JP3452447B2 - CDMA system and transmission power control device therefor - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system using a CDMA (code division multiple access) system in land mobile communication, and more particularly to a transmission power control technique required to increase channel capacity.

[0002]

2. Description of the Related Art A CDMA system is a multiple access system using spread spectrum modulation and is a system for transmitting space, frequency and time in a mutually overlapping manner. The spread spectrum method is a method in which the information to be transmitted is subjected to normal modulation (information modulation), and then further modulated with a pseudo-random code (spread modulation) for transmission.
Spread modulation of 0 to several hundred times is performed.

In the CDMA system in mobile communication, two-way communication is performed between a base station and a plurality of mobile stations. However, if there is a large difference in the received power from the mobile station, the received power will increase. A small mobile station may be incapable of communication due to a large interference from a mobile station having a large received power. This is called the near-far problem, and transmission power control is performed to overcome this problem.

The transmission power control is to perform control so that reception of transmission power from each mobile station in the base station is equalized. Then, if the received power from the base station in the mobile station is high, the transmission power of the mobile station is set to be small if it is small (this is called open loop power control), and the received signal from each mobile station is set in the base station. By measuring it, comparing it with a reference value, generating a transmission power control command, and feeding it back to the mobile station (this is called closed loop power control), the received power from each mobile station at the base station is constant. The control is performed so that For a conventional transmission power control device, see WO9
1/07037, WO92 / 10028, US90 / 0
6418 and the like.

FIG. 14 shows a configuration of a base station in a conventional transmission power control apparatus. RF signals received from all mobile stations belonging to the cell are supplied to an analog receiver 1403 through an antenna 1402. To be done. In the analog receiver 1403, RF signal amplification, frequency conversion, and IF processing are performed, and broadband SS (spread spectrum) is performed.
Become a signal. This signal is supplied to the mobile station unit N1401 and other mobile station units. The mobile station unit N1401 performs the following processing. Digital data receiver 1404 performs correlation processing and despreading,
User power baseband 1405 as a narrow band digital signal and received power measuring device 14 as a narrow band signal
Output to the user digital baseband 140
In 5, the intended reception and the interface to the public network are performed, and the user information signal is supplied to the TX modulator 1407. The received power measuring device 1406 measures the received signal power level from the mobile station N, generates a power control command, and supplies it to the TX modulator 1407. The TX modulator 1407 performs SS modulation of the user information signal and inserts a power control command. The mobile station unit N1401 outputs the SS modulated signal by the above processing. Then, the adder 1408 synthesizes the SS modulated signal of another mobile station unit and supplies the synthesized SS modulated signal to the adder 1409. The adder 1409 synthesizes the pilot signals generated by the pilot signal generator 1410, frequency-converts and amplifies the synthesized signal (not shown in the figure), and then the antenna 14
It is radiated to each mobile station through 02. The pilot signal is used by the mobile station as a reference for initial acquisition, synchronization holding, and timing of the mobile station.

FIG. 15 shows the configuration of a mobile station in a conventional transmission power control apparatus. A received signal from a base station is supplied to an analog receiver 1502 through an antenna 1501. In the analog receiver 1502, amplification and frequency conversion are performed. One signal is used as an IF signal in the digital data receiver 1503, and the other signal is used as an analog measurement signal obtained by combining the powers of all base stations. It is supplied to the controller 1508. In the digital data receiver 1503, despreading,
Correlation is performed and one signal is provided as voice coded data to the user digital baseband 1504 and the other output is provided to the control processor 1506 with the extracted power control command. User digital baseband 1504 performs decoding and user interface (output to speaker, input from microphone, etc.). The information to be transmitted is encoded here and supplied to the TX modulator 1505 as encoded data. The TX modulator 1505 performs SS modulation, and the transmission power controller 15
It is supplied to 07. The control processor 1506 is provided with a mobile station reference power level. It is either stored in memory or included in the information received at the mobile station. In addition, a power control command is supplied from the digital data receiver 1503. The power control command is a signal transmitted from the base station at several hundreds to several kbps, and 1d according to the polarity of this command.
It is a signal for increasing or decreasing B. For example, if it is 0, it is increased by 1 dB, and if it is 1, it is decreased by 1 dB. The control processor 1506 supplies this signal to the transmission power controller 1507 in a predetermined variable range. Also, by performing a predetermined averaging based on the reference power level,
The level set command is supplied to the transmission power controller 1508. In the transmission power controller 1507, the TX modulator 15
Transmission power control is performed on the SS signal from 05 according to an instruction from the control processor 1506. Then, the transmission power controller 1508 performs transmission power control in accordance with a command from the control processor 1506, and the analog receiver 150
According to the analog measurement signal from 2, the transmission power value is set to be small when the reception power is large, and conversely is set to be large when the reception signal is small. This is frequency-converted, amplified, and radiated toward the base station through the antenna. Conventional transmission power control is performed by operating the base station and mobile station as described above.

