JP3075341B2 - Transceiver - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmitting / receiving apparatus in a code division multiple access system.

[0002]

2. Description of the Related Art Code division multiple access (hereinafter referred to as CD)
MA) is one of the communication systems using the spread spectrum technology. As a general form, as shown in FIG. 8, for example, a plurality of base stations B1 to B3 and a plurality of base stations B1 to B1 Mobile devices M1 to M5 located in cells corresponding to B3 respectively. Here, the cell is
An area defined for each base station and refers to a fixed area centered on each base station.

In this CDMA system, when a plurality of users (mobile devices; for example, mobile devices M1 and M2) exist within the same frequency and at the same time, an individual spreading code is used for each mobile device. (For example, in the cell corresponding to the base station B1, the mobile device M1 and the mobile device M2 are distinguished). In a CDMA system, as one mode, an FD that performs communication by changing a transmission frequency from the base station to the mobile station (downlink) and a transmission frequency from the mobile station to the base station (uplink).
The D (Frequency Domain Dupulex) method is used. Further, in this CDMA system, transmission power is controlled on the transmission side so that reception is performed at an appropriate desired signal reception power to interference wave reception power ratio (hereinafter, SIR) on the receiver side.

Conventionally, as typical techniques for controlling transmission power on the transmission side so that reception is performed at an appropriate SIR on the receiver side, there are transmission power open loop control and transmission power closed loop control. .

[0005] The transmission power open loop control is to compensate for the reception power that gradually changes in proportion to the distance between the base station and the mobile station. Further, as one form of the conventional transmission power closed-loop control, a reception signal level is detected by an AGC circuit or the like in a receiver on a mobile device side for each mobile device, and attenuation of a transmission path is determined based on the received signal level. Control the transmission signal level to the base station side to compensate for However, especially in a CDMA system, since communication is performed within the same frequency and at the same time as described above, it is necessary to determine how much information about the own mobile station is included in the received signal. Therefore, the transmission power cannot be accurately controlled. As an example that solves such a problem, there is an embodiment disclosed in Japanese Patent Application Laid-Open No. 05-75571 (hereinafter, Conventional Example 1). In the technique according to the aspect, a measuring circuit for measuring an error rate of a received signal is provided on a receiver side, and a signal level attenuation or distortion in a transmission path is predicted based on a measurement result, and a transmission signal to a partner station is transmitted. This is a method of controlling the electric power. Conventional example 1
The other modes in have the same problems as described above.

[0006] Transmission power closed-loop control means that a base station measures the level of a received signal from a mobile station, and, based on the measurement result, includes a signal level in a transmission path in a transmission signal sequence for the mobile station. This is a method in which a control signal for compensating the attenuation of the transmission signal is superimposed, and the mobile station determines a transmission signal level based on the control signal.
As understood from this, the transmission power closed-loop control is a control suitable for a case where the transmitting side finely controls the receiving side (or each receiving side when there are a plurality of receiving sides). Although the method described here relates to uplink transmission power control, a similar method is used for downlink transmission power control. An example of this type is disclosed in
No. 37515 (hereinafter referred to as Conventional Example 2).

[0009] As shown in FIG. 9, the transmission / reception apparatus of the conventional example 2 includes an antenna 101, a transmission / reception separation unit 102, a transmission radio unit 103, a spreading unit 104, a modulation unit 105, a convolutional encoder 106, a signal generation unit 107, Transmission power control bit determination section 501, transmission power control bit extraction section 502, transmission power control section 503, reception radio section 111, despreading section 112, demodulation section 113, SIR calculation section 114, Viterbi decoder 11
5, a simple Viterbi decoder 116.

The transmission / reception separating section 102 is for inputting a reception signal received by the antenna 101 to the reception radio section 111 and transmitting a transmission signal output from the transmission radio section 103 from the antenna 101. .

Radio reception section 111 removes a carrier from a reception signal received via transmission / reception separation section 102 and outputs the signal to despreading section 112.

