JP3201598B2 - Multi-way time division multiplex wireless communication system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-directional time-division multiplexing radio communication system in which, when a bit error occurs in a transmission signal due to an interference wave in a radio section, a station that first receives the interference wave The present invention relates to a multi-directional time-division multiplexing wireless communication system which can reduce the influence of the interference wave to other stations and realize stable information transmission.

[0002]

2. Description of the Related Art Generally, as shown in FIG. 4, a multi-way time division multiplex radio communication system has one base station, and a plurality of relay stations and terminal stations facing the base station. 1: N time division multiplex communication is performed. In the downlink signal transmission from the base station to the relay station or terminal station, or from the relay station to the terminal station, that is, in the downstream signal transmission from the upper station to the lower station, the direction from which the data is transmitted from the upper station is determined. A directional antenna is used as an antenna for receiving a signal from an upper station in a station.

On the other hand, in the upstream signal transmission from the terminal station to the relay station or the base station or from the relay station to the base station, that is, from the lower station to the upper station, the lower stations uniformly scattered around the upper station. , A non-directional antenna is used as an antenna for receiving a signal from a lower station in an upper station.
Therefore, in uplink signal transmission, unnecessary interference waves are easily received at the same time, and are easily affected by interference.

[0004] Next, a case where an interference wave is transmitted to the next higher station will be described with reference to FIG. FIG. 4 is an example of a conventional multi-directional time-division multiplex wireless communication system. The terminal station 1 transmits a signal to the relay station 2 using the time slot TS1, and the terminal station 4 transmits a signal to the relay station 2 using the time slot TS3.
Signal transmission. Relay station 2 has time slot TS1
And the signal is transmitted to the base station 3 using the TS3.

[0005] Similarly, the terminal station 5 has a time slot TS.
2, and the terminal station 6 transmits a signal to the relay station 7 using the time slot TS4. The relay station 7 uses the time slots TS2 and TS4 to
Signal transmission. For example, an interference wave is generated in the allocation area of the relay station 2, the relay station 2 erroneously recognizes this as a signal from a lower terminal station, and relays the interference wave signal to the base station 3 using the time slot TS4. Suppose that it was transmitted.

[0006] That is, the relay station 2 sets the time slot TS1
Signal transmission to the base station 3 using the TS3 and the TS3 and the TS4, and the uplink signal transmission between the terminal station 6, the relay station 7 and the base station 3 performed using the time slot TS4 in a completely different area. , The time slot TS4 collides in space, which hinders upstream signal transmission between the terminal station 6, the relay station 7, and the base station 3. That is, signal transmission in an area completely different from the area where the interference wave is generated is affected. Normally, the influence of the interference wave affects not a single time slot but a large number of time slots, thereby occupying the time slot, thereby increasing the damage to the entire communication system.

Next, a configuration in which information data is transmitted from the transmission part of the terminal station 1 to the reception part of the relay station 2 in the conventional multi-way time division multiplex radio communication system will be described with reference to FIG. First, the configuration of the terminal 1 will be described.
The baseband signal processing circuit 13 performs signal processing such as multiplexing of main signal data and control data into radio frames.

The signal processed by the baseband signal processing circuit 13 is modulated by a modulation circuit 16 using a modulation method such as QPSK. The modulated signal is amplified by the transmission circuit 17 and transmitted by the antenna 18 to the relay station 2 by radio waves.

Next, the configuration of the relay station 2 will be described.
First, the signal transmitted from the terminal station 1 is received by the antenna 19. The signal received by the antenna 19 is amplified by the receiving circuit 20, converted from the RF frequency to the IF frequency, demodulated by the demodulation circuit 21, and becomes a digital signal of a logical level "1" or "0". Further, the reception level detection circuit 24 detects the input level of the reception signal and converts it to a voltage level SIG4 corresponding to the detected input level.

In a reference voltage generating circuit 27, a reference voltage S corresponding to a preset relay threshold level is set.
Generate IG5. Note that the relay threshold level is a level set so that when the reception input level is higher than the relay threshold level, the signal is relayed to an upper station, and when the reception input level is lower, the relay is not performed.

The voltage level SIG4 and the reference voltage SIG5 are applied to a comparison circuit 28. The comparison circuit 28 compares a voltage level SIG4 corresponding to the reception input level with a reference voltage level SIG5 corresponding to the relay threshold level. For example, when the voltage level SIG4 corresponding to the reception input level is higher than the reference voltage level SIG5 corresponding to the relay threshold level, the output logic level is set to “1”, and when it is lower, the output logic level is set to “0”.