Regarding the transmission power during variable rate transmission,
For example, it is described in US Pat. No. 5,103,459, and as shown in FIG. 16, with the full rate as a reference, as the rate becomes half, the electric power becomes 1/2 on average. There is also a method in which continuous transmission is used instead of constant power position randomization transmission as shown in the figure, and the power value is changed. Further, there is also a method in which a plurality of codes are used for transmission at a high bit rate, although the transmission is continuous and the power value is constant.

On the other hand, a CDMA system using a directional antenna is disclosed in, for example, Japanese Patent Application Laid-Open No. 7-87011, and as shown in FIG.
The channel c, which has a small temporal variation, is used as a wideband CDMA signal, and the channel a, which is originally a narrowband signal and whose number varies greatly with time, is used as a narrowband CDMA signal. As shown in FIGS. 18 and 19, the directional antenna is used to reduce the antenna gain in the direction of the interfering station and consequently disconnect the interfering station 1901 from the cell B.

Further, a conventional DBF (digital beam forming) antenna and a CDMA demodulation unit are described in, for example, "Consideration on application of DBF antenna to CDMA mobile communication base station system" by Karasawa, Chiba et al. A.
P94-121 / RCS94-129, Feb. 199
5 is shown. FIG. 20 is a block diagram showing the configuration of the base station antenna receiving unit. The input from the antenna 1301 is amplified by the LNA 1302, and then the local oscillator 1303, the mixers 1305 and 1306, and the phase shifter 1304.
Is converted into a baseband signal by the A / D converter 13
The signals 07 and 1308 are supplied to the DBF unit 1309 as digital signals. The DBF unit 1309 separates each input into directional beam components, and the output is supplied to the correlation calculation units 1310 to 1318 as beam component signals. Then, in the correlation calculation units 1310 to 1318, the correlation is performed by the PN code corresponding to the channels 1 to N of the mobile station. These outputs are used for further processing as the power value of each channel for the antenna beam number.

[0010]

Since the conventional power control apparatus is configured as described above, when performing transmission in which various rates coexist, a certain high bit rate mobile station will operate at a low bit rate. However, there is a problem in that it causes a large interference to the station and, as a result, the power control is performed well, but the channel capacity is reduced. This will be explained in more detail below.

According to the transmission system of FIG. 16, the transmission power value at the full rate is 1 of the transmission power value at the 1/8 rate.
/ 8, and assuming that the spreading gains of both are the same, when transmission power is applied so that the base station reception power becomes constant,
The full-rate transmission is in a state of receiving a lot of interference.
Even if you try to give a difference in gain, if you try to give more spreading gain to a high transmission rate,
Furthermore, a wide band is required.

Therefore, if the high-rate signal is transmitted with a small spreading gain and a large power value, the high-bit rate signal causes a lot of interference with the low-bit rate signal. .

It is also conceivable to transmit a high bit rate one having a very wide band as shown in FIG.
In the A system, even a narrow band type requires a bandwidth of about 1 MHz, so a wide band type is several 100M.
Hz to several GHz, which is difficult to realize in terms of hardware and unacceptable in terms of system (such a wide frequency cannot be assigned). As a result, the system cannot meet the demand for a signal that requires a wide band.

If the mobile station that gives a lot of interference is cut off as shown in FIGS. 18 and 19, the interference of the adjacent cell increases or the mobile station cannot communicate.

Further, the above problem can be solved by using a parallel transmission system in which a plurality of codes are assigned to the transmission of one channel, but since the number of channels decreases, the interference amount has a margin. Nevertheless, it causes another problem that a new mobile station cannot join the system.

Further, since the conventional DBF antenna is configured as described above, there is a problem in that the correlation calculation becomes enormous and it cannot be calculated in real time, or that a large amount of hardware requires high power consumption. .

The present invention has been made to solve the above problems, and is a CDMA system capable of increasing the channel capacity by keeping the received power to interference power density ratio of a high bit rate mobile station and a low bit rate station constant. An object is to provide a transmission power control device for a system.

Further, since it can be allocated to the transmission using the directional antenna, the reception power of the antenna of the high bit rate station can be lowered and the channel capacity can be increased.
The purpose is to provide an MA system.

Another object of the present invention is to provide a DBF antenna which can reduce power consumption by adaptively stopping the operation of the DBF.

[0020]

A transmission power control apparatus according to the present invention includes a base station having a directional antenna and an omnidirectional antenna, and at least one of an omnidirectional antenna and a directional antenna. In a CDMA system that performs two-way communication with two or more mobile stations, the received power by the directional antenna of the base station with respect to the mobile station transmission power,
The control means comprises control means for controlling the reception power of the omnidirectional antenna of the base station to be equal, and the control means compares the reception power of the omnidirectional antenna with a first reference value to receive the directional antenna. A transmission power control apparatus, wherein a power control command is generated by comparing power with a second reference value.