[0010] Despreading section 112 receives the received signal from which the carrier has been removed from reception radio section 111, generates a replica of the spread code in the transmitter on the other side, and converts the received signal using the replica of the spread code. The signal is converted into a despread signal, and a received signal as a despread signal is output. Also, the despreading unit 112 receives a desired signal received power (hereinafter, RSSI) of the received signal.
Call. ) For detecting the desired signal reception power 11
8 and an interference wave reception power detection unit 119 for detecting the interference wave reception power (hereinafter, referred to as ISSI) of the reception signal.

[0011] Demodulation section 113 receives the demodulated received signal from despreading section 112 and demodulates the received signal.

The Viterbi decoder 115 performs error correction on the received signal demodulated by the demodulator 113 and extracts information data such as traffic channels contained in the received signal sequence.

On the other hand, the simplified Viterbi decoder 116 has a shorter constraint length than the Viterbi decoder 115, and the demodulator 1
13 and performs decoding faster than the Viterbi decoder 115 on the received signal and outputs an error-corrected received signal.

The transmission power control bit extracting section 502 receives the error-corrected received signal from the simple Viterbi decoder 116, extracts bit information for transmission power control inserted in the received signal sequence, and Output to the control unit 503.

Transmission power control section 503 determines transmission power according to bit information for transmission power control and controls the power of a transmission signal transmitted from transmission radio section 103.

Further, the SIR calculation section 114 determines whether the despreading section 1
12 receives the RSSI and ISSI of the received signal detected by the desired signal reception power detection section 118 and the interference signal reception power detection section 119, respectively.
Is calculated and output to the transmission power control bit determination unit 501.

[0017] The transmission power control bit determination unit 501 uses the SI
Based on the SIR of the received signal calculated by R calculation section 114, a transmission power control bit for instructing the other station transmission section to increase or decrease the transmission power is determined, and the transmission power control bit is determined by signal generation section 107. Output to More specifically, if the SIR is small, transmission power control bit determination section 501 outputs a transmission power control bit for instructing a partner station transmission section to increase transmission power to signal generation section 107, If the SIR is large, a transmission power control bit for instructing the transmission unit of the other station to lower the transmission power is output to signal generation unit 107.

Signal generation section 107 generates a transmission signal sequence, receives the transmission power control bits from transmission power control bit determination section 501, inserts the transmission power control bits into the transmission signal sequence, and generates a convolutional code. Output to the container 106.

Convolutional encoder 106 receives the transmission signal sequence in which the transmission power control bit is inserted, encodes the transmission signal sequence, and outputs the encoded signal to modulation section 105.

[0021] Modulation section 105 receives the coded transmission signal sequence, performs primary modulation, and outputs the result to spreading section 104.

Spreading section 104 receives the primary modulated transmission signal sequence from modulation section 105, performs spread modulation, and transmits a transmission signal as a spread spectrum signal to transmission radio section 103.
Output to

Transmission radio section 103 includes transmission power control section 50
The transmission power received from the spreading section 104 is determined by the transmission / reception separating section 1 using the determined transmission power.
02 and the antenna 101 to transmit to the mobile device (the other station).

[0023]

However, the transmission / reception devices disclosed in the above-mentioned prior art examples 1 and 2 have various problems. Hereinafter, those problems will be described with reference to FIG.

The problem with the transmitting / receiving device of the conventional example 2 is as follows.
It is related to the characteristics of the closed loop control. In general, closed-loop control is performed by transmitting information for transmission power control at the next transmission from the receiving side to the transmitting side, but the information for transmission power control is transmitted accurately. If it is not performed, there is naturally a risk that a malfunction of the transmission power control will occur on the transmission side at the next transmission. Therefore, in a situation where it is not necessary to perform the closed-loop control, that is, when the quality of the received signal is equal to or higher than a certain value, it is preferable that the closed-loop control is not performed as much as possible. For example, when the mobile station is not subjected to interference from other cells and the like, if the transmission power of transmission from the base station side to the mobile station side is controlled by closed-loop control, it is related to the risk described above, and the communication quality is rather changed. Therefore, it is desirable not to perform the closed loop control. However, in the transmitting and receiving apparatus of the second conventional example, such a situation cannot be controlled in a distinctive manner.