[0012] The baseband signal processing circuit 2 3, when the output logic level of the comparison circuit 28 is "1", performs the relay signal processing to the main signal transmitted from the terminal station 1, to the next higher station It is transmitted, but is not transmitted when the output logic level of the comparison circuit 28 is “0”. For convenience of explanation, FIG.
In FIG. 2, circuits and signal lines which are not particularly important are omitted.

Next, the operation of a conventional multidirectional time division multiplex radio communication system when a signal is affected by an interference wave will be described with reference to FIG. FIG. 6 shows how the voltage level SIG4 and the reference voltage level SIG5 are compared by the comparison circuit 28.

As shown in FIG. 6, it is assumed that a signal receives an interference wave in a radio section and the voltage level SIG4 rises. Since the level of the reference voltage level SIG5 is predetermined and fixed, the voltage level SIG4 is changed to the reference voltage level SI in the rising portion of the voltage level SIG4 due to the interference wave.
Since it is larger than G5, the comparison circuit 28 outputs "1" as an output logic level, and the baseband signal processing circuit 13 performs relay signal processing on the interference wave signal and transmits it to the upper station.

[0015]

As described above, in a conventional multi-way time division multiplexing radio communication system, if an interference wave is received at a reception level higher than a predetermined relay threshold level, the receiving station is rejected. Is erroneously recognized as a main signal from a lower station and performs relay signal processing to transmit an interference wave signal to an upper station, which causes a problem in the entire communication system.

In Japanese Patent Application Laid-Open No. 04-267647, inter-symbol interference that exceeds the equalizing capability of an equalizer that compensates for frequency selection characteristic fading included in a received signal occurs when a criterion for determining diversity branch selection is used. In case,
It is disclosed that a branch having little residual intersymbol interference and a branch having a high S / N ratio are adaptively selected from one of the branches when intersymbol interference equal to or less than the equalization capability of the equalizer occurs. However, in the case of this publication,
It is not a clue to solving the above problems.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problem. An interference wave generated in a radio section is removed by a station which first receives the signal, and other stations are affected by the interference wave. It is an object of the present invention to provide a multi-way time division multiplex wireless communication system capable of constructing a stable wireless communication system.

[0018]

In order to achieve the above object, a multidirectional time division multiplex radio communication system according to the present invention comprises:
A station that modulates and transmits a multiplexed signal obtained by multiplexing a test pattern signal with a baseband signal and a control signal in a predetermined time slot of a radio frame, and receives and demodulates a transmission signal transmitted from the station. Based on the bit error information of the test pattern signal obtained by separating the baseband signal from the demodulated signal and the received signal level, it is determined whether or not the received signal is affected by an interference wave. A relay circuit for stopping transmission to an upper station, the relay station receiving a transmission signal transmitted from the station, converting the RF frequency to an IF frequency, and outputting the converted signal; A reception level detection circuit for detecting an input signal level of the received signal, generating a voltage level corresponding to the input signal level, and demodulating an output signal of the reception circuit; A demodulation circuit that outputs a digital signal of a logical level “1” or “0”; a separation circuit that separates a digital signal modulated by the demodulation circuit into a main signal, control data, and a test pattern signal; A pattern detector that compares the test pattern of the separated tester pattern signal with a predetermined test pattern to detect the presence or absence of a bit error in the test pattern and outputs bit error information, and an output from the reception level detection circuit. Based on the obtained voltage level and the bit error information information output from the pattern detector,
If a bit error is detected in the test pattern signal even though the input level of the reception signal is sufficient, it is determined that the reception signal has been affected by the interference wave, and the reference voltage level is set to the input level of the interference wave. And a reference voltage level control means for controlling the voltage to be lower than a voltage level corresponding to a reception input level from the station, and a reference voltage level obtained by the reference voltage level control means. Relay signal processing means for performing relay signal processing on the main signal and the control data transmitted from the station according to the magnitude relationship with the voltage level to determine whether or not transmission to the next higher station is possible; It is characterized by.