Further, the transmission power control apparatus according to the present invention is characterized in that the directional antenna is a beamforming antenna.

Further, the transmission power control apparatus according to the present invention is characterized in that the first reference value and the second reference value are obtained by the signal power to interference power density ratio of the received signal.

Further, the transmission power control apparatus according to the present invention is characterized in that the base station allocates a directional beam to a mobile station which requests high bit rate transmission.

Further, the transmission power control apparatus according to the present invention is characterized in that, in the case of high bit rate transmission, the transmission gain is smaller than the spreading gain of low bit rate transmission.

Further, the transmission power control apparatus according to the present invention is characterized in that the base station is configured to assign a predetermined spreading gain according to the bit rate assigned to the mobile station.

Further, the transmission power control apparatus according to the present invention is characterized in that the first reference value and the second reference value can be changed in weight for each channel.

The CDMA system according to the present invention includes a base station having a directional antenna and an omnidirectional antenna, and one or more mobile stations having at least one of an omnidirectional antenna and a directional antenna. In a CDMA system that performs two-way communication by means of transmission power control means for controlling the transmission power so that the reception power of the directional antenna of the base station with respect to the transmission power of the mobile station becomes equal to the reception power of the omnidirectional antenna of the base station. The control means is configured to generate the power control command by comparing the received power of the omnidirectional antenna with a first reference value and by comparing the received power of the directional antenna with a second reference value. And

Further, the CDMA system according to the present invention is characterized in that the beam of the directional antenna is overlapped with the zone of the omnidirectional antenna.

Further, the CDMA system according to the present invention is characterized in that the directional antenna is a beamforming antenna.

Further, the CDMA system according to the present invention, when the directional beam is allocated in the base station,
A plurality of mobile stations adjacent to each other are collectively accommodated in a directional beam.

Further, in the CDMA system according to the present invention, when the directional beam is allocated in the base station,
It is characterized in that a plurality of mobile stations having different zones by the omnidirectional antenna are collectively accommodated in a directional beam.

Further, the CDMA system according to the present invention is characterized in that a directional beam is allocated to a mobile station independently of other beams when a beam that can be allocated exists in the base station.

Further, the CDMA system according to the present invention is characterized in that the directional beam allocation to the mobile station is shared with another adjacent mobile station when there is no allocable beam in the base station. .

Further, the CDMA system according to the present invention is characterized in that the mobile station requesting a high bit rate transmits at a low bit rate at the time of initial transmission, and the base station uses a control algorithm using an omnidirectional antenna. And

[0035]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1. Embodiment 1 of the present invention will be described below with reference to the drawings.
1 is a block diagram of a base station showing Embodiment 1 of the present invention. The transceiver 101 using an omnidirectional antenna includes an omnidirectional antenna 103, a transmission / reception separating means 105, and a common RX.
Processing means 107, common TX processing means 109, adder 11
1, a pilot signal generator 113, a channel 1 modulator / demodulator 115, a channel 2 modulator / demodulator 117, ..., A channel M modulator / demodulator 119.

The signal received by the antenna 103 is supplied to the common RX processing means 107 through the transmission / reception separating means 105. The common RX unit 107 is a process commonly performed for all channels, and performs frequency conversion, filtering, AGC, etc. of the received signal. The output of the common RX processing means 107 is supplied to the channel 1 modulator / demodulator 115 to the channel M modulator / demodulator 119. Channel 1 modulator / demodulator 1
At 15, the RX processing means 121 performs channel separation and the like, and one output is connected to the public network through the codec as reproduced data.

The other output is used as a power value to compare means 1.
23 and the common control means 129. Comparison means 1
In 23, the reference value 1 from the common control means 129 is compared with the magnitude of the electric power, and the result is used as the information of one symbol in the TPC.
(Transmission power control) Supply to the command generation means 125.
In the TPC command generation means 125, according to the comparison result,
Generate a TPC command. For example, when the comparison result is larger than the reference value 1, a command of 1 for lowering the power is generated. This command is sent to the TX processing means 127.
Supply to. The information to be transmitted next is supplied from the public network to the TX processing means 127 through the codec. By inserting the TPC command here, the TPC command is transmitted to the mobile station together with the information. The output of the TX processing means 127 is added to the adder 1 together with the signals of other channels.
The common TX processing means 10 is supplied to the common TX processing means 10 and is combined therewith with signals of other channels and is also combined with the pilot signal generated from the pilot signal generator 113.
9 is supplied. The pilot signal is a signal used for initial acquisition, synchronization holding, and timing reference of the mobile station. The common TX processing unit 109 performs common processing for all channels such as frequency conversion, filtering, HPA, and the like. Then, it is radiated from the antenna 103 to the mobile station through the transmission / reception separating means 105. Here, the channel 1 modulator / demodulator 115 to the channel M modulator / demodulator 1
19 has the same configuration except for the code for channel separation. Here, conventionally, respective reference values are determined so as to be suitable for channels 1 to M, and transmission power control is performed.