The required circuit configuration is different between the case where interference is not received from other cells and the case where interference is not received. In particular, when there is no interference from other cells, the required circuit configuration is relatively small. What is necessary is just to have a simple circuit.
That is, in the case where interference is not received from another cell, a circuit with lower power consumption can be used as compared with the case where interference is received. However, the transmission / reception apparatus of the conventional example 2 consumes extra power because the circuit for receiving interference is operated even when interference is not received from other cells. Considering that the machine is driven by a battery, there is a problem that the time during which information can be transmitted (mainly, a call) is shortened.

Here, the interference from another cell indicates the following. In FIG. 8, when attention is paid to the transmission in the downlink direction, for example, the signals from the base station B1 to the two mobile stations M1 and M2 are signals in which the corresponding spreading codes are orthogonal to each other. Working below. Therefore, the transmissions to the respective mobile units M1 and M2 are synchronized in timing and do not cause interference as in the problem. However, for example, transmission performed from the base station B1 to the mobile station M2 includes transmission performed from the base station B2 different from the base station B1 to the two mobile stations M3 and M4, and transmission performed from the base station B3 to the mobile station M2. The transmission performed on M5 will cause interference. This is because in a CDMA system, the distinction between base stations is performed using a spreading code (periodically longer than for user distinction), as in the case of user (mobile station) distinction. This is because the transmission timing between them is asynchronous. As described above, interference received from a base station different from the base station to which the base station belongs (or a cell corresponding to the base station) due to the asynchronous transmission timing between the base stations is referred to as interference from another cell.

The transmission and reception relationship within the own cell is as follows. First, focusing on transmission / reception on the base station side, since there is a relationship of n transmissions (n mobile stations) for one reception (for example, base station B1), the position and distance of each mobile station Accordingly, the level of the received signal on the base station side fluctuates greatly.
That is, since the transmission timing of the mobile station is synchronized with the signal received from the base station, the transmission timing is faster if the mobile station is located closer to the base station, and is slower if the mobile station is located farther from the base station. It will be. Since the base station receives these composite waves, in other words, it receives a composite wave of signals transmitted at different timings. Therefore, for example, on the base station side, the base station controls each mobile station so that the mobile station corresponding to the strongly received signal is weak, and the mobile station corresponding to the weakly received signal is strongly transmitted. It is necessary to make the signal level corresponding to each mobile device on the base station side equal. Further, in order for each of the plurality of mobile stations to transmit and receive a stable signal, high-speed performance is required for the transmission power control. Focusing on transmission and reception on the mobile device side, there is a relationship of one transmission (base station B1) to one reception (for example, mobile device M1). That is, regarding the transmission from the base station to each mobile station, the timing is the same,
There is no problematic interference in its own cell,
Since it is governed only by the positional relationship between its own mobile station and the base station, there is no large level fluctuation of the received signal unlike the base station. Therefore, when there is no interference from other cells (for example, the mobile device M1), the mobile device only needs to perform power control in accordance with a gradual reception power fluctuation due to its own moving time and distance. (For example, the mobile device M2),
As described above, closed-loop control is performed to cancel interference from another base station with respect to a mobile station belonging to another cell.

The problem of the transmission / reception device of the prior art example 1 is that it takes too much time to perform high-precision control, which is not practical. That is, the relationship between the bit error rate and Eb / N0 (a signal equivalent to the SIR signal), which is a characteristic of the first conventional example, is a characteristic that can be obtained only after a long time measurement and further averaging. Therefore, even if the error rate (bit error rate) is measured, Eb / N0 (or SIR) is not uniquely determined in a short time measurement. Therefore, in order to perform high-precision control, measurement for a considerably long time is required.
In other words, in order for the base station to control each mobile station,
Since high speed is required, Conventional Example 2 cannot satisfy the demand.

An object of the present invention is to provide a transmission / reception apparatus that can realize stable communication quality with a minimum necessary circuit in a code division multiple access system using spread spectrum.

[0030]

According to the present invention, in order to solve the above-mentioned problems, closed-loop control is performed for uplink transmission power control, while open-loop control or The decision was made to use open-loop control and closed-loop control separately. Specifically, the present invention provides the following means.

