JPH09214407A - Diversity communication equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain high data transmission quality with low power consumption and a simple device without deterioration frequency use efficiency by setting the transmission carrier frequencies of plural signals which are to be transmitted for the respective signals in accordance with the detection result of the signal transmission quality of the respective carrier frequencies. SOLUTION: The signals outputted from outside are inputted to a signal distributor 320. The signal distributor 320 refers to the transmission quality of this carrier frequencies informed by a frequency quality storage unit 318 and are selected by a carrier frequency selector 316. When the transmission quality is satisfactory, the signal whose requested channel quality is high is outputted to a modulator 313 among the inputted signals and the signal whose requested channel quality is low among the inputted signals. The frequency of satisfactory transmission quality is allocated to the signal whose requested channel quality is higher by time-divisionally using the carrier frequency so as to transmit it. Thus, satisfactory information transmission quality can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a diversity communication system used in digital communication, and more particularly to a diversity communication device capable of efficiently performing communication with a required transmission quality even on a line that causes fading.

[0002]

2. Description of the Related Art In a radio communication line such as a mobile communication system that may cause severe fading, a spatial diversity receiving system in which a plurality of independent antennas are used to improve the deterioration of signal transmission characteristics due to fading. Is widely used.

Further, in a communication system using the TDD system, a reception signal from a communication partner station and a transmission signal to a communication partner station are adjacently propagated in a propagation path at a short time interval. There is known a transmission diversity system that can improve the reception quality of a communication partner station by transmitting using an antenna having a good reception quality, which can ignore the state change of the propagation path during this period.

In the mobile communication system, the reception and transmission diversity method is applied to the base station apparatus from the viewpoint of simplification of the mobile station apparatus, and the uplink from the mobile station to the base station is increased without increasing the apparatus size of the mobile station. Generally, a method of improving the quality of both the downlink from the base station to the mobile station is adopted.

FIG. 7 is a block diagram showing an example of the configuration of a mobile communication device using the conventional TDD system. here,
An example is shown in which base station 100 uses two antennas to perform space diversity. FIG. 8 shows a signal format when bidirectional communication is performed by the TDD method using this type of device. As shown in the figure, the base station and the mobile station perform bidirectional communication by alternately transmitting and receiving upstream signals and downstream signals in time.

In FIG. 7, the antenna 1 of the base station 100
The upstream signals received by 01 and 102 are input to the corresponding switches 103 and 104, respectively. The switches 103 and 104 are switches that switch the connection destination of the antenna during reception and during transmission in TDD communication. At the time of receiving the upstream signal, the received signal is received by the receivers 105 and 1 corresponding to the switches 103 and 104, respectively.
It is input to 06.

The received signals output from the receivers 105 and 106 correspond to the received signal strength detectors 10 respectively.
9 and 110, and demodulators 107 and 108
Are also input respectively. Then, each received signal strength detected by each received signal strength detector 109, 110,
That is, the detection result of each reception quality is input to the comparator 111.

The comparator 111 compares the signal strengths detected by the respective received signal strength detectors and sets the switch 112 so that the demodulated signal obtained from the demodulator corresponding to the antenna having a high signal strength is output. To do. Comparator 111
Makes the same setting for the switch 115 and fixes this setting immediately before the end of the upstream signal. By fixing the setting in this way, the switch 115 is connected to the antenna side having a high received signal strength when transmitting the upstream signal.

Next, when transmitting a downlink signal from the base station 100, a signal inputted from the outside is modulated by the modulator 113 and further becomes a transmission signal by the transmitter 114. The output of the transmitter 114 is connected to the switch 103 or 104 side fixed by the switch 115 as described above, and is transmitted from the corresponding antenna 101 or 102.

On the other hand, in the mobile station 200, the downlink signal is received by the antenna 201 and input to the switch 202. The switch 202 is the switch 103, 1 in the base station.
Similar to 04, the connection destination is switched between transmission and reception. The received signal is input to the receiver 203 when the downlink signal is received.