The modulator / demodulator with a directional antenna operates similarly for channels (M + 1) to N. That is, the transceiver 102 using the directional antenna is
4, transmission / reception separating means 106, common RX processing means 108,
Common TX processing means 114, adder 110, pilot signal generator 112, channel (M + 1) modulator / demodulator 11
6, channel (M + 2) modulator / demodulator 118, ..., Channel N modulator / demodulator 120. Antenna 1
The signal received at 04 is passed through the transmission / reception separation means 106 and supplied to the common RX processing means 108. The common RX unit 108 is a process commonly performed for all channels, and performs frequency conversion, filtering, AGC, etc. of the received signal. The output of the common RX processing means 108 is supplied from the channel 1 modulator / demodulator 116 to the channel M modulator / demodulator 120. In the modem for channel (M + 1) 116, R
Channel separation and the like are performed by the X processing means 122, and one output is connected to the public network through the codec as reproduced data.

The other output is used as a power value to compare means 1.
24 and the common control means 126. Comparison means 1
In 24, the reference value 1 from the common control means 129 is compared with the magnitude of the electric power, and the result is used as the information of 1 symbol in the TPC.
It is supplied to the command generation means 126. The TPC command generating means 126 generates a TPC command according to the comparison result. For example, when the comparison result is larger than the reference value 1, a command of 1 for lowering the power is generated. This command is supplied to the TX processing means 128. The information to be transmitted next is T from the public network through the codec.
It is supplied to the X processing means 128. By inserting the TPC command here, the TPC command is transmitted to the mobile station together with the information. The output of the TX processing means 128 is supplied to the adder 110 together with the signals of the other channels, and is combined there with the signals of the other channels, and
The pilot signal generated from the pilot signal generator 112 is also combined and supplied to the common TX processing means 114. The pilot signal is used for initial acquisition of the mobile station, synchronization holding,
This signal is used as a timing reference. Common T
In the X processing means 114, frequency conversion, filtering,
Common processing is performed in all channels such as HPA. Then, it is radiated from the antenna 104 to the mobile station through the transmission / reception separating means 106. Here, the channel (M + 1) modulator / demodulator 116 to the channel N modulator / demodulator 120 have the same configuration except for the code for channel separation. Here, conventionally, the respective reference values are determined so as to be suitable for the channels M + 1 to N, and the transmission power control is performed.

In the common control means 129, the first reference value for channels 1 to M and the second reference value for channels (M + 1) to N are related by the following relational expression. (First reference value) = (sum of power values from 1 to M) / M (second reference value) = (sum of power values from (M + 1) to N) / ( NM) , The power value of the directional antenna is
Since the power value due to the directional antenna can be reduced by (omnidirectional antenna gain / directional antenna gain), the channel capacity can be increased by controlling the transmission power.
It is preferable that the first reference value and the second reference value are independently given to the comparing means of channels 1 to M and the comparing means of channels (M + 1) to N, respectively. As a result, different power values depending on the transmission rate and high quality services can be supported.

Although only one antenna is shown in FIG. 1, space diversity can be performed by a plurality of antennas.

Next, the common RX processing means 107 will be described in detail. FIG. 2 shows the configuration of the common RX processing means according to the first embodiment of the present invention. The received signal from the transmission / reception separating means 105 is an LNA (low noise amplifier).
Amplified by 201, frequency conversion into an IF signal is performed by mixer 202, and BPF (bandpass filter)
At 203, unnecessary frequency components are removed. And AGC
After having a predetermined level signal by 204, the duplexer 20
The signal is divided into two by 5 and the respective signals are supplied to the mixers 206 and 207. Here, the local oscillator 209, the phase shifter 210, and the quadrature detection by the mixers 206 and 207 are performed, and the respective signals are subjected to LPF (low-pass filter) 208 and 209 to remove unnecessary frequency components and, if necessary, waveform shaping. Done, A / D 210, 21
1 is supplied. Although the common RX process is performed in this way, AFC (automatic frequency control) or the like is also performed as necessary.

A 90 ° demultiplexer may be used instead of the phase shifter 210, and a synthesizer may be used instead of the local oscillator. The common RX processing means 108 also operates in the same manner as above.

Next, the common TX processing means 109 will be described in detail. FIG. 3 shows the common T according to the first embodiment of the present invention.
The X processing means is shown. Each input digital signal is converted into an analog signal by the D / A 301, 302, unnecessary frequency components are removed by the LPFs 303, 304 and waveform shaping is performed if necessary, and the mixer 305,
Is supplied to 306. Here, the IF local oscillator 309
And the phase shifter 310 performs quadrature modulation. The respective mixer outputs are supplied to LPFs 307 and 308, where unnecessary frequency components are removed. The respective LPF outputs are combined by the combiner 311, and the variable voltage amplifier 312 is combined.
Is amplified by. Then, after being converted into an RF frequency by the mixer 313, unnecessary frequencies are removed by the BPF 314, it is amplified by the HPA 315 to a high power. Thereafter, as shown in FIG. 1, the antenna is radiated toward one or more mobile stations through the transmission / reception separating means.

