JP2891011B2 - 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 base station transceiver used in a mobile communication system for performing two-way communication using the same frequency in a time-division manner. It is assumed that base stations of systems that provide services completely independently are installed in adjacent places.

[0002]

2. Description of the Related Art In recent years, in the field of mobile communication, there has been a shift from a conventional analog transmission system to a digital transmission system. This is because various services can be provided to subscribers by introducing digital transmission. As an issue in digitization, there is an access method of how to configure a wireless line. In the current analog system, a frequency is allocated to each communication line (FDMA system), and two frequency bands are prepared, and different frequency bands are allocated to respective uplink and downlink wireless lines (FDD system). On the other hand, in a digital system, attention is focused on a system in which uplink and downlink communications are performed using the same frequency in a time-division manner (TDD system), and a TDMA system in which one frequency is shared by a plurality of communication channels in a time-division manner. It is being studied for practical use. In particular, the TDD method has an advantage in that diversity as a measure against fading can be easily introduced.
As the system form, the FDMA / TDD system and the TD
Both MA / TDD schemes are being studied.

[0003] In a system using TDD, if burst synchronization and frame synchronization between base stations are not established, line switching during communication such as when moving between base stations may not work sufficiently. The simplest method is a method of separately providing a wired network connecting base stations and delivering a reference clock signal to each base station as shown in the schematic diagram of FIG. In this case, the configuration of the base station transceiver is configured to operate based on a reference clock supplied from the outside.

[0004]

With such a method of burst synchronization, there is no problem if the service provider in a certain area is limited to one company. However, when there are two or more independently operated systems in the same area, it is expected that there will be few situations where base stations of different operators are connected and cooperated while exchanging reference clocks. Is done. Accordingly, when base stations of different systems are installed immediately adjacent to each other, remarkable degradation of speech quality is expected due to mutual interference caused by a shift in burst transmission timing between base stations.

For example, in the case of FDMA / TDD, it is assumed that base stations of different systems are installed at relatively distant places with overlapping service zones as shown at point A in FIG. For example, there is a case where base stations of different systems are installed at intersections separated by about 200 m in the micro zone system. In such a case, assuming that each base station is communicating with the mobile station using the adjacent carrier frequency, it is assumed that the mobile station 1803 talking to the base station 1801 moves to the immediate vicinity of the base station 1802. In this case, the base station 1802 receives strong adjacent channel interference from the mobile station 1803. In order to avoid such interference, frame synchronization must be ensured so that transmission and reception timings within a frame between two systems are completely the same.

[0006] In addition, in a case where a pseudo signal is transmitted even when a signal from the base station is not used for a call, it is assumed that the base stations are located close to each other, and interference may occur. The problem is significant and requires frame synchronization. As shown in (a) of the example of TDMA / TDD in FIG. 13, when transmission is performed in a form in which both base stations are completely synchronized with each other, the mobile station of another system is closer to the mobile station of its own station for communication. Only when it is, it becomes an interference partner.
If they are not synchronized as in (b), interference occurs in two or more slots.

Therefore, even if the mobile station 1804 and the mobile station 1803 communicating with the base station 1802 in FIG. 18 come close to each other, only the downlink of one communication channel receives interference. In such a case, a method of avoiding a line having poor transmission path characteristics can be used.

On the other hand, as a conventionally known method for achieving synchronization without exchanging control signals via a wired network, Japanese Patent Application No.
There is a method shown in 1-136050. this is,
This is a method of receiving a TDMA multiplexed radio channel used in another system, demodulating the last burst, extracting a synchronization signal, and synchronizing burst and frame between the systems. In this method, it is good that the TDMA multiplexing degree is increased and all systems share one carrier frequency. However, in a system using a plurality of carriers, a receiver for extracting a control signal must be separately prepared at the same time. The cost of the apparatus increases.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a base station transceiver having a frame synchronizing means having a simple circuit configuration capable of establishing burst synchronization between base stations without connecting to a wired network.

