transmission adjustment unit 19 instructed by the signal processing unit 50 to generate a directivity pattern as an adaptive array.
The amplitude and phase of the transmission baseband signal input from the signal processing unit 50 are adjusted. This adjustment is performed in the same manner as in FIG.

The radio units 20, 30, and 40 have the same configuration as the radio unit 10, and a description thereof will be omitted. The signal processing unit 50 is mainly configured by a programmable digital signal processor, and realizes the following functions by executing a program. That is, the signal processing unit 50
A parameter group (weighting coefficient for I component and Q component for each radio system) for realizing a plurality of directivity patterns for PDMA together with transmission / reception control of 〜40 to ４０40, and a reception adjustment unit 18 and a transmission adjustment unit 19 is output.

At this time, the signal processing unit 50 calculates a parameter group for forming a directivity pattern not only in the communication channel but also in the control channel. That is, the signal processing unit 50 calculates a parameter group for forming a directivity pattern pointing to each mobile station in the communication channel, and sets the mobile station in communication on the control channel to a null point (a radio wave does not reach or hardly reaches). Then, a parameter group for forming a directional pattern to be set as (point) is calculated.

FIG. 3 is an explanatory diagram of the directivity pattern formed by the parameter group by the signal processing unit 50. In the figure, PS1 to PS3 indicate mobile stations. 31, 32, and 33 shown by solid lines indicate mobile stations PS1, PS2, and P, respectively.
5 shows a directivity pattern in a communication channel directed to S3. 34 indicated by a broken line indicates mobile stations PS1, PS
2, a directivity pattern in a control channel having PS3 as a null point.

The baseband unit 51 has an interface unit for connecting to a network (public network or private network) not shown in the figure, and connects and time-division multiplexes baseband signals between the signal processing unit 50 and the telephone network. Perform processing. FIG. 4 is an explanatory diagram of a TDMA / TDD frame for performing time division multiplexing.
Here, the so-called PHS telephone system TDMA / T
3 shows a DD frame. In the figure, T0 to T3
Is a transmission time slot, and R0 to R3 are reception time slots. The control channel (CCH in the figure) is constituted by a pair (T0, R0) of a transmission time slot and a reception time slot. Communication channels TCH1, TCH
2, TCH3 is (T1, R1), (T2, R2),
Each is constituted by a pair of (T3, R3). The communication channels TCH1, TCH2, and TCH3 are distinguished by time division. In each communication channel, a plurality of communication channels are further formed by path multiplexing. Further, the carrier frequency fc of the control channel is fixedly determined. As the carrier frequency of the communication channel, an unused carrier frequency is selected. The carrier frequencies of the three communication channels may be the same or different.

The memory 52 stores a program for the CPU 53, a program for the signal processing unit 50, a management table for assigning mobile stations to communication channels, and the like. CP
U53 controls the entire radio base station according to the program in the memory 52, and particularly, when receiving a call from the mobile station via the control channel and receiving a call from the network, A communication channel is allocated, and the allocation status is stored in an allocation management table of the memory 52. FIG. 5 shows an example of the assignment management table. In the allocation management table of FIG. 7, the horizontal direction indicates the communication channel by the time division shown in FIG. 4, and the vertical direction indicates the multiplexing by the path division. In the columns, PS1 to PS3 and the like indicate assigned mobile stations. The figure shows a case where PS1 to PS3 are time-division multiplexed, and there is no mobile station that has been path-multiplexed yet.

The directivity patterns 31 to 33 for PS1 to PS3 shown in FIG. 3 correspond to the case of FIG. In this case, since three mobile stations are time-division multiplexed on TCH1 to TCH3, these mobile stations may be present at close positions. When a fourth mobile station is further connected in this state, since the directivity pattern 34 is given to the control channel as shown in FIG. 3, the mobile station is in a different direction from the three mobile stations that are already communicating. Since the call is transmitted to and received from the fourth mobile station, the reliability of the path multiplex access can be increased.