Although the common TX processing is performed as described above, a 90 ° demultiplexer may be used instead of the phase shifter 310, and a synthesizer may be used instead of the local oscillator. The common TX processing means 110 also operates in the same manner as above.

Next, the channel 1 RX processing means 121 will be described in detail. FIG. 4 shows RX processing means for channel 1 according to the first embodiment of the present invention. The two signals converted into digital signals by the common RX processing means 107 are supplied to correlators 401 and 402, respectively. The correlators 401 and 402 are multipliers 403 and 40.
4, integrated discharges 405 and 406, and averaging 407 and 408. The received signal and the channel 1 PN (pseudo noise) sequence are multiplied at appropriate timings by the multipliers 403 and 404, and the result is PN sequence 1 Integral discharge in 4 cycles
05, 406 and average 40 to get the desired quality
7, 408, the correlation is performed, and thus the signal of channel 1 is extracted. After this, the two signals are supplied to the data regenerator 409 and the power calculator 410. The data regenerator 409 performs determination of two signals, parallel / serial conversion, and the like, and this output is connected to the public network through the codec. The power meter 410 calculates the sum of squares of the two signals, and the output is supplied to the comparison means 123 and the common processing means 129 as shown in FIG. 1 for further processing. In this way, RX processing for channel 1 is performed. Further, the channel 2 RX processing means has the same configuration as the channel 1 RX processing means, and the correlator 40
It is only necessary to use the one for channel 2 as the PN sequence of 1,402 inputs. Similarly, the channel M RX processing means has the same configuration as the channel 1 RX processing means, and it is only necessary to use the channel M one for the PN series of the correlators 401 and 402.

Although the correlator structure based on the integral discharge is shown here, a matched filter may be used. Furthermore, although the power measuring device calculates the sum of squares, the square root may be taken. The channel (M + 1) RX processing means to the channel N RX processing means can be similarly configured.

Next, the channel 1 TX processing means 127 will be described in detail. FIG. 5 shows the TX processing means for channel 1 according to the first embodiment of the present invention. Figure 1
As described above, the information from the public network passes through the codec, is input as the information in FIG. 5, and is supplied to one of the switches 501. The other input of the switch 501 is TPC
The command is entered. The switching of the switch depends on the transmission method, but the switching is performed such that the switch is inserted at a position determined for each TPC command rate, or the insertion position is determined and inserted by a randomization algorithm.

When another signal is inserted in the information as described above, the mobile station removes the part from the information or applies an error correction code on the transmitting side and uses a corresponding decoder on the receiving side. It is also possible. Then, the switch output is separated into two by the serial / parallel conversion 502, and each is supplied to the multipliers 503 and 505.

The multipliers 503 and 505 perform multiplication with the PN sequence for channel 1, and the respective outputs are further supplied to multipliers 504 and 506, where the power distribution determined by the system is multiplied as the weight of channel 1. To do. These outputs are used for A / D conversion in the common TX processing means. In this way, the TX processing for channel 1 is performed. The TX processing for channel 2 has the same configuration as the TX processing means for channel 1, and has multipliers 503 and 50.
The 5 input PN sequence for channel 2 is used, and the multiplier 5
It is only necessary to use the channel weights for channel 2 for 04 and 506. Similarly, the TX processing for the channel M has the same configuration as the TX processing means for the channel 1, and the multiplier 50
It is only necessary to use the channel M for the PN sequence of 3,505 inputs and the channel weight for the channel M for the multipliers 504 and 506.

Next, the common processing means will be described in detail. The reception Eb / I0 (bit power to interference power density ratio) of the signal from each mobile station at the base station is calculated as follows.
Eb is the correlation value obtained by the correlation with the code assigned to itself converted into the power dimension, and I0 is the total power of all other stations. However, since it is generally difficult to obtain the total power including the neighboring cells, I0 is often obtained by dividing the total power measurement value using AGC by the bandwidth.

FIG. 6 shows the common processing means 129 according to the first embodiment of the present invention. In the omnidirectional antenna common processing unit 101, the power value input of channel 1 is supplied to the computer 601, and in the computer 601,
Add all the power values from channel 1 to channel M,
The reference power is calculated by dividing it by M. This reference value may be weighted by the transmission rate as well as by the service. This output is averaged by averaging 607 to obtain a reference value 1, which is supplied as an input to the comparing means 123 in FIG. The same calculation is performed for the channels 2 to M, and the reference value M is obtained from the reference value 2. Figure 1
In the description, the reference value 1 to the reference value M are referred to as the first reference value. Although the computers 601 to 607 are shown as being different here, they may be performed by a single computer.