[0010]

SUMMARY OF THE INVENTION A first transceiver according to the present invention is a communication system for performing bidirectional digital data communication between a mobile station and a base station. Synchronization circuit for establishing inter-system frame synchronization when there are a plurality of systems using the same frequency band which are operated completely independently in a base station transceiver used in a mobile communication system which performs time-sharing periodically. As follows: 1. an interference wave detection unit that outputs a signal indicating whether the power of the interference wave input during a time when the signal of the own station is not received at the time of a call start is higher or lower than a preset level; If no interference power can be detected at the time of receiving the output of the interference wave detection unit, it is set that the base stations of the other independent systems of the same system are not close to each other; If the interference wave power is greater than or equal to the value, an interference source position determination unit that performs a setting change that recognizes that the base station of the other system is close at the same time as outputting a line switching signal that changes the used carrier frequency 3. A function of receiving the output of the interference wave detector, synchronizing the output of the interference wave detector and the burst period of the own station with the burst period of the station of the other system, and the burst period synchronized with the burst period of the station of the other system. Output signal,
3. burst synchronization means; Upon receiving the output of the burst synchronization means, the frequency is divided by 、,
Receiving the output signal of the interference wave source position detecting section and the signal of which the frequency has been divided by 、, and when the interference wave power periodically exceeds a predetermined power every other slot; When the position of the station is not set to be close, frame synchronization is performed so that the timing of the uplink signal of the own station matches the time when the interference wave level increases,
A frame synchronizing unit that performs frame synchronization so that the downlink signal timing of the own station matches the time when the interference wave level is high when the position of the own station is set near to the base station of the other system; A transceiver having a circuit of:

As a reference example related to the present invention, another reference example will be described.
As a transceiver, a mobile communication system that performs bidirectional digital data communication between a maximum of N mobile stations and a base station by a TDMA system, and periodically performs time-division communication in both directions using only one carrier. Transmission / reception of the first subscriber, transmission / reception of the second subscriber, transmission / reception, transmission / reception of the third subscriber,... Transmission / reception of the Nth subscriber;
Or for a base station used in a system for receiving, transmitting, receiving, transmitting, receiving, transmitting,... The receiving and transmitting of the third subscriber in the order of the first subscriber. As a frame synchronization establishment circuit for establishing frame synchronization between systems in a case where a plurality of systems using the same frequency band operated completely independently exist in a transceiver, 1. an interference wave detection unit that outputs a signal indicating whether the power of the interference wave input during a time when the signal of the own station is not received at the time of a call start is higher or lower than a preset level; In response to the output of the interference wave detector, when the output signal of the interference wave detector continuously indicates that no interference wave exists, the interference power can be detected in a form that matches the cycle of every other slot. Sometimes, the base station of another independent system of the same system is set as not approaching; if the interference wave power exceeds a predetermined value continuously for two or more slots, the base station of the other system is set. 2. an interference source position detecting unit for performing setting change for recognizing that the station is approaching; A function of receiving the output of the interference wave detector, synchronizing the output of the interference wave detector and the burst period of the own station with the burst period of the station of the other system, and the burst period synchronized with the burst period of the station of the other system. Output signal,
3. burst synchronization means; 4. a frequency divider that receives the output of the burst synchronization means and divides the frequency by ２; When the output of the 分 frequency divider and the output of the interference source position detection unit are received, and the position of the own station is not set to be close to the base station of the other system, the timing of the uplink signal of the own station becomes the interference. Frame synchronization is performed so as to match the time when the wave level becomes high; when the interference wave power is continuously higher than a predetermined power over a plurality of slots, the position of the own station is close to the base station of the other system. If it is set, the uplink signal timing of the own station is adjusted to the even-numbered slot of the continuous interference wave slots, and the frame synchronization is controlled so that the transmission / reception timing of the call to each subscriber is synchronized. there are transceiver, characterized in that with a circuit consisting of: a frame synchronization unit for.