That is, according to the present invention, there is provided a transmitting / receiving apparatus in a code division multiple access system having at least one base station and a plurality of mobile stations, wherein different spreading codes are used for each mobile station, In the base station-side transmitting / receiving device, which is the transmitting / receiving device on the base station side, when downlink transmission power control information is included in the received signal sequence from the mobile station, the downlink transmission power control information is extracted. Extracting means, measuring means for measuring the quality of a received signal received from the mobile device, and generating uplink transmission power control information to be transmitted to the mobile device according to the measurement result of the measuring device. A generating unit, which is connected to the extracting unit and the generating unit, and outputs one of the downlink transmission power control information extracted by the extracting unit and the uplink transmission power control information generated by the generating unit; And a transmission power control unit for controlling transmission power of a downlink transmission signal to the mobile station according to the one of the transmission power control information selected by the selection means. A station side transmitting / receiving device is obtained.

Further, according to the present invention, there is provided a transmitting / receiving apparatus in a code division multiple access system having at least one base station and a plurality of mobile stations, wherein different spreading codes are used for each mobile station, In the mobile device side transmitting / receiving device which is the mobile device side transmitting / receiving device, storage means for holding a threshold value related to the quality of the received signal received from the base station, and measuring the quality of the received signal received from the base station Measuring means for averaging the quality measured by the measuring means for a predetermined time, and comparing the averaged quality with the threshold value stored in the storage means. Means, and generating means for generating downlink transmission power control information to be transmitted to the mobile station according to the measuring means and the comparing means. Communication apparatus can be obtained.

Further, according to the present invention, in the transmitting / receiving apparatus on the mobile device side, the generating means stores the quality of the received signal measured by the measuring means in the storage means in accordance with a result of the comparison by the comparing means. If the threshold value is higher than the stored threshold value, the operation of generating the downlink transmission power control information is stopped.

Here, the base station side transmitting / receiving apparatus and the mobile station side transmitting / receiving apparatus are used in the same communication system.

Further, according to the present invention, there is provided a transmitting / receiving apparatus in a code division multiple access system having at least one base station and a plurality of mobile stations, wherein different spreading codes are used for each mobile station, In the base station-side transmitting / receiving device, which is the transmitting / receiving device on the base station side, measuring means for measuring the quality of the received signal received from the mobile device, and transmitting to the mobile device according to the measurement result of the measuring device. A base station comprising: generating means for generating uplink transmission power control information to be transmitted; and a transmission power control unit that controls transmission power of a downlink transmission signal to the mobile station according to the uplink transmission power control information. A side transmitting / receiving device is obtained.

[0036]

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

(First Embodiment) The transmitting and receiving apparatus according to the first embodiment of the present invention has different configurations on the base station side and the mobile station side. Therefore, the base station side transmitting / receiving apparatus will be described first, and then the mobile station side transmitting / receiving apparatus will be described.

As shown in FIG. 1, the base station-side transmitting / receiving apparatus of this embodiment includes an antenna 101, a transmission / reception separating unit 10
2, transmission radio section 103, spreading section 104, modulation section 105,
Convolutional encoder 106, signal generation section 107, uplink transmission power control bit determination section 108, downlink transmission power control bit extraction section 109, transmission power control section 110, reception radio section 11
1, despreading unit 112, demodulation unit 113, SIR calculation unit 11
4, a Viterbi decoder 115, a simple Viterbi decoder 116, and a power control information switch 117.

Transmission / reception separating section 102 is for inputting the reception signal received by antenna 101 to reception radio section 111 and transmitting the transmission signal output from transmission radio section 103 from antenna 101. .

Radio reception section 111 removes a carrier from a reception signal received via transmission / reception separation section 102 and outputs the signal to despreading section 112.

Despreading section 112 receives the reception signal from which the carrier has been removed from reception radio section 111, generates a replica of the spread code in the transmitter on the other side, and converts the received signal using the replica of the spread code. The signal is converted into a despread signal, and a received signal as a despread signal is output. Also, the despreading unit 112 receives a desired signal received power (hereinafter, RSSI) of the received signal.
Call. ) For detecting the desired signal reception power 11
8 and an interference wave reception power detection unit 119 for detecting the interference wave reception power (hereinafter, referred to as ISSI) of the reception signal.