According to the multi-way time division multiplexing radio communication system of the present invention, a station modulates a multiplexed signal obtained by multiplexing a test pattern signal with a baseband signal and a control signal in a predetermined time slot of a radio frame. When the transmission signal is transmitted by radio wave to the relay station, the relay station receives the transmission signal, separates the test pattern signal from the baseband signal after demodulating the received signal, and detects the bit error of the separated test pattern signal. To detect. Then, it is determined whether or not the received signal is affected by the interference wave based on the received signal level and the bit error information of the test pattern signal in which the bit error is detected. If the received signal is affected by the interference wave, transmission to the next higher station is not performed. That is, the receiving circuit of the relay station receives the transmission signal transmitted from the station, converts the RF frequency to the IF frequency, and outputs the converted signal. The reception level detection circuit detects an input signal level of a reception signal received by the reception circuit, and generates a voltage level corresponding to the input signal level. The demodulation circuit demodulates an output signal of the reception circuit and outputs a digital signal of a logical level “1” or “0”. The separation circuit separates the digital signal modulated by the demodulation circuit into a main signal, control data, and a test pattern signal. The pattern detector compares the test pattern of the tester pattern signal separated by the separation circuit with a predetermined test pattern, detects the presence or absence of a bit error in the test pattern, and outputs bit error information. The reference voltage level control means, based on the voltage level output from the reception level detection circuit and the bit error information information output from the pattern detector, detects a bit error in the test pattern signal even though the input level of the reception signal is sufficient. Is detected, it is determined that the received signal has been affected by the interference wave, and the reference voltage level is higher than the voltage level corresponding to the input level of the interference wave and lower than the voltage level corresponding to the reception input level from the station. Control so that The relay signal processing means performs the relay signal processing on the main signal and the control data transmitted from the station according to the magnitude relationship between the reference voltage level and the voltage level obtained by the reference voltage level control means, and proceeds to the next higher station. It is determined whether or not transmission is possible.

Therefore, according to the present invention, it is possible to construct a stable wireless communication system in which an interference wave generated in a wireless section is removed by a station that first receives the signal, and the other stations are not affected by the interference wave.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of a multi-way time division multiplex radio communication system according to the present invention will be described with reference to the drawings. First, the configuration of the embodiment according to the present invention will be described in detail. FIG. 1 shows a configuration in which a signal is transmitted from a transmitting part of a terminal station 1 to a receiving part of a relay station 2 in the multi-way time division multiplexing wireless communication system of the present invention. First, the configuration of the terminal 1 will be described. The baseband signal processing circuit 13 performs signal processing such as multiplexing of main signal data and control data on a radio frame, and outputs an output signal SIG1. This output signal SIG1 is input to the multiplexing circuit 14.

The pattern generator 15 generates a test pattern signal SIG2 such as a predetermined PN (Pseudo Noise) pattern. The test pattern signal SIG2 is input to the multiplex circuit 14. The multiplexing circuit 14 allocates the test pattern signal SIG2 from the pattern generator 15 to a predetermined time slot on the radio frame as shown in FIG. 2, and multiplexes the SIG2 with the output signal SIG1 of the baseband signal processing circuit 13. The multiplexed multiplexed signal SIG3 is subjected to QPS
It is modulated by a modulation method such as K. The modulated signal is amplified by the transmission circuit 17 and transmitted to the relay station 2 as a radio wave in a wireless section by the antenna 18.

Next, the configuration of the relay station 2 will be described.
First, the transmission signal transmitted from the terminal station 1 is received by the antenna 19. The received signal is amplified by the receiving circuit 20, and R
The signal is converted from the F frequency to the IF frequency, demodulated by the demodulation circuit 21, and becomes a digital signal having a logical level “1” or “0”. The separation circuit 22 separates the main signal data, the control data, and the test pattern signal SIG2.

The pattern detector 29 detects a bit error by comparing a predetermined test pattern with a test pattern of a test pattern signal actually received and separated by the separation circuit 12. Further, the reception level detection circuit 24 detects the input level of the reception signal and converts it to a voltage level SIG4 corresponding to the input level of the reception signal. A / D (analog / digital)
The conversion circuit 25 converts the voltage level SIG4 from an analog signal to a digital signal.

The reference voltage control circuit 26 controls the reference voltage level corresponding to the relay threshold level based on the received input level information from the A / D conversion circuit 25 and the bit error information from the pattern detector 29. When a bit error is observed in the test pattern signal even though the input level of the received signal is sufficient, the reference voltage control circuit 26 determines that the radio signal has been affected by the interference wave, and The voltage generation circuit 27 is controlled to increase the reference voltage level SIG5. Note that the relay threshold level is a level set so that when the reception input level is higher than the relay threshold level, the signal is relayed to the upper station, and when the received input level is lower, the signal is not relayed to the upper station. is there.