The received signal output from the receiver 203 is
It is demodulated by the demodulator 205 and output. The signal input from the outside during the uplink signal transmission from the mobile station is
The signal is modulated by the modulator 206 and further becomes a transmission signal by the transmitter 204, and the antenna 2 is transmitted via the switch 202.
Sent from 01.

[0012]

In the conventional device as described above, for example, like image data and audio data,
When data with different required channel quality is transmitted alternately or simultaneously on one channel, it is necessary to set the channel quality to the higher required channel quality (usually image data is transmitted. The required line quality is higher than that required when transmitting voice data).

In other words, in order to transmit data requiring high channel quality with good quality, the number of antennas of the base station is increased to increase diversity gain, frequency diversity is used, or the base station and mobile station are used. It has been necessary to increase the transmission power and make settings so that high line quality can be obtained for the entire circuit.

However, the method of increasing the number of antennas has a problem that the device scale of the base station becomes large, and the method of using frequency diversity has a problem that the frequency utilization efficiency is deteriorated. The method of increasing the transmission power of the mobile station has a problem that the power consumption increases. And, this is an unfavorable problem especially in a mobile station that is required to be small and lightweight.

The present invention has been made to solve the above problems, and an object of the present invention is to achieve high data transmission without deteriorating frequency utilization efficiency with a low power consumption and a simple device. It is to provide a diversity communication device that can obtain quality.

[0016]

According to the present invention, the above-mentioned object is solved by the means described in the claims.

That is, the invention of claim 1 is a diversity communication apparatus comprising a first transceiver and a second transceiver for transmitting and receiving the first transceiver, wherein the first transceiver includes a second transceiver. Receiving means for receiving each of a plurality of signals transmitted by using a plurality of carrier frequencies different transmitter and receiver, and measuring the reception quality of each received signal received by the receiving means,

From the measurement result, signal transmission quality detecting means for detecting the signal transmission quality for each carrier frequency, and transmission according to the detection result of the signal transmission quality of each carrier frequency obtained by the signal transmission quality detecting means A diversity communication device comprising setting means for setting the transmission carrier frequencies of a plurality of signals to be set for each signal, and transmission means for transmitting the signals at the transmission carrier frequencies set by the setting means. .

According to a second aspect of the present invention, in the diversity communication apparatus according to the first aspect, the first transmitter / receiver detects the signal transmission quality at each carrier frequency obtained by the signal transmission quality detecting means, or In addition to the detection result notifying means for notifying the second transceiver of the value indicating the relative quality of the transmission quality of each frequency,

Transmission quality recognition means for recognizing the detection result of the signal transmission quality of each carrier frequency notified from the first transceiver to the second transceiver, and each carrier recognized by the signal transmission quality recognition means Setting means for setting the transmission carrier frequency of a plurality of signals to be transmitted according to the detection result of the signal transmission quality of frequency for each signal, and each signal at each transmission carrier frequency of each signal set by the setting means Is a diversity communication device including:

According to a third aspect of the present invention, in the diversity communication device according to the first or second aspect, a plurality of input transmission signals are input to the first transceiver according to the required high transmission quality. And a setting means of the first transmitter / receiver that requires higher transmission quality among a plurality of types of transmission signals divided by the dividing means, the signal transmission quality The diversity communication device includes a carrier frequency designating unit that designates to set a carrier frequency having good signal transmission quality of the carrier frequency obtained by the detecting unit.

According to a fourth aspect of the present invention, in the diversity communication device according to the second or third aspect, a plurality of input transmission signals are input to the second transceiver according to the required high transmission quality. And a dividing means for dividing into a plurality of signal groups,
A signal transmission of the carrier frequency recognized by the signal transmission quality recognizing means for a signal requiring higher transmission quality among the plurality of types of transmission signals divided by the dividing means, to the setting means of the second transceiver. The diversity communication device includes a carrier frequency designating unit that designates to set a high-quality carrier frequency.