[0042] Demodulation section 113 receives the demodulated reception signal from despreading section 112 and demodulates the received signal.

The Viterbi decoder 115 corrects the error of the received signal demodulated by the demodulator 113 and extracts information data such as traffic channels contained in the received signal sequence.

On the other hand, the simple Viterbi decoder 116 has a shorter constraint length than the Viterbi decoder 115, and
13 and performs decoding faster than the Viterbi decoder 115 on the received signal and outputs an error-corrected received signal.

The downlink transmission power control bit extraction section 109
Upon receiving the error-corrected received signal from the simple Viterbi decoder 116, the following four types of signals are output to the power control switch 117. The first to third signals are signals output when bit information for downlink transmission power control is inserted in the received signal sequence, and include “increase downlink transmission power” and “downlink transmission power”. Maintain the transmission power as it is ",
It is provided with downlink transmission power control bit information having any one of the three meanings of “lowering downlink transmission power”. The fourth signal is a signal that is output when downlink transmission power control bit information is not inserted into the signal sequence, and indicates that "the mobile station does not transmit downlink transmission power control bit information, "Use power control bit information instead."

Further, the SIR calculation section 114 determines that the despreading section 1
12 receives the RSSI and ISSI of the received signal detected by the desired signal reception power detection section 118 and the interference signal reception power detection section 119, respectively.
Is calculated and output to uplink transmission power control bit determination section 108.

The uplink transmission power control bit determination section 108
Based on the SIR of the received signal calculated by the SIR calculation section 114, the uplink transmission power control bit information for instructing the transmission section on the mobile device side to increase or decrease the transmission power is determined. Information to the signal generator 107
And output to the power control switch 117. More specifically, as shown in FIG. 2, the uplink transmission power control bit determination unit 108 determines a reference SIR value (or range).
Storage unit 1081 that stores a reference SIR value (range)
Receiving the SIR of the received signal from the SIR calculating section 114, comparing and determining the received SIR with a reference SIR value (range) stored in the storage section, and outputting a determination result; and a determination result from the determination section 1082. And a control bit generation unit 1083 that generates uplink transmission power control bit information which means to increase, decrease, or maintain the uplink transmission power as it is. Further, uplink transmission power control bit determination section 108 receives reception signal SIR from SIR calculation section 114 and, if the SIR is small, instructs mobile station side transmission section to increase uplink transmission power. The uplink transmission power control bit information is transmitted to the signal generator 107.
And the power control switch 117. If the SIR is large, the uplink transmission power control bit information for instructing the mobile station side transmission section to reduce the uplink transmission power is output to the signal generation section 107 and the power generation section. Output to the control switch 117.

Power control switch 117 receives four types of signals from downlink transmission power control bit extraction section 109 and uplink transmission power control bit information from uplink transmission power control bit determination section 108 and outputs downlink transmission power control bit information. Control bit extraction unit 1
In the case where the signal from D.09 includes downlink transmission power control bit information, downlink transmission power control bit information is output to transmission power control section 110, and the signal from downlink transmission power control bit extraction section 109 is If the transmission power control bit information is not provided, the transmission power control bit information is output to the transmission power control unit 110. More specifically, the power control switch 117 includes a buffer 1171 and a control switch 1172 as shown in FIG. The buffer 1171 receives the uplink transmission power control bit information from the uplink transmission power control bit determination unit 108 and temporarily stores the uplink transmission power control bit information. Control switching section 1172 receives the signal from downlink transmission power control bit extraction section 109,
If the signal has downlink transmission power control bit information, the signal is output to transmission power control section 110, while if the signal does not have downlink transmission power control bit information, This is for outputting the uplink transmission power control bit information temporarily stored in the buffer 1171 to the transmission power control section 110 instead of the signal.

Transmission power control section 110 determines the downlink transmission power according to the output of power control switch 117 and controls the power of the downlink transmission signal transmitted from transmission radio section 103 to the mobile station.

Signal generation section 107 generates a transmission signal sequence, receives uplink transmission power control bit information from uplink transmission power control bit determination section 108, and generates the transmission signal sequence for the transmission signal sequence. And outputs the result to the convolutional encoder 106.