Even if the directivity patterns 31 to 33 for PS1 to PS3 shown in FIG. 3 are path multiplexed multiple access, similarly, the reliability of the path multiplex multiple access to the fourth mobile station is increased. Can be. <Reception Adjustment Unit> FIG. 6 is a block diagram showing the reception adjustment unit and the signal processing unit 50 of the radio base station shown in FIG. 1 in more detail.

Since the reception adjustment units 18, 28, 38 and 48 have the same configuration, the reception adjustment unit 18 will be described as a representative. The reception adjustment unit 18 includes an I buffer 101, a Q buffer 102, and multipliers 103 and 104. The I buffer 101 holds the I component data obtained from the demodulator 16 while sequentially updating the I component data. This I component data is represented as I1 (t). Here, 1 of I1 is 1 of the first wireless system, and t means the timing of a symbol. Here, the symbol timing indicates symbol timings t0, t1, t2,. During one symbol period, the radio base station uses PHS (Perso
When it is operated as a base station of a nal handyphone system), it takes about 5 microseconds. The I buffer 101 outputs I component data I1 (t) of the latest symbol, and is read from the signal processing unit 50 as needed. It is sufficient that the number of data to be held is at least one symbol.

Like the I buffer 101, the Q buffer 102 holds the Q component data of the latest four symbols obtained from the demodulator 16. The Q component data is represented as Q1 (t). The multiplier 103 weights the I-component data, that is, multiplies the I-component data I1 (t) input from the demodulator 16 by a weight coefficient WI1 (t) provided from the signal processing unit 50.

The multiplier 104 weights the Q component data, that is, the Q component data Q 1 input from the demodulator 16.
(t) is multiplied by a weight coefficient WQ1 (t) given from the signal processing unit 50. The same applies to the reception adjustment units 28, 38, and 48. The symbol data in these are represented as I2 (t), Q2 (t), I3 (t), Q3 (t), I4 (t) and Q4 (t) in the same manner as described above.

In the communication channel, the signal processing unit 50 includes, for each mobile station in communication, a group of parameters for forming a directivity pattern directed to the mobile station (the weight coefficients WI1 (t), WQ1 (t), I2
(t), WQ2 (t), WI3 (t), WQ3 (t), WI4 (t), WQ4 (t))
In the control channel, a parameter group (similar to the above-mentioned weight coefficient) for forming a directivity pattern having a mobile station in communication as a null point is calculated. Here, the calculation of the parameter group is
It is desirable to perform this for each symbol. However, if the arithmetic processing capacity is not sufficient, a representative symbol may be sampled from a plurality of symbols, and the weight coefficient may be calculated only for the representative symbol. In this case, for symbols other than the representative symbol, the weight coefficient of the representative symbol may be used.

The specific arithmetic processing of the signal processing unit 50 will be described below. <Operations of the Signal Processing Unit 50> FIG.
5 is a flowchart showing the processing contents of FIG. In the figure, steps 701 to 703 show processing in the reception time slot R0 of the control channel CCH shown in FIG. 4, and steps 704 to 711 show the communication channels TCH1 to TCH1.
The processing in the reception time slots R1 to R3 of TCH3 is shown. Step 712 shows processing in the transmission time slot T0 of the control channel CCH, and step 713 shows processing in the transmission time slot T1 to T3 of the communication channels TCH1 to TCH3.

In FIG. 7, a signal processing unit 50 forms a directional pattern in which a mobile station during a call is a null point in a reception time slot of a control channel CCH based on a reception signal in a reception time slot of a preceding speech channel. A parameter group (weight coefficient) is calculated (step 701). This calculation method will be described later for convenience of explanation. Further, the signal processing unit 50 combines the received signal of the control channel using the weight coefficient (step 70).
2) The calculated weighting factor is stored in the memory 52 so that it can be used at the time of transmission. The combination of the received signals of the control channel makes it possible to discriminate control signals from mobile stations within the area of the control channel (as indicated by the dashed line in FIG. 3).