In the reference voltage generation circuit 27, the reference voltage level SIG is controlled according to the control from the reference voltage control circuit 26.
5 is generated. The A / D converter 25, the reference voltage control circuit 26, and the reference voltage generation circuit 27 constitute reference voltage level control means. The comparison circuit 28 includes a voltage level SIG4 corresponding to the reception input level and a reference voltage level SI corresponding to the relay threshold level.
Compare with G5. In this case, for example, when the voltage level SIG4 corresponding to the reception input level is higher than the reference voltage level SIG5 corresponding to the relay threshold level, the output logic level is set to "1", and when it is lower, the output logic level is set to "0". I do.

When the output logic level of the comparison circuit 28 is "1", the baseband signal processing circuit 23 performs relay signal processing on the main signal sent from the terminal station 1 and transmits the signal to the next higher station. However, when the output logic level of the comparison circuit 28 is “0”, no transmission is performed. The baseband signal processing circuit 23 and the comparison circuit 28 constitute a relay signal processing unit. For convenience of explanation, circuits and signal lines which are not particularly important in FIG. 1 are omitted.

Next, the operation of the embodiment configured as described above will be described first, starting from the operation of the terminal station 1. The baseband signal processing circuit 13 performs signal processing such as multiplexing of main signal data and control data on a radio frame, outputs an output signal SIG1, and outputs the output signal SIG1.
4 is output.

The pattern generator 5 generates a test pattern signal SIG2 such as a predetermined PN pattern.
Occurs. The multiplexing circuit 4 multiplexes the output signal SIG1 from the baseband signal processing circuit 13 with a test pattern signal SIG2 from the pattern generator 15 in a predetermined time slot on the radio frame, and outputs a multiplexed signal SIG3. FIG. 2 shows how the output signals SIG1 and SIG2 from the baseband signal processing circuit 13 are time-division multiplexed.

A multiplexing circuit 4 multiplexes the test pattern signal SIG2 shown in FIG. 2B with the output signal SIG1 from the baseband signal processing circuit 13 shown in FIG. The signal SIG3 is QP
It is modulated by a modulation method such as SK. The modulated signal is amplified by the transmission circuit 17, the transmission signal is radiated as a radio wave in a wireless section by the antenna 18, and transmitted to the relay station 2.

Next, the operation of the relay station 2 will be described. The transmission signal transmitted from the terminal station 1 is received by the antenna 19. The received transmission signal is input as a reception signal in a reception circuit 20, is amplified there, is converted from an RF frequency to an IF frequency, is demodulated in a demodulation circuit 21, and has a digital level of "1" or "0". Signal. This digital signal is input to the separation circuit 22. Separation circuit 2
In step 2, the main signal data, the control data, and the test pattern signal are separated from the digital signal data demodulated by the demodulation circuit 21.

The operation of the separation circuit 22 is performed by the multiplexing circuit 14.
The operation is exactly the opposite of The test pattern signal separated from the main signal data and the control data by the separation circuit 22 is compared with a predetermined test pattern in the pattern detector 29, and a bit error is detected. Further, the reception level detection circuit 24 detects the input level of the reception signal output from the reception circuit 20, and converts the input level to the corresponding voltage level SIG4.

The voltage level SIG4 is supplied to the A / D conversion circuit 25.
Is converted from an analog signal to a digital signal. This digital signal is input to the reference voltage control circuit 26. The reference voltage control circuit 26 controls the reference voltage level SIG5 corresponding to the relay threshold level based on the reception input level information from the A / D conversion circuit 25 and the bit error information of the test pattern signal from the pattern detector 29. .

The control of the reference voltage level SIG5 by the reference voltage control circuit 26 means that a bit error is detected in the test pattern from the received input level information and the bit error information of the test pattern even though the received input level is sufficient. If it is determined that the received signal is affected by the interference wave, the reference voltage level SIG5
Is to control the reference voltage generation circuit 27 so as to be higher than the voltage level corresponding to the input level of the interference wave and lower than the voltage level corresponding to the reception input level of the signal from the terminal station 1.

The reference voltage generation circuit 27 generates a reference voltage level SIG5 according to the control from the reference voltage control circuit 26. The reference voltage level SIG5 generated from the reference voltage control circuit 26 is input to the comparison circuit 28. The voltage level SIG4 output from the reception level detection circuit 24 is also input to the comparison circuit 28.

Therefore, the comparison circuit 28 compares the voltage level SIG4 corresponding to the reception input level with the reference voltage level SIG5 corresponding to the relay threshold level. The comparison circuit 28 sends the comparison result of the magnitude relationship between the voltage level SIG4 and the reference voltage level SIG5 to the baseband signal processing circuit 23.