The main feature of the present invention is that the frequency diversity effect can be obtained without lowering the frequency utilization efficiency by using a plurality of frequencies in a time division manner as compared with the prior art. According to the present invention, frequencies having different transmission qualities are assigned to the respective signals of the plurality of signals to be transmitted and the signals are transmitted, so that high information transmission quality can be obtained due to the frequency diversity effect.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A description will now be given, with reference to the drawings, of how the present invention is actually implemented. FIG.
FIG. 3 is a block diagram showing a first example of an embodiment of the present invention. FIG. 2 shows an example of a signal format when bidirectional communication is performed by the TDD method using this device.
As shown in the figure, the base station and the mobile station perform bidirectional communication by alternately transmitting and receiving upstream signals and downstream signals in time.

In FIG. 1, the antenna 3 of the base station 300
The upstream signal received by 01 is input to the switch 303. The switch 303 is a switch that switches the connection destination of the antenna depending on whether it is receiving or transmitting in TDD communication. When receiving the upstream signal, the received signal is
The receiver 305 receives the signal of the carrier input from the switch 303 to the receiver 305 and notified by the carrier frequency selector 316.

The carrier frequency selector 316, as shown in FIG. 2, selects the carrier frequency to be used during reception and transmission and outputs the information. At the same time, the carrier frequency information of the carrier frequency selector 316 is input to the frequency quality memory 318. Further, at the time of transmission, the carrier frequency selector 316 inputs the carrier frequency information used at the time of transmission to the signal distributor 315 and the transmitter 314.

The received signal output from the receiver 305 is
It is input to the received signal strength detector 309 and also to the demodulator 307. The received signal strength detector 309 is
The signal strength of the reception signal output from the receiver 305 is detected. Then, the reception signal strength detected by the reception signal strength detector 309, that is, the detection result of the reception quality is input to the frequency quality storage 318 and stored together with the carrier frequency information from the carrier frequency selector 316. In this way, the transmission quality for each carrier frequency is stored in the frequency quality storage unit 318.

Next, when the downlink signal is transmitted from the base station 300, the signal input from the outside is transmitted to the signal distributor 32.
Input to 0. In the signal allocator 320, the carrier frequency selector 3 notified from the frequency quality memory 318.
The transmission quality of the carrier frequency selected by 16 is referred to. If the transmission quality is good, the signal with the required high line quality among the input signals is selected, and if the transmission quality is poor, the input signal Among them, the signal with the required low channel quality is output to the modulator 313.

The signal output from the signal distributor 320 is modulated by the modulator 313. The modulated signal becomes a transmission signal having the carrier frequency obtained by the carrier frequency selector 316 in the transmitter 314 as a carrier. As a result, a signal with a higher required channel quality is transmitted at a carrier frequency with a better transmission quality.

Further, unlike the conventional frequency diversity, the same data is not simultaneously transmitted using a plurality of frequencies, so that the frequency utilization efficiency does not deteriorate. Transmitter 3
The output of 14 is connected to the switch 303 and transmitted from the corresponding antenna 301.

On the other hand, in the mobile station 400, the downlink signal is received by the antenna 401 and output to the switch 402. The switch 402 switches the connection destination during transmission and reception, as in the case of the switch 303 in the base station. The reception signal is input to the receiver 403 when the downlink signal is received.

At the same time, the carrier frequency selector 407 outputs the carrier frequency of the signal to be received to the receiver 403 similarly to the carrier frequency selector 316 in the base station.
The receiver 403 outputs to the demodulator 405 the signal of the carrier frequency notified from the carrier frequency selector 407 among the received signals. The signal output from the receiver 403 is demodulated by the demodulator 405 and output.

A signal input from the outside at the time of transmitting an upstream signal from the mobile station is modulated by the modulator 406. Further, the carrier frequency selector 407 notifies the transmitter 404 of the carrier frequency to be used at the time of transmission. Then, the modulated signal modulated by the modulator 406 is transmitted to the transmitter 4
04, it becomes a transmission signal and is transmitted from the antenna 401 via the switch 402.

In the above-mentioned example, the quality of the signal is judged based on the strength of the received signal. However, as another measure of the quality of the received signal, the signal-to-noise ratio (S /
N), the bit error rate, etc. may be used alone or in combination.