Next, the signal processing unit 50 performs a mobile operation for each reception time slot of the communication channel (step 704: loop 1) and for each mobile station communicating in the reception time slot (step 705: loop 2). A parameter group (weight coefficient) for forming a directivity pattern toward a station is calculated. At this time, the calculation of the weight coefficient for one mobile station is performed as follows. That is, the signal processing unit 50
Is the I of all radio units at the representative symbol timing t.
Component data and Q component data (I1 (t) to I4 (t), Q1 (t) to Q4
(t)) is read out from all the I and Q buffers (step 706), a weighting factor for the representative symbol is calculated based on the I component data and the Q component data (step 707), and the weighting factor is used by using the weighting factor. A composite signal of the current symbol t for the user a is calculated using all the multipliers shown in FIG. 6 (step 708). In this calculation, the combined signals YIa (t) and YQ for one mobile station
a (t) is obtained by the following equation. YIa (t) = ΣWIai (t) * Ii (t), YQa (t) = ΣWQai (t) * Qi (t) where i is 1 to 4. This combined signal represents a received symbol at the symbol timing t received by the directivity pattern for the mobile station a. That is, the received symbols from which the received signals of other users have been removed are shown.

Further, the signal processing unit 50 calculates the calculation result (WI
a1 (t) to WIa4 (t), WQa1 (t) to WQa4 (t)) are stored in the memory 52 for use in the next transmission time slot (step 73), and the (representative) received symbol data is combined. Is stored in the memory 52. . The above-described calculation of the weighting factor is performed for each mobile station that has been path-multiplexed in one reception slot (step 710: loop 2). When the calculation of the weighting coefficients and the calculation of the combined signal are completed in each of the reception time slots of TCH1 to TCH3 (step 711: loop 1), the signal processing unit 50 stores the control signal in the memory 52 in the transmission time slot of the control channel. The weight coefficient of the control channel is output to the transmission adjustment units 19, 29, 39, and 49 in accordance with the symbol timing (step 712). As a result, in the control channel, it is possible to form a directivity pattern having a mobile station in communication as a null point.

Further, in the transmission time slot of the communication channel, the signal processing section 50 outputs the weight coefficient of the control channel stored in the memory 52 to the transmission adjusting sections 19, 29, 39, 49 in accordance with the symbol timing (step). 712). As a result, in the communication channel, it is possible to form a directivity pattern directed to a mobile station that is communicating. <Detailed Flow of Weight Factor Calculation Processing> FIG. 8 is a flowchart showing details of the symbol weight coefficient calculation processing in step 707 of FIG.

The processing shown in FIG. 3 applies a known technique relating to an adaptive array using a Kalman filter.
"Study of Adaptive Antenna Using Kalman Filter" (IEICE B-II Vol.J75-B-II No.11
pp 835-843, November 1992), and will be briefly described here. If the signal processing unit 50 has not been initialized, the signal processing unit 50 performs initial settings (steps 81 and 82). In this initial setting, an initial value P (0) of the estimated error variance matrix of the Kalman filter and an initial value W (0) of the weight coefficient matrix are set. In this embodiment, the initial value P (0) = C * I (C is a constant, I is a 4 × 4 unit matrix), and the initial value W (0) is a 4 × 1 column vector shown in FIG. In this case, the weight coefficient matrix W (t) is represented as a 4 × 1 column vector shown in FIG.