As a result of the comparison, for example, when the voltage level SIG4 corresponding to the reception input level is higher than the reference voltage level SIG5 corresponding to the relay threshold level, the output logic level is set to "1", and when it is lower, it is set to "0".
And When the output logic level of the comparison circuit 28 is “1”, the baseband signal processing circuit 23 performs relay signal processing on the main signal and the control signal sent from the terminal station 1, and performs the next higher-level station operation. , But is not transmitted if it is “0”.

Next, the operation when the signal is affected by the interference wave will be specifically described with reference to FIG. FIG.
Shows a state in which the comparison circuit 28 compares the voltage level SIG4 with the reference voltage level SIG5. As shown in FIG. 3, it is assumed that the signal is affected by the interference wave in the wireless section, and the voltage level SIG4 is increased.

At this time, it is determined that the reference voltage control circuit 26 is affected by the interference wave, and the reference voltage level SIG5
Of the voltage level SIG4 due to the interference wave, the voltage level SIG4 does not become higher than the reference voltage level SIG5, and the comparison circuit 28 outputs "0" as the output logic level. Is output, the baseband signal processing circuit 2
In No. 3, the relay signal processing is performed on the interference wave and the signal is not transmitted to the upper station.

As described above, in the embodiment of the present invention, the test pattern signal is multiplexed on a predetermined portion of the radio frame on the transmitting side, and the bit error information of the test pattern signal received on the receiving side is multiplexed. From the received input level information, it is determined whether or not it is an interference wave, and if it is determined that it is an interference wave, it is not transmitted to the next upper station, so the interference wave is removed by the station that first received the interference wave Since the interference wave does not affect other stations, communication interference due to the interference wave can be minimized.

Therefore, in a multi-directional time division multiplexing radio communication system, an interference wave generated in a radio section is removed by a station that first receives the signal, and the other stations are not affected by the interference wave. You can build a system.

The present invention is not limited to the transmitting part of the terminal station 1 and the receiving part of the relay station 2 as in the application example in the above embodiment, but can be applied to other cases. It is. For example, when information is transmitted from a lower relay station to a higher relay station, the present invention can be applied to a transmitter of a lower relay station and a receiver of a higher relay station. The same effect can be obtained.

[0043]

As described above, according to the present invention, a test pattern signal is multiplexed on a predetermined time slot in a radio frame of main signal data and control data on the transmitting side.
The receiver determines whether or not the signal is an interference wave based on the bit error information of the test pattern signal received and the voltage level information of the received signal. In the case of the interference wave, the transmission to the upper station is stopped. The station that first receives the interference wave can remove the interference wave. Therefore, it is possible to prevent the influence of the interference wave on other stations from occurring, and it is possible to minimize communication interference caused by the interference wave.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of a multidirectional time-division multiplex wireless communication system according to the present invention.

FIG. 2 is a time chart showing how an output signal of a baseband signal processing circuit and a test pattern signal are multiplexed in the embodiment of the multidirectional time division multiplexing wireless communication system according to the present invention.

FIG. 3 is an explanatory diagram of a comparison state of a reference voltage level and a voltage level corresponding to a received signal level by a comparison circuit in the embodiment of the multi-way time division multiplexing wireless communication system according to the present invention.

FIG. 4 is an explanatory diagram showing a state in which an interference wave in a conventional multi-directional time-division multiplexing wireless communication system is transmitted to a next higher station.

FIG. 5 is a block diagram showing a configuration of a conventional multi-directional time division multiplex wireless communication system.

FIG. 6 is an explanatory diagram of a comparison state of a reference voltage level and a voltage level corresponding to a received signal level by a comparison circuit in a conventional multidirectional time division multiplexing wireless communication system.

[Explanation of symbols]

1, terminal stations, 2, relay stations, 13, 23, baseband signal processing circuits, 14, multiplex circuits, 15, pattern generators, 16, modulation circuits, 17, transmission circuits,
18, 19 ... antenna, 20 ... reception circuit, 21 ...
Demodulation circuit, 22 separation circuit, 24 reception level detection circuit, 25 A / D conversion circuit, 26 reference voltage control circuit, 27 reference voltage generation circuit, 28 comparison circuit,
29 ... Pattern detector.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) H04J 3/00-3/26 H04L 5/22-5/26 H04B 7/14-7/26 H04L 1 / 00

Claims (8)