FIG. 3 is a diagram showing a second example of the embodiment of the present invention, in which the base station determines the transmission quality as the S / N of the received signal.
And the bit error rate, and informs the mobile station of the correspondence between the detected transmission quality of the received signal and the carrier frequency, and the mobile station selects the carrier frequency for transmitting the signal based on this. The structure in the case is shown.

Regarding the operations of the base station and the mobile station in this example, differences from the case of the first example described above will be described below. That is, in the first example, the reception intensity is adopted as the index of the quality of the received signal, but in this example, the received signal quality detector 319 detects the S / N of the received signal. (This can also be made to detect the bit error rate of the received signal.) Then, the result is stored in the frequency quality storage 318 in correspondence with the carrier frequency.

This frequency quality information is incorporated into the header of the transmission signal by the frequency quality information editor 321.
Transmitted by transmitter 314 via antenna 301. In the mobile station 400, the frequency information recognizer 408 knows the carrier frequency of good transmission quality from the header of the received signal, and the transmission quality for each carrier frequency is stored in the frequency quality storage 409.

On the other hand, the signal distributor 410 discriminates whether the input signal to be transmitted is a signal which requires a high transmission quality or a signal which does not require such a high transmission quality. The carrier frequency selector 407 is notified to use the carrier frequency that meets the conditions.
The carrier frequency selector 407 selects a carrier frequency for transmitting a signal based on this notification. The operation other than the above operation is the same as the case of the first example.

FIG. 4 is a block diagram showing a third example of the embodiment of the present invention. Here, an example is shown in which base station 300 uses two antennas to perform space diversity. FIG. 2 shows an example of a signal format when bidirectional communication is performed by the TDD method using this device. As shown in the figure, the base station and the mobile station perform bidirectional communication by alternately transmitting and receiving upstream signals and downstream signals in time.

In FIG. 4, the antenna 3 of the base station 300
The upstream signals received by 01 and 302 are input to the corresponding switches 303 and 304, respectively. The switches 303 and 304 are switches that switch the connection destination of the antenna during reception and during transmission in TDD communication. At the time of receiving the upstream signal, the received signals are the receivers 305 and 3 corresponding to the switches 303 and 304, respectively.
The signals of the carriers, which are input to 06 and notified by the carrier frequency selector 316, are received by the receivers 305 and 306, respectively.

As shown in FIG. 2, the carrier frequency selector 316 selects a carrier frequency to be used at the time of reception and transmission and outputs the information.
At the same time, the carrier frequency information of the carrier frequency selector 316 is input to the frequency quality memory 318. Further, at the time of transmission, the carrier frequency selector 316 inputs the carrier frequency information used at the time of transmission to the signal distributor 315 and the transmitter 314.

The received signals output from the receivers 305 and 306 are received signal strength detectors 30 corresponding to the received signals.
9 and 310, and demodulators 307 and 308
Are also input respectively. Received signal strength detector 309,
310 detects the signal strength of each received signal output from the receivers 305 and 306. Then, the reception signal strengths detected by the reception signal strength detectors 309 and 310, that is, the detection results of the reception qualities are input to the comparator 311.

The comparator 311 compares the signal strengths detected by the respective received signal strength detectors, and sets the switch 312 so that the demodulated signal obtained from the demodulator corresponding to the antenna having a high signal strength is output. . That is, the base station 3
The signal received by the antenna with the better reception quality is output to the output terminal of 00. Furthermore, the comparator 3
The output of 11 is input to the frequency quality storage unit 318 and stored together with the carrier frequency information from the carrier frequency selector 316.

In this way, the frequency quality storage unit 318 stores each transmission quality for each carrier frequency. Next, when transmitting the downlink signal from the base station 300, the signal input from the outside is input to the signal divider 317,
It is classified into a signal with a high required channel quality and a signal with a low required channel quality. The signal divided by the signal divider 317 is input to the signal distributor 320.

In the signal distributor 320, the carrier frequency selector 316 notified by the frequency quality storage 318.
Refer to the transmission quality of the carrier frequency selected by
If the transmission quality is good, a signal having a high required line quality among the divided signals is used, and if it is bad, a signal having a low required line quality is used among the divided signals.
Output to 3.