[0012] It should be noted that other reference examples related to the present invention.
As a transceiver , a mobile communication system that performs simultaneous two-way communication between a base station and a maximum of N mobile stations uses a method in which communication in both directions is periodically performed in a time-division manner using only one carrier. , Transmission and reception of the first subscriber, transmission of the second subscriber, transmission of the third subscriber, transmission of the Nth subscriber, reception of the first subscriber, reception of the second subscriber In a system in which reception, third subscriber reception,... Nth subscriber reception are performed in that order, the base station is a base station used in a system that transmits a pseudo signal even when there is no signal to be transmitted. In a station transceiver, as a frame synchronization establishing circuit for establishing inter-system frame synchronization when there are a plurality of systems using the same frequency band that are operated completely independently. 1. an interference wave detection unit that outputs a signal indicating whether the interference wave power input during a time when the signal of the own station is not received at the time of a call start is higher or lower than a preset level; Receiving the output of the interference wave detection unit; a function of synchronizing the output of the interference wave detection unit and the burst period of the own station with the burst period of the station of the other system; 2. Burst synchronization means for outputting The receiving interference wave detector output, counting the number of consecutive numbers及 beauty presence of interference slot contiguous with no interference wave the slot; number of consecutive no interference wave slot N
When the pulse for the first non-interfering slot is reached,
Output a pulse for the second non-interfering slot when the continuation is interrupted; output a pulse for the first interfering slot when the number of consecutive slots in which the interference wave exists reaches N; 3. a counter that outputs a pulse for the second interference slot; When receiving a pulse related to the first interference slot of the counter, change the setting to recognize that the base station of the other system is approaching; when receiving a pulse related to the first non-interference slot, 4. an interference source position determining unit that changes a setting for recognizing that the base station of the other system is not approaching and outputs a setting signal; 5. A 1 / 2N frequency divider which receives the output of the burst synchronization means and generates a signal indicating a downstream signal timing and a signal indicating an upstream signal timing in a frame; Receiving the setting signal of the interference source position determining unit; when the setting signal indicates that the interference source is far away, the 1 /
When the output of the 2N frequency divider is a signal indicating the upstream signal timing, the counting is preset so that it is controlled to be the last of the instantaneous downstream signal timing upon receiving the pulse, and the first non-interfering wave is controlled. The output of the 1 / 2N frequency divider is a signal indicating the downstream signal timing at the moment when the pulse regarding the second non-interfering wave is received, and the output of the 1 / 2N frequency divider at the moment when the pulse regarding the second non-interfering wave is received. When the up signal timing is reached, the counter is preset to control the down signal timing to start; when the setting signal indicates that the interference source is nearby, a pulse related to the first interference wave is issued. When the output of the 1 / 2N frequency divider is a signal indicating the upstream signal timing at the moment when the pulse is received, the counter is preset and the pulse is received at the instant when the pulse is received. There was controlled to be the end, the at the moment of receiving the pulses for the first interference wave 1/2
When the output of the N frequency divider is a signal indicating the downstream signal timing and the output of the 1 / 2N frequency divider is the upstream signal timing at the moment when the pulse regarding the second interference wave is received, there are transceiver, characterized by having a circuit made of a; vessel frame synchronization unit for controlling so as presets to downlink signal timing starts.

Further , another reference example relating to the present invention is provided.
As a transceiver , a mobile communication system that performs simultaneous two-way communication between a base station and a maximum of N mobile stations uses a method in which communication in both directions is periodically performed in a time-division manner using only one carrier. , The order of transmission / reception is determined by the transmission of the first subscriber,
Transmission of the third subscriber, transmission of the third subscriber,... Transmission of the Nth subscriber, reception of the first subscriber, reception of the second subscriber, reception of the third subscriber,. Base station uses the same frequency band that is operated completely independently in a base station transceiver used in a system that does not transmit a signal when there is no signal to be transmitted. As a frame synchronization establishment circuit that establishes frame synchronization between systems when a plurality of systems exist: 1. an interference wave detection unit that outputs a signal indicating whether the interference wave power input during a time when the signal of the own station is not received at the time of a call start is higher or lower than a preset level; Receiving the output of the interference wave detection unit; a function of synchronizing the output of the interference wave detection unit and the burst period of the own station with the burst period of the station of the other system; 2. Burst synchronization means for outputting The receiving interference wave detector output, counting the number of consecutive numbers及 beauty presence of interference slot contiguous with no interference wave the slot; number of consecutive no interference wave slot N
When the pulse for the first non-interfering slot is reached,
Output a pulse for the second non-interfering slot when the continuation is interrupted; output a pulse for the first interfering slot when the number of consecutive slots in which the interference wave exists reaches N; 3. a counter that outputs a pulse for the second interference slot; When receiving a pulse related to the first interference slot of the counter, change the setting to recognize that the base station of the other system is approaching; when receiving a pulse related to the first non-interference slot, 4. an interference source position determining unit that changes a setting for recognizing that the base station of the other system is not approaching and outputs a setting signal; 5. A 1 / 2N frequency divider which receives the output of the burst synchronization means and generates a signal indicating a downstream signal timing and a signal indicating an upstream signal timing in a frame; Receiving the setting signal of the interference source position determining unit; when the setting signal indicates that the interference source is far away, the 1 /
When the output of the 2N frequency divider is a signal indicating the upstream signal timing, the counting is preset so that it is controlled to be the last of the instantaneous downstream signal timing upon receiving the pulse, and the first non-interfering wave is controlled. The output of the 1 / 2N frequency divider is a signal indicating the downstream signal timing at the moment when the pulse regarding the second non-interfering wave is received, and the output of the 1 / 2N frequency divider at the moment when the pulse regarding the second non-interfering wave is received. When the up signal timing is reached, the counter is preset to control the down signal timing to start; when the setting signal indicates that the interference source is nearby, a pulse related to the first interference wave is issued. When the output of the 1 / 2N frequency divider is a signal indicating the upstream signal timing at the moment when the pulse is received, the counter is preset and the pulse is received at the instant when the pulse is received. There was controlled to be the end, the at the moment of receiving the pulses for the first interference wave 1/2
When the output of the N frequency divider is a signal indicating the downstream signal timing and the output of the 1 / 2N frequency divider is the upstream signal timing at the moment when the pulse regarding the second interference wave is received, there are transceiver, characterized by having a circuit made of a; vessel frame synchronization unit for controlling so as presets to downlink signal timing starts.