(57) [Claims] 1. A station for modulating a multiplexed signal obtained by multiplexing a baseband signal and a control signal with a test pattern signal in a predetermined time slot of a radio frame and transmitting the modulated signal, and a transmitting signal transmitted from the station. Based on the bit error information of the test pattern signal obtained by separating the baseband signal from the demodulated signal received and demodulated and the level of the received signal, the presence or absence of the influence of the interference wave of the received signal is determined. effect and a relay station to stop transmission to the host station when there is, the relay station receives the transmission signal transmitted from the station
Receiver that converts RF frequency to IF frequency and outputs
Signal level of the received signal received by the receiving circuit.
Voltage level corresponding to this input signal level.
And the output of the above-mentioned receiving circuit.
The input signal is demodulated to a logic level "1" or "0".
Digital signal and demodulation circuit
Main signal, control data and test from the digital signal
A separation circuit for separating the signal into pattern signals,
The test pattern of the separated tester pattern signal and the
Compare the test pattern with the determined test pattern.
Detected bit errors and output bit error information.
Pattern detector to be applied and the above-mentioned reception level detection circuit
The voltage level output from the
Based on the bit error information output from the
The above test is performed even though the input level of the received signal is sufficient.
When a bit error is detected in the
Signal is affected by the interference wave and the reference voltage level
Is larger than the voltage level corresponding to the input level of the interference wave.
Voltage that corresponds to the reception input level from the above station
Reference voltage level control to control to be lower than level
Control means and the reference voltage level control means
Depending on the magnitude relationship between the reference voltage level and the above voltage level
The main signal transmitted from the station and the control data
Performs relay signal processing and determines whether transmission to the next higher station is possible
Multidirectional time division multiplex radio communication system Ru and a relay signal processing means, characterized by. 2. A baseband signal processing circuit for performing signal processing of a multiplex signal of a main signal data and control data in a radio frame, a pattern generator for generating a test pattern signal of a predetermined pattern, A multiplexing circuit that allocates the test pattern signal to a predetermined time slot on a radio frame and multiplexes the output signal of the baseband signal processing circuit; a modulation circuit that modulates the signal multiplexed by the multiplexing circuit; 2. The multi-way time division multiplex wireless communication system according to claim 1, further comprising a transmission circuit for amplifying an output signal of the modulation circuit and transmitting the amplified signal as a radio wave. 3. The multi-way time division multiplex wireless communication system according to claim 2, wherein said modulation circuit modulates a signal multiplexed by said multiplexing circuit according to a QPSK modulation method. 4. The reference voltage level control means includes a reference voltage generation circuit for generating the reference voltage level, an analog / digital conversion circuit for converting the voltage level output from the reception level detection circuit into a digital signal. ,
A voltage level converted into a digital signal by the analog / digital conversion circuit and bit error information output from the pattern detector are input, and a bit is input to the test pattern signal even though the input level of the received signal is sufficient. If an error is detected, it is determined that the received signal has been affected by the interference wave, and the reference voltage level is higher than the voltage level corresponding to the input level of the interference wave, and corresponds to the reception input level from the station. multidirectional time division multiplex radio communication system according to claim 1, characterized in that it comprises a reference voltage control circuit for controlling the reference voltage generating circuit to be less than the voltage level. 5. The relay signal processing means compares the voltage level output from the reception level detection circuit with the reference voltage level output from the reference voltage generation circuit, and compares the voltage level with the reference level. A comparison circuit that outputs a logic level corresponding to the magnitude relationship with the voltage level; and a main signal and control data transmitted from the station according to the logic level output from the comparison circuit to the next higher-level station. claim 1 or 4 multidirectional time division multiplex radio communication system, wherein further comprising a baseband signal processing circuit for determining the propriety. 6. The comparison circuit outputs a logic level “1” when the voltage level is higher than the reference voltage level, and outputs a logic level when the voltage level is lower than the reference voltage level. 6. The multi-way time division multiplexing wireless communication system according to claim 5 , wherein a level "0" is output. 7. The baseband signal processing circuit performs a relay signal process on the main signal and the control data when the comparison circuit outputs a logical level “1” and transmits the result to the next higher-level station. multidirectional time division multiplex radio communication system according to claim 5 or 6, wherein. 8. The baseband signal processing circuit according to claim 1, wherein when the comparison circuit outputs a logical level “0”, the main signal and the control data are not transmitted to the next higher-level station without performing relay signal processing. multidirectional time division multiplex radio communication system according to claim 5 or 6, wherein.