The signal output from the signal distributor 320 is modulated by the modulator 313. The modulated signal becomes a transmission signal having the carrier frequency obtained by the carrier frequency selector 316 in the transmitter 314 as a carrier. As a result, a signal with a higher required channel quality is transmitted at a carrier frequency with a better transmission quality.

Further, unlike the conventional frequency diversity, the same data is not simultaneously transmitted using a plurality of frequencies, so that the frequency utilization efficiency does not deteriorate. Transmitter 3
The output of 14 is connected by the switch 315 to the switch 303 or 304 side corresponding to the antenna with the highest signal strength among the signals from the two antennas received at the transmission carrier frequency obtained by the carrier frequency selector 316. And transmitted from the corresponding antenna 301 or 302.

On the other hand, in the mobile station 400, the downlink signal is received by the antenna 401 and output to the switch 402. The switch 402 is a switch 303, 30 in the base station.
Similar to 4, the connection destination is switched during transmission / reception. The reception signal is input to the receiver 403 when the downlink signal is received.
At the same time, the carrier frequency selector 407 outputs the carrier frequency of the signal to be received to the receiver 403 similarly to the carrier frequency selector 316 in the base station.

The receiver 403 outputs to the demodulator 405 the signal of the carrier frequency notified from the carrier frequency selector 407 among the received signals. The signal output from the receiver 403 is demodulated by the demodulator 405 and output. A signal input from the outside at the time of transmitting the uplink signal from the mobile station is modulated by the modulator 406. Further, the carrier frequency selector 407 notifies the transmitter 404 of the carrier frequency to be used at the time of transmission. Thereafter, the modulated signal modulated by the modulator 406 becomes a transmission signal by the transmitter 404, and is transmitted from the antenna 401 via the switch 402.

FIG. 5 is a diagram showing a fourth example of the embodiment of the present invention, in which the base station 300 adopts a structure for performing space diversity using two antennas and the transmission quality is determined by the received signal. 2 shows a configuration in which the S / N and the bit error rate are used for the determination.

In this configuration, the received signal strength detectors 309 and 310 in FIG. 4 are replaced by the received quality detectors 319 and 322.
To the demodulators 307 and 308, respectively.
I am trying to get from.

The reception quality detectors 319 and 322 obtain the S / N or bit error rate for each carrier frequency from the demodulated signals of the respective systems, detect the transmission quality from this, and store this in the frequency quality storage. It is stored in the container 318. The other operations are exactly the same as those described with reference to FIG.

According to each of the above-described embodiments, the higher the channel quality required by the base station, the more the data is allocated to the frequency with the better transmission quality and transmitted. It is possible to receive data from the base station with quality. Here, FIG. 6 shows a code error rate characteristic by computer simulation in the example of the embodiment shown in FIG. In the figure, the vertical axis represents the code error rate, and the horizontal axis represents the average Eb / No (the ratio of the signal power per bit to the noise power density). The signal format used is that shown in FIG.

In this simulation, the transmission rate is 3
84 kbps, modulation / demodulation system is π / 4 shift QPSK-delay detection system, communication system is 8 ch with frame period of 10 ms.
For TDMA-TDD and fading, 2-wave equal level Rayleigh fading with a fading frequency of 15 Hz and a delay time difference of 500 ns was assumed.

Further, there is no correlation between the two frequencies used. From FIG. 6, it can be seen that the floor of the code error rate is reduced to about 1/20 for the data with high required channel quality by this embodiment.
It can also be seen that the required code error rate of data with low channel quality is a little less than twice the code error rate when this method is not used.

In each of the above embodiments, the case where the present invention is applied to the communication between the base station and the mobile station in the mobile communication has been described. However, the present invention describes the communication between the fixed stations. It goes without saying that it can also be applied to.

[0057]

As described above, according to the present invention, for a plurality of signals having different required channel qualities,
Since the carrier frequency is used in a time-divisional manner and the higher the required channel quality signal, the better the transmission quality frequency is allocated and transmitted, so that the low power consumption device does not deteriorate the frequency utilization efficiency and the good information transmission quality. There is an advantage that can be obtained.