Convolutional encoder 106 receives the transmission signal sequence in which the transmission power control bit is inserted, encodes the transmission signal sequence, and outputs the encoded signal to modulation section 105.

Modulation section 105 receives the encoded transmission signal sequence, performs primary modulation, and outputs the result to spreading section 104.

Spreading section 104 receives the primary modulated transmission signal sequence from modulation section 105, performs spread modulation, and transmits the transmission signal as a spread spectrum signal to transmission radio section 103.
Output to

Transmission radio section 103 includes transmission power control section 11
0 and determines the downlink transmission power according to the control of
Is transmitted to the mobile station (the other station) via the transmission / reception separating unit 102 and the antenna 101 at the determined downlink transmission power.

On the other hand, as shown in FIG. 4, the mobile-station-side transmitting / receiving apparatus of the present embodiment includes an antenna 101, a transmitting / receiving separating section 102, a transmitting radio section 103, a spreading section 104, and a modulating section 10.
5, convolutional encoder 106, signal generation section 107, downlink transmission power control bit determination section 204, uplink transmission power control bit extraction section 205, transmission power control section 201, reception radio section 1
11, despreading unit 112, demodulation unit 113, SIR calculation unit 2
03, Viterbi decoder 115, simplified Viterbi decoder 116,
An SIR threshold register 202, an integrator 206, and a comparator 207 are provided. Here, in FIG. 4, components that perform the same operations as the components in the base station-side transmitting / receiving device are denoted by the same reference numerals (however, except for the signal generating unit 107). Further, description of the components having the same reference numerals will be omitted. In the description, “up” means “down” and “down” means “up”.
, "Mobile station" should be read as "base station", and "base station" should be read as "mobile station".

The uplink transmission power control bit extracting section 205
Upon receiving the error-corrected received signal from the simple Viterbi decoder 116, the following three types of signals are output to the transmission power control unit 201. Each of the first to third signals is one of three types of uplink transmission power control: “increase uplink transmission power”, “maintain uplink transmission power”, and “decrease uplink transmission power”. It has bit information.

Transmission power control section 201 determines the uplink transmission power according to the output of uplink transmission power control bit extraction section 205 and controls the power of the uplink transmission signal transmitted from transmission radio section 103 to the base station.

The components from the SIR calculating section 203 to the signal generating section 107 will be described below. However, the mobile station side and the base station side have different configurations for the following reasons. That is, the SIR of the received signal on the mobile device side usually does not cause a rapid change in the SIR because the signal to the other mobile device and the signal to the own mobile device which become interference waves reach the same route. . Therefore, a threshold value serving as a reference is determined for the SIR of the received signal, and power control is performed only when the SIR of the received signal falls below the threshold value.

[0059] The SIR threshold register 202 stores a threshold determined for the SIR of the received signal.

The SIR calculation section 203 calculates the RS of the reception signal detected by the desired-wave reception power detection section 118 and the interference-wave reception power detection section 119 included in the despreading section 112.
Upon receiving SI and ISSI, the ratio, that is, SIR, is calculated and output to downlink transmission power control bit determination section 204 and integrator 206.

The integrator 206 integrates the output of the SIR calculation section 203 for a certain period of time and averages it.

The comparator 207 outputs the output of the integrator 206 and
A comparison is made with the threshold value stored in the SIR threshold value register 202, and if the SIR of the received signal is equal to or greater than the threshold value, an operation stop signal is transmitted to the downlink transmission power control bit determination unit 204. . Note that the operation stop signal may have two values of on and off, and the comparator 207 may output an operation stop signal having either an on or off value.