Further, the common processing unit 102 for directional antennas
Then, the power value input of the channel (M + 1) is calculated by the computer 60.
4 and the channel (M +
The reference power is calculated by adding all the power values from 1) to channel N and dividing it by (N−M).
This reference value may be weighted by the transmission rate as well as by the service. This output is averaged by averaging 607 to obtain a reference value (M +
1) is obtained, which is supplied as an input to the comparing means 124 in FIG. The calculation is similarly performed for the channel (M + 2) to the channel N, and the reference value N is obtained from the reference value (M + 2). In the description of FIG. 1, the reference value (M +
From 1) to the reference value N was referred to as a second reference value.

By adopting the above base station configuration,
An increase in channel capacity during high bit rate transmission is constructed. The details will be described below. For example, 1 at the base station
It is assumed that 00 channels can be accommodated, the reference power for low bit rate transmission is P, and high bit rate transmission can be from 2 to 64 times P.

As shown in FIG. 7, when the transmission rate is the basic rate R, one information symbol is multiplied by one period of the PN series, and when the transmission rate is 2R, two information symbols are transmitted.
Multiply one cycle of N series. Similarly, transmission rate 6
In the case of 4R, the information 64 symbols are multiplied by one cycle of the PN sequence. As a result, the spreading gain at the basic rate R is G
Then, in case of 2R, G / 2, ..., and in case of 64R, G
/ 64. Therefore, both mobile stations and base stations perform power weighting according to the transmission rate.

Further, it is assumed that the omnidirectional antenna gain is G and the directional antenna gain is 100G. At this time, when all the mobile stations perform low bit transmission, power of P is received by the base station as shown in FIG. 8A, and 100 channels can be transmitted simultaneously. However, when one mobile station transmits at a rate of 64 times, one station corresponds to 64 stations as shown in FIG. 8B, and 37 channels are simultaneously transmitted.
And it is not possible to assign a rate of 64 times more to the mobile station. Therefore, if the 64 × rate transmission is transmitted by the directional antenna system, the transmission rate of
As in (C), it is possible to transmit with the power of (64/100) P. Therefore, the channel can be increased by allocating the surplus power resource to other subscribers.

Embodiment 2. The second embodiment of the present invention will be described below with reference to the drawings.
When the omnidirectional antenna and the directional antenna are used in the CDMA system, it is possible to use different frequencies, but the same frequency is used here. When an omnidirectional antenna is used, a wireless zone centered on the base station is constructed as shown in FIG. In FIG.
C1 to C7 have the same frequency, but are arranged so that the signs (code phases) are different.

The beam from the directional antenna is shown in FIG.
Like 0, the omnidirectional antenna is formed so as to overlap the zone. As shown in FIG. 10, the directional beam can accommodate not only one mobile station but also a plurality of mobile stations having different zones at the same time.

FIG. 11 shows transmission control until a mobile station requesting a high bit rate is actually assigned to a radio zone using such a directional antenna. First, the mobile station performs initial acquisition with the pilot signal from the base station (step 1106). The pilot signal is a signal that consists of all 0s, although the PN sequence is applied. The pilot receiver and the mobile station receive the channel for broadcasting the system information and synchronize with the system (step 1107). Then, the mobile station starts access to the base station (step 1108). At this time, the mobile station inserts a high bit rate request message in the access information. At this time, access is performed with low power at the basic rate R so as not to interfere with other channels.

The base station receives the high bit rate request message from the mobile station (step 1102), and if the allocation is possible, adjusts the direction of the directional antenna to the mobile station (step 1103) and sends it to the mobile station. A high bit rate permission message is transmitted (step 1104). The power value of the directional antenna system is included in this message.
The mobile station resets the transmission power value from the high bit rate permission message from the base station and performs transmission (step 110).
9). As described above, it is possible to perform high bit rate transmission without causing interference with other stations. When the high bit rate request cannot be assigned, a high bit rate non-permission message is transmitted to the mobile station.

As shown in FIG. 12, this judgment algorithm of the base station judges whether or not there is a directional beam resource (step 1201), and if there is, allocates it (step 1202). Even if it is not included, it is included in the adjacent beam if it can be included in the adjacent beam (step 12).
03, 1204). By operating in this way, a high bit rate station can be accommodated by a directional beam, so that the channel capacity can be increased.

If the adjacent beam cannot be accommodated, the transmission of the directional antenna is abandoned, the high bit rate non-permission message is transmitted to the mobile station, and the judgment criteria as shown in FIG. 12 are followed (steps 1205 to 1205). 1209).

Embodiment 3. The third embodiment of the present invention will be described below with reference to the drawings.
FIG. 13 is a configuration diagram when a DBF antenna according to the third embodiment of the present invention is used. Switching means 1337 and a correlator 1338 are newly added to the configuration according to FIG. 20, and gate signals are added to correlation diagrams 1310 to 1318. Of the shift register 1 to the outputs of the correlators 1310 to 1318
319 to 1327, switches 1328 to 1330, algorithms 1331 to 1333, MRC (maximum ratio combining) 1
334 to 1336 are added.