[0014]

The case where frame synchronization is essential between base stations of different systems is when adjacent channel interference power is large enough to affect communication quality. This is because when the interference power is small, they do not interfere with each other even if the timings of the frames are not synchronized with each other. Therefore, the burst synchronization method used in the base station transceiver according to the present invention transmits each TDD burst according to a signal indicating its own burst transmission timing at that time when the interference wave power is sufficiently small so as not to cause a problem. When the power of the interference wave is large, the signal indicating the burst and frame period of the interference wave extracted from the received interference wave signal is compared with the signal indicating the burst and frame period of the own station so that the local station can synchronize the two. A method of controlling the phase and the cycle of the frame cycle may be adopted.

Therefore, by transmitting the signal of the own station in accordance with the frame period extracted from the interference wave level detection signal, it is possible to avoid the adjacent channel interference problem as described above. In order to establish frame synchronization, it is essential that burst synchronization be established first.
For the burst synchronization, the method described in Japanese Patent Application No. 3-73983 can be used from the output of the interference wave level detection circuit. The signals indicating the frame period and phase of the interference wave detected from the interference wave level are FDMA / TDD and TDMA / TD.
The appearance of the phenomenon differs between the frame configurations of D.
Therefore, the algorithms for frame synchronization are as follows.

In the case of FDMA / TDD, a base station (hereinafter, FS-B) of a system different from the own station (hereinafter, system B)
When the mobile station (hereinafter referred to as MS-B) of the other system and the mobile station of the other system are both distant, and when FS-B and MS-B are both close, the output of the interference wave detection circuit shows a constant level as shown in FIGS. Although the burst period cannot be detected, FS-B
Whether the position is near or far from the own station can be specified.

On the other hand, the burst period and the frame period can be detected when the FS-B is located far away and the mobile station MS-B of the partner system is close, or when the FS-B is close and M
When SB is far, the moment when the interference wave is detected and the moment when the interference wave is not detected are alternately repeated as shown in FIG. Therefore, it cannot be determined whether FS-B is far or near.

When a base station and a mobile station of a system different from the own station are located near each other, an interference wave is always detected as shown in FIG. Therefore, when this phenomenon is observed, it is determined that FS-B is close.

By obtaining such a judgment result, FIG.
When the waveform is obtained, when it is determined that the FS-B is close, the downlink signal is assigned to the timing at which the interference wave is observed, and when it is determined that the FS-B is far, the timing at which the interference wave is observed If an upstream signal is assigned to the system, frame synchronization can be obtained between the two systems.

In the case of TDMA / TDD, it differs depending on the frame configuration. As shown in FIG. 16 (a), the transmission and reception order of the first subscriber is transmission, reception, transmission of the second subscriber, reception, transmission of the third subscriber, reception,... Transmission of the Nth subscriber. , Reception order; or first subscriber's reception, transmission, second
Receiving and transmitting subscribers, receiving and transmitting third subscribers, ...
When the reception and transmission of the Nth subscriber are performed in this order, the following is performed.