Next, the signal processing unit 50 receives the input signal
The I component data and the Q component data of the symbol timing t obtained from the I buffer and the Q buffer are set (step 83), and the reference signal d (t) is set (step 84). Here, the reference signal d (t) is an estimated waveform of a received signal to be obtained from a specific user. The signal processing unit 50 sets the waveform as the estimated waveform if the received signal at the symbol timing t is known data, for example, if the preamble portion of the received data or the user id is used, and if the received signal is unknown data, Tentatively determines the received data of the received symbol and sets its waveform. Here, the received signal Y (t) based on the tentative determination is obtained by multiplying each of the I component data and the Q component data at the symbol timing t by a past weight coefficient and combining them.

Next, the signal processing section 50 calculates the Kalman gain, calculates the pre-estimation error, updates the weighting coefficient, and updates the correlation matrix as shown in FIG.
I do. Steps 85 to 88 are performed by a recursive least square method (RLS) in the Kalman filter.
e) It is a well-known technique using an algorithm), and will not be described here.

In this way, the weight coefficient of the symbol is calculated. <Process for Calculating Weight Factor for Control Channel> FIG.
7 is a flowchart showing the details of step 701, that is, the calculation processing of the weight coefficient for the control channel. First, the signal processing unit 50 determines whether or not there is an empty time slot with reference to the assignment management table shown in FIG. 5 (step 91). If there is an empty time slot, a new mobile station can be further connected by time division multiplexing. Therefore, no directivity pattern is formed. If there is no empty time slot, the new mobile station is path multiplexed. Therefore, the weight coefficient for forming the directivity pattern is calculated as follows.

The signal processing unit 50 generates dummy data from the (representative) received symbol data stored in the memory 52 in the reception time slot of the communication channel (step 92). Here, the dummy data refers to virtual data that does not match any of the received symbol data of a plurality of mobile stations in communication. For example, the signal processing unit 50
Is the received symbol data (Ii
Dummy data (DIi (t), DQi (t)) is created by modifying part or all of (t), Qi (t), and i is a value from 1 to 4. The dummy data may be any value as long as the value does not match the received symbol data. However, data having no correlation may be created, or a random value may be generated and set to a value that does not match.

Next, the signal processing unit 50 performs a weight coefficient calculation process from the generated dummy data (step 9).
3). This processing is the same as the weight coefficient calculation processing shown in FIG. However, the difference is that in reading the input data in FIG. 8, the above-described dummy data is read. Further, the signal processing unit 50 stores the calculated weight coefficient in the memory 52 (step 94),
A received signal for each wireless unit is synthesized using the calculated weight coefficient (step 95).

As described above, in the control channel, the weighting factor for forming the directivity pattern is calculated using the dummy data that does not match the received symbol data of the mobile station that is communicating, so that the communication channel that is communicating in the control channel is used. It is possible to obtain a weighting coefficient for forming a directivity pattern having a mobile station as a null point. As described above, the radio base station according to the present embodiment forms a directivity pattern directed to a mobile station on a communication channel, and forms a directivity pattern having a null point on the mobile station on a control channel. Thus, a new mobile station in the vicinity of the mobile station that is already communicating,
The control signal of the control channel from this wireless base station will not arrive. Therefore, for the new mobile station,
Since the radio base station does not accept a call or notify an incoming call, it is necessary to eliminate the need to perform call control on the control channel even though the control channel cannot actually shift to communication. Can be. In this case, the new mobile station receives the control signal of another radio base station, so that it is possible to transmit and receive more reliably.

In the above embodiment, an example in which the time division multiplex access and the path multiplex access coexist has been described. However, a radio base station which performs only the path multiplex access may be used. Further, in the above embodiment, as shown in FIG. 5, a communication channel is assigned with priority given to time division multiplexing over path multiplexing, and when there is no free time slot due to time division multiplexing, the directivity pattern of the control channel is formed However, it may be preferentially assigned from path multiplexing.

Further, when there is an empty time slot by time division multiplexing, it is not necessary to form a directivity pattern in a communication channel.