[Brief description of drawings]

FIG. 1 is a diagram showing a first example of an embodiment of the present invention.

FIG. 2 is a diagram showing an example of a signal format used in the present invention.

FIG. 3 is a diagram showing a second example of the exemplary embodiment of the present invention.

FIG. 4 is a diagram showing a third example of an exemplary embodiment of the present invention.

FIG. 5 is a diagram showing a fourth example of an exemplary embodiment of the present invention.

FIG. 6 is a diagram showing an example of characteristics of a code error rate according to the embodiment of the present invention.

FIG. 7 is a diagram showing an example of a configuration of a mobile communication device using a conventional TDD system.

FIG. 8 is a diagram showing an example of a signal format.

[Explanation of symbols]

300 base station (first transceiver) 301, 302, 401 antenna 303, 304, 312, 315, 102 switch 305, 306, 403 receiver 307, 308, 405 demodulator 309, 310 received signal strength detector 311 comparison Device 313,406 Modulator 314,404 Transmitter 316,407 Carrier frequency selector (carrier frequency designating means) 317 Signal divider (dividing means) 318,409 Frequency quality memory 319,322 Received signal quality detector 320,410 Signal distributor (setting means) 321 Frequency quality information editor 400 Mobile station 408 Frequency quality information recognizer

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Shuji Kubota 3-19-2 Nishishinjuku, Shinjuku-ku, Tokyo Nippon Telegraph and Telephone Corporation

Claims (4)

[Claims] 1. A diversity communication apparatus comprising a first transceiver and a second transceiver for transmitting and receiving the first transceiver, wherein the first transceiver has a plurality of different second transceivers. Receiving means for receiving each of a plurality of signals transmitted by using the carrier frequency of the above in a time division manner, measuring the reception quality of each received signal received by the receiving means, and measuring the carrier quality from the measurement result. A signal transmission quality detecting means for detecting the signal transmission quality for each frequency, and transmission carrier frequencies of a plurality of signals to be transmitted according to the detection result of the signal transmission quality of each carrier frequency obtained by the signal transmission quality detecting means. A diversity communication characterized by comprising setting means for setting each signal and transmitting means for transmitting each of the signals at each transmission carrier frequency set by the setting means. Apparatus. 2. The first transmitter / receiver is provided with a detection result of each signal transmission quality at each carrier frequency obtained by the signal transmission quality detecting means, or a value indicating the quality of the relative transmission quality of each frequency. Transmission quality recognition that includes detection result notifying means for notifying the second transceiver, and recognizes the detection result of the signal transmission quality of each carrier frequency notified from the first transceiver to the second transceiver. Means, setting means for setting, for each signal, transmission carrier frequencies of a plurality of signals to be transmitted according to the detection result of the signal transmission quality of each carrier frequency recognized by the signal transmission quality recognizing means, and the setting means 2. The diversity communication device according to claim 1, further comprising: a transmitting unit that transmits each signal at each transmission carrier frequency of each signal set by the above. 3. A dividing unit that divides a plurality of transmission signals input to the first transceiver into a plurality of signals according to the required high transmission quality, and a setting of the first transceiver. In the means, a carrier frequency having a better signal transmission quality of the carrier frequency obtained by the signal transmission quality detecting means is set for a signal requiring higher transmission quality among the plurality of types of transmission signals divided by the dividing means. 3. The diversity communication device according to claim 1, further comprising carrier frequency designating means for designating as described above. 4. A dividing unit for dividing a plurality of transmission signals input to the second transceiver into a plurality of signal groups according to the required high transmission quality, and a dividing unit for the second transceiver. In the setting means, a carrier frequency having a better signal transmission quality of the carrier frequency recognized by the signal transmission quality recognizing means is set for a signal requiring higher transmission quality among a plurality of types of transmission signals divided by the dividing means. 4. The diversity communication device according to claim 2 or 3, further comprising carrier frequency designating means for designating to perform.