The downlink transmission power control bit determination section 204
In response to the SIR of the received signal output from the SIR calculation unit 203 and the output of the comparator 207, one of the following operations is performed according to the operation stop signal. That is, when an operation stop signal is input (or when an operation stop signal having an ON value is input), the downlink transmission power control bit determination unit 204
Stops the operation of determining the control bits and does not transmit the downlink transmission power control bits to the base station.
On the other hand, when the operation stop signal is not input (or when the operation stop signal having an OFF value is input), the downlink transmission power control bit determination unit 204 determines the uplink transmission power control bit determination unit in the base station transmitting / receiving apparatus. Similarly to 108, downlink transmission power control bit information that means to increase, decrease, or maintain the downlink transmission power is determined and output to the signal generator 107. For more information,
As shown in FIG. 5, the downlink transmission power control bit determination unit 204 includes a storage unit 2041, a determination unit 2042, a control bit generation unit 2043, and an operation stop control unit 2044. The storage unit 2041 and the determination unit 2042
Uplink transmission power control bit determination unit 1 of base station side transmitting / receiving apparatus
08 is the same as the storage unit 1081 and the determination unit 1082. The operation stop control unit 2044 is an operation stop signal from the comparator 207 (or an operation stop signal having an ON value).
Accordingly, the operation of the control bit generation unit 2043 is stopped. Control bit generator 2043
Is to stop the operation according to the control of the operation stop control unit 2044 or perform the same operation as that described on the base station side to generate the downlink transmission power control bit information.

Signal generation section 107 generates an uplink transmission signal sequence and, when receiving downlink transmission power control bit information from downlink transmission power control bit determination section 204, performs downlink transmission on the uplink transmission signal sequence. Power control bit information is inserted and output to convolutional encoder 106.

In the communication system having the base station-side transmission / reception device and the mobile device-side transmission / reception device of the present embodiment having such a configuration, only when the reception SIR at the mobile device falls below the threshold value, Since closed-loop control is performed on the downlink transmission power, it is possible to reduce malfunctions when information for transmission power control is not accurately transmitted as in the conventional example. Therefore, in the present embodiment, the communication quality can be improved.

Further, in the present embodiment, when the reception SIR at the mobile device side is equal to or greater than the threshold value, the operation of some functions of the transmission / reception device at the mobile device side can be stopped, thereby reducing power consumption. Become. Therefore, in particular, in a mobile device side transmitting / receiving device using a battery or the like, signal transmission / reception (call)
The time can be extended.

(Second Embodiment) A transmitting / receiving apparatus according to a second embodiment of the present invention has a structure as shown in FIGS.
The base station side and the mobile device side have different configurations. In the present embodiment, the mobile station side transmitting / receiving apparatus does not calculate the SIR, and therefore does not determine the downlink transmission power control bit information. Accordingly, the base station-side transmitting / receiving apparatus controls the power of the downlink transmission signal using the uplink transmission power control bit information. Further, each of the base station side and the mobile device side includes many components similar to those of the first embodiment. Therefore, in FIG. 6 and FIG. 7, the same operations as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

As shown in FIG. 6, the base station side transmitting / receiving apparatus according to the present embodiment includes a simplified Viterbi decoder 116 and a downlink transmission power control bit extracting unit 10 according to the first embodiment.
9 and the power control switch 117 are omitted.

The uplink transmission power control bit determining section 108
Receiving the received signal SIR from the SIR calculation section 114, the uplink transmission power control bit information is determined in the same manner as in the first embodiment, and the signal generation section 107 and the transmission power control section 30 are determined.
Output for 1

Transmission power control section 301 receives uplink transmission power control bit information from uplink transmission power control bit determination section 108 and performs downlink transmission according to the uplink transmission power control bit information instead of downlink transmission power control bit information. It is for controlling electric power.

On the other hand, as shown in FIG. 7, the transmission / reception apparatus on the mobile device side according to the present embodiment employs S in the first embodiment.
It has a configuration in which the IR calculation unit 203, the SIR threshold register 202, the integrator 206, the comparator 207, and the downlink transmission power control bit determination unit 204 are omitted.

In the transmitting / receiving apparatus at the mobile station side of the present embodiment, since the SIR is not calculated, the despreading section 1
Reference numeral 12 has a configuration in which the desired wave reception power detection unit 118 and the interference wave reception power detection unit 119 are omitted.

In the communication system having the base station-side transmitting / receiving apparatus and the mobile station-side transmitting / receiving apparatus of the present embodiment having such a configuration, it is possible to reduce the number of circuits for each transmitting / receiving apparatus.

[0074]

As described above, according to the present invention, the open-loop control is performed for the downlink transmission power control, or the closed-loop control is performed only when the quality of the received signal on the mobile device side falls below a certain value. Since the control is performed, the risk associated with the closed loop control can be reduced, and the communication quality can be improved.