[0038]

The wireless base station of the present invention has a plurality of wireless units having a transmitting unit, a receiving unit, and an antenna, controls connection with a mobile station via a control channel, and establishes a connection via a communication channel. An adaptive array type radio base station that communicates with a mobile station, the first calculating means for calculating a first parameter group for forming a directivity pattern pointing to the mobile station that is communicating, A second calculating means for calculating a second parameter group for forming a directivity pattern to be a point; and controlling each transmitting unit to form a directivity pattern using the first parameter group in a communication channel; And control means for controlling each transmitting unit so as to form a directional pattern using the second parameter group.

According to this configuration, the radio base station forms a directivity pattern directed to the mobile station on the communication channel, and forms a directivity pattern having the mobile station as a null point on the control channel. As a result, the control signal of the control channel from the wireless base station does not reach a new mobile station near the mobile station that is already communicating. Therefore,
Since this radio base station does not accept the call or notify the incoming call to the new mobile station, the incoming / outgoing call on the control channel despite the fact that it is not possible to actually shift to communication on the control channel The problem of performing control can be eliminated. Further, the new mobile station receives the control signal of another radio base station, so that it is possible to transmit and receive more reliably.

Further, the first calculating means calculates a first parameter group from the received signal of the communicating mobile station, and the second calculating means calculates the first parameter group from the received signal of the communicating mobile station. A configuration may be such that a dummy signal that does not match is generated, and the second parameter group is calculated from the generated dummy signal. According to this configuration, by generating the dummy signal, the calculation processing of the first parameter group and the calculation processing of the second parameter group can be shared.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a main part of a wireless base station according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing adjustment contents of symbol data by weighting.

FIG. 3 is an explanatory diagram of directivity patterns of a communication channel and a control channel.

FIG. 4 is an explanatory diagram of a TDMA / TDD frame for performing time division multiplexing.

FIG. 5 shows an example of an assignment management table based on time division multiplexing and path multiplexing.

FIG. 6 is a block diagram showing each reception adjustment unit and signal processing unit 50 in more detail.

FIG. 7 is a flowchart showing processing contents of a signal processing unit 50;

FIG. 8 is a flowchart showing details of symbol weighting coefficient calculation processing.

FIG. 9 is a flowchart showing the contents of a process of calculating a weight coefficient for a control channel.

[Explanation of symbols]

 10 to 40 Radio section 11 Modulator 12 Transmission circuit 13 Switch 15 Receiving circuit 16 Demodulator 17 Antenna 18 Reception adjustment section 19 Transmission adjustment section 20 Radio section 28 Reception adjustment section 31-34 Directivity pattern 50 Signal processing section 51 Baseband section 52 Memory 53 CPU 101 I buffer 102 Q buffer 103 Multiplier 104 Multiplier

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5J021 AA05 AA09 AA11 DB02 DB03 EA04 FA06 FA13 FA17 FA20 FA26 FA30 FA31 FA32 GA02 GA06 GA08 HA05 HA10 5K022 FF00 5K028 AA15 BB06 CC02 CC05 DD01 DD02 HH02 LL02 MM12 RR02 BB02 EE22 EE41 GG01 GG11 JJ12 JJ13 KK02 KK03

Claims (2)

[Claims] 1. An adaptive array type having a plurality of wireless units having a transmitting unit, a receiving unit, and an antenna, performing connection control with a mobile station via a control channel, and communicating with the mobile station via a communication channel. A first base station for forming a directional pattern for pointing to a mobile station in communication.
A first calculating means for calculating a parameter group; a second calculating means for calculating a second parameter group for forming a directional pattern having a mobile station in communication as a null point; And control means for controlling each transmission unit to form a directivity pattern using a second parameter group in a control channel. base station. 2. The first calculating means calculates a first parameter group from a received signal from the communicating mobile station, and the second calculating means calculates a first parameter group from the received signal from the communicating mobile station. The radio base station according to claim 1, wherein a dummy signal that does not match is generated, and a second parameter group is calculated from the generated dummy signal.