All the inputs from the correlator 1310 to the correlator 1318 of the DBF 1309 output are supplied to the switching means 1337, where they are switched at a predetermined time interval. This switching is in a beam that changes from moment to moment,
A high level is performed for a long time and a low level is performed for a short time, and the high level is supplied to the correlator 1338. In the correlator 1338, channels 1 to P are correlated with DBF outputs 1 to Q. By comparing this result with a predetermined value, the gate signals gatell to gate
Generate QP. The predetermined value is, for example, a threshold signal for combining the maximum five, and the gate signal is, as a result,
It is used to control the activity or cessation of the correlation values 1310 to 1318. The correlator powers down or stops the clock according to this gate signal. As described above, the power consumption of this DBF can be reduced. The shift registers 1319 to 1321, the switch 1328, the algorithm 1331, and the MRC 1328 are RA for channel 1 demodulation.
Configure KE reception. Shift registers 1319 to 132
1 holds the time for the number of stages, the shift register 1319 holds the time for the beam 1 component, the shift register 1320 holds the time for the beam 2 component, and the shift register 1321 holds the beam Q.
Hold the time of each ingredient. Shift register 131
The 9-1321 output is provided to switch 1328, where algorithm 1331 adaptively switches 1
On / off of 328 is controlled. Up to five switches are turned on, and the result is combined with the maximum ratio. R as above
Although AKE reception is realized, the number of switches on / off may be 5 or less, or 5 or more. Further, the shift registers 1322 to 1324, the switch 1329, the algorithm 1332, and the MRC 1327 for the channel 2 operate in the same manner, and the shift register 132 for the channel Q
5-1327, switch 1330, algorithm 133
3, the MRC 1336 operates similarly.

[0065]

The transmission power control apparatus according to the present invention has an effect that the channel capacity can be increased because the reception power to interference power density ratio of the high bit rate mobile station and the low bit rate station can be made constant.

In the DMA system according to the present invention, a high bit rate mobile station can be assigned to transmission using a directional antenna and a low bit rate station can be assigned to transmission using an omnidirectional antenna. The antenna reception power of the station can be lowered and the channel capacity can be increased.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a base station according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram showing a common RX means according to the first embodiment of the present invention.

FIG. 3 is a configuration diagram showing a common TX means according to the first embodiment of the present invention.

FIG. 4 is a configuration diagram showing RX processing means for channel 1 according to the first embodiment of the present invention.

FIG. 5 is a configuration diagram showing TX processing means for channel 1 according to the first embodiment of the present invention.

FIG. 6 is a configuration diagram showing common processing means for channel 1 according to the first embodiment of the present invention.

FIG. 7 is a diagram showing a transmission format according to the first embodiment of the present invention.

FIG. 8 is a diagram showing received power of the base station according to the first embodiment of the present invention.

FIG. 9 is a diagram showing a cell configuration of an omnidirectional antenna according to a second embodiment of the present invention.

FIG. 10 is a diagram showing a cell configuration using a directional antenna according to a second embodiment of the present invention.

FIG. 11 is a diagram showing transmission control according to the second embodiment of the present invention.

FIG. 12 is a diagram showing transmission control according to the second embodiment of the present invention.

FIG. 13 is a configuration diagram showing a DBF antenna according to a third embodiment of the present invention.

FIG. 14 is a configuration diagram showing a base station in a conventional transmission power control apparatus.

FIG. 15 is a configuration diagram showing a mobile station in a conventional transmission power control apparatus.

FIG. 16 is a configuration diagram showing a CDMA system using a conventional directional antenna.

FIG. 17 is a configuration diagram showing a conventional CDMA system using a directional antenna.

FIG. 18 is a configuration diagram showing a conventional DBF antenna.

FIG. 19 is a diagram illustrating a problem of conventional transmission power control.

FIG. 20 is a diagram illustrating a problem of conventional transmission power control.