Further, according to the present invention, the number of operating circuits can be temporarily or constantly reduced in the mobile-station-side transmitting / receiving apparatus as compared with the conventional example, so that the duration of information transmission (communication) can be extended. Can be achieved.

According to the present invention, even when performing open loop control as downlink transmission power control, it is not necessary to newly provide a circuit for open loop control. This is because the uplink transmission signal includes information indicating the state of the mobile station as viewed from the base station. For example,
If the base station can receive the transmitted signal from the mobile device strongly, it indicates that the mobile device is in a position with good visibility or is very close, and if the signal is weakly received, the mobile device is in the distance or is under shadow. It indicates that you are in. Therefore,
In the present invention, uplink transmission power control bit information can be applied to downlink transmission power control, and communication quality can be improved without increasing the circuit scale.

Further, in the present invention, even when performing open-loop control as downlink transmission power control, information for uplink transmission power control is diverted, so that higher speed is achieved as compared with the conventional example. .

Further, according to the present invention, in the transmission / reception apparatus on the base station side, finer transmission power control is performed for each mobile station with respect to downlink transmission power control than in open loop control using an error rate or the like. Therefore, unnecessary power is not transmitted to a mobile station located near the base station, and power consumption in the base station side transmitting / receiving apparatus can be reduced. Further, as the transmission power to a mobile station located nearby decreases, the interference power to other cells can also be reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a base station side transmitting / receiving apparatus according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of an uplink transmission power control bit determination unit in FIG.

FIG. 3 is a block diagram illustrating a configuration of a power control switch in FIG. 1;

FIG. 4 is a block diagram illustrating a configuration of a mobile device-side transmission / reception device according to the first embodiment of the present invention.

FIG. 5 is a block diagram showing a configuration of a downlink transmission power control bit determination unit in FIG.

FIG. 6 is a block diagram illustrating a configuration of a base station-side transmitting / receiving apparatus according to a second embodiment of the present invention.

FIG. 7 is a block diagram illustrating a configuration of a mobile device-side transmitting / receiving device according to a second embodiment of the present invention.

FIG. 8 is a diagram illustrating one embodiment of a code division multiple access system.

FIG. 9 is a block diagram illustrating a configuration of a transmission / reception device of Conventional Example 2.

[Explanation of symbols]

 Reference Signs List 101 antenna 102 transmission / reception separation unit 103 transmission radio unit 104 spreading unit 105 modulation unit 106 convolutional encoder 107 signal generation unit 108 uplink transmission power control bit determination unit 109 downlink transmission power control bit extraction unit 110 transmission power control unit 111 reception radio unit 112 Despreading unit 113 Demodulation unit 114 SIR calculation unit 115 Viterbi decoder 116 Simple Viterbi decoder 117 Power control switch 1081 Storage unit 1082 Judgment unit 1083 Control bit generation unit 1171 Buffer 1172 Control switching unit 201 Transmission power control unit 202 SIR threshold Value register 203 SIR calculation section 204 downlink transmission power control bit determination section 205 uplink transmission power control bit extraction section 206 integrator 207 comparator 2041 storage section 2042 determination section 2043 control bit generation section 2044 operation Stop control unit 301 transmission power control section 401 despreader

Claims (1)

(57) [Claims] 1. A transmission / reception apparatus in a code division multiple access system having at least one base station and a plurality of mobile stations, wherein a different spreading code is used for each of the mobile stations, wherein the transmission / reception on the base station side is performed. In the base station side transmitting / receiving device, which is a device, when downlink transmission power control information is included in the received signal sequence from the mobile device, an extracting unit for extracting the downlink transmission power control information, Measuring means for measuring the quality of a received signal received from the mobile device; generating means for generating uplink transmission power control information to be transmitted to the mobile device according to the measurement result of the measuring device; Means for selecting one of the downlink transmission power control information extracted by the extraction means and the uplink transmission power control information generated by the generation means, connected to the means and the generation means. If, according to the selected said one of the transmission power control information of said selection means, the base station side transmitting and receiving apparatus, characterized in that it comprises a transmission power controller for controlling transmission power of the downlink transmission signal to the mobile station.