[Explanation of Codes] 101 base station (omnidirectional antenna system), 102 base station (directional antenna system), 103 omnidirectional antenna,
104 directional antenna, 105, 106 transmission / reception separating means, 107, 108 common RX control means, 109, 1
14 common TX control means, 110, 111 adder, 1
12,113 Pilot signal generator, 115,11
6, 117, 118, 119, 120 Modulator / demodulator for each channel, 121, 122 RX processing means, 123, 12
4 comparison means, 125,126 TPC command generation means, 127,128 TX processing means, 129 common control means, 201 LNA, 202 mixer, 203 BP
F, 204 AGC, 205 duplexer, 206, 207
Mixer, 208,209 LPF, 210,211A /
D, 212 local oscillator, 213 phase shifter, 301, 3
02 D / A, 303, 304 LPF, 305, 30
6 mixer, 307, 308 LPF, 309 local oscillator, 310 phase shifter, 311 demultiplexer, 312 VC
Amplifier, 313 mixer, 314 BPF, 315 H
PA, 401, 402 correlator, 403, 404 multiplier, 405, 406 integral discharge, 407, 408 averaging, 409 data recovery, 410 power measurement, 501
Switch, 502 S / P, 503, 504, 505
506 multiplier, 601, 602, 603, 604, 6
05,606 Calculator, 607 Averaging, 701,70
2, 703, 704, 705, 706, 707 information symbols, 708 PN sequence, 801 base station reception power at transmission rate R (omnidirectional antenna), 802 base station reception power at transmission rate 64R (omnidirectional antenna), 803 Base station reception power (directional antenna) at transmission rate 64R, 1001 omnidirectional antenna beam, 1002 directional beam, 1003 base station, 10
04,1005 mobile stations, 1101,1102,110
3,1104,1105 Base station processing, 1106,1
107, 1108, 1109 Mobile station processing, 1301
Element of DBF antenna, 1302 LNA, 1303
Local oscillator, 1304 phase shifter, 1305, 1306
Mixer, 1307, 1308 A / D, 1309 D
BF, 1310, 1311, 1312, 1313, 13
14, 1315, 1316, 1317, 1318 Correlator, 1319, 1320, 1321, 1322, 132
3,1324, 1325, 1326, 1327 shift register, 1328, 1329, 1330 switch,
1331, 1332, 1333 Algorithm, 133
4,1335,1336 MRC.

─────────────────────────────────────────────────── --Continued front page (56) References JP-A-8-79119 (JP, A) JP-A-8-181653 (JP, A) JP-A-7-79475 (JP, A) JP-A-7- 193848 (JP, A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) H04B ^7/ 24-7/26 H04Q ⁷ /00-7/38 H04J 13/00-13/06

Claims (15)

(57) [Claims] 1. A CDMA system for bidirectional communication between a base station equipped with a directional antenna and an omnidirectional antenna, and one or more mobile stations equipped with at least one of an omnidirectional antenna and a directional antenna. in, comprising a reception power by directional antennas of the base station for the mobile station transmit power, the control means receiving power from omnidirectional antennas of the base station is controlled so as like made properly, the control means, Received power of the omnidirectional antenna
Comparing the force with a first reference value and receiving the directional antenna
By comparing the power with the second reference value, the power control
And a transmission power control device. 2. The transmission power control apparatus according to claim 1, wherein the directional antenna is a beamforming antenna. 3. The first reference value and the second reference value are:
The transmission power control device according to claim 1 , wherein the transmission power control device is obtained by a signal power to interference power density ratio of a received signal. 4. The transmission power control apparatus according to claim 1, wherein the base station allocates a directional beam to a mobile station requesting high bit rate transmission. For wherein said high bit rate transmission, than the diffusion gain of the low bit rate transmission, a small spread gain
In transmission power control apparatus according to claim 4, wherein the transmission. 6. The base station is assigned to a mobile station.
A scheme for assigning a predetermined spreading gain according to the bit rate.
The transmission according to claim 4 or 5, characterized in that
Power control device. Wherein said first reference value and second reference value, the transmission power control apparatus according to claim 1, wherein the varied weights more for each channel. 8. A CDMA system for bidirectional communication between a base station equipped with a directional antenna and an omnidirectional antenna, and one or more mobile stations equipped with at least one of an omnidirectional antenna and a directional antenna. in, comprising a reception power by directional antennas of the base station for the mobile station transmission power, the transmission power control means for transmitting power control so that the received power by the non-directional antenna of said base station is equal properly, the The control means is omnidirectional
Compare the received power of the antenna with a first reference value,
To compare the received power of the active antenna with a second reference value
CD characterized by generating more power control commands
MA system. 9. The CDMA system of claim 8 wherein the directional antenna beam overlaps a zone of the omnidirectional antenna. 10. The C according to claim 8, wherein the directional antenna is a beamforming antenna.
DMA system. 11. The directional beam at the base station
When allocating a plurality of mobile stations adjacent to each other,
Claims characterized by being collectively housed in a directional beam
Item 8. The CDMA system according to item 8. 12. The directional beam at the base station
When assigning the
Put different mobile stations together in a directional beam
9. The CDMA system according to claim 8, wherein: 13. The CDMA system according to claim 8 , wherein the directional beam is assigned to the mobile station independently of other beams when there is a beam that can be assigned in the base station. . 14. Assignment of the directional beam to the mobile station, according to claim 8, characterized in that shared with other mobile stations neighboring when assignable beam is not present at the base station CDMA system. 15. A mobile station requesting the high bit rate, at the time of initial transmission performs transmission at a low bit rate, according to claim 8, wherein the use of a control algorithm using the non-directional antenna at the base station CDMA
system.