In this case, the shape of the interference wave detection waveform is FS-
As shown in FIG. 16 (b), the interference wave is continuously observed for two or more slots only when B is close.
Therefore, when interference waves are continuously observed for two or more slots, it is determined that FS-B is close, and when not observed, it is determined that FS-B is not close.

When the FS-B is not close, an upstream signal is assigned to the timing at which the interference wave is observed, and the FS-B is assigned.
When it is determined that B is close, the head of the slot group in which the interference wave is continuously observed for two or more slots is always the downlink signal of the system B, so that the downlink signal is allocated to the own system. You just need to set up a frame.

[0023] As shown in FIG.
Transmission of the second subscriber, transmission of the third subscriber, transmission of the third subscriber, transmission of the Nth subscriber, reception of the first subscriber, reception of the second subscriber, reception of the third When the reception of subscribers,..., The reception of the Nth subscriber is performed in this order, the following is performed.

When the base station (FS-B) of the system B is located far away, a phenomenon occurs in which no interference wave is observed over N slots or more within a time length of 2N slots. Therefore, over a certain period of time (for example, two days)
If there is a moment when the number of frames for which no interference wave is continuously detected during the time of 2N slot length becomes smaller than N, FS
-B is determined to be close, and 2N continues for a certain period of time.
If a phenomenon in which an interference wave is not detected continuously for N or more slots during the slot length is observed, the base station of the partner system is determined to be far.

With regard to frame synchronization, when it is determined that FS-B is far, a base station of a system different from the own station is located far away continuously for N slots or more, and a mobile station of the partner system is near. In such a case, there is a slot where an interference wave is intermittently detected as shown in FIG. At this time, when the presence of the interference wave is detected, the base station of the partner system is in the reception mode. Therefore, it is sufficient that the own station is in the reception mode.

When a base station of a system different from the own station is located near and a mobile station of the partner system is far away, FIG.
As shown in (d), the time is divided into a time when the interference wave is continuously detected over several slots and a time when the interference wave is not detected. At this time, when the presence of the interference wave is continuously detected, the base station of the partner system is in the transmission mode. Therefore, it is sufficient that the own station is in the transmission mode.

If both the base station and the mobile station of a system different from the own station are located close to each other, whether an interference wave is detected continuously over several slots as shown in FIG. Divided into single detection times. When an interference wave is continuously detected over several slots, the base station of the partner system is in the transmission mode. Therefore, it is sufficient that the own station is in the transmission mode.

In the case of TDMA / TDD, T
If an interference wave is detected for the same number of slot times as the number of multiplexed DMAs, it is determined that the interference source base station is close, and during that time, the own station can set the transmission timing, thereby adjusting the frame period.

When there is no continuous interference wave, there is a time period during which no interference wave is detected over the same number of slot times as the number of multiplexed TDMAs. If the slot in which the interference wave is detected immediately after such time is determined to be the first slot in the reception mode, frame synchronization can be adjusted.

The interference can be reduced by performing frame synchronization control using the above-described properties.

[0031]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. FIG. 1 shows the first
I from the frame synchronization unit or the like included in the transceiver of the present invention
1 shows an embodiment of a frame synchronization establishing circuit according to the present invention. Terminal 110
Is a composite wave of the desired signal and the interference wave.
The interference wave detection means 120 outputs a signal indicating whether the signal power input from the input terminal 110 is higher or lower than a preset level. As a power detection circuit, a detection circuit using a rectifier using a diode is well known, and power level determination can be easily realized by a voltage comparator using an operational amplifier.

The burst synchronization means 130 receives the output of the interference wave detection means 120 and controls its own burst transmission cycle and phase so that its own burst transmission cycle and the burst transmission cycle and phase of the interference wave station are synchronized. . On the other hand, the interference source position detection unit 140 outputs the initial value “0” at the time of activation, assuming that the interference source is not close, receives the output of the interference wave detection unit 120, and continuously detects the interference wave. For the first time, the position of the interference source is set to be close and "1" is output.

As shown in FIG. 5, the interference source position detecting section 140 is provided with the burst synchronizing means 1 input from the terminal 51.
30 outputs are input to the clock terminal of the counter 53, and the output of the interference wave detection unit input from the terminal 52 is input to the reset terminal of the counter 53. As a result, the number of slots in which interference waves are continuously detected is counted. The output of the counter is input to the set terminal of the set / reset flip-flop 54, and when the counter value exceeds 2, the output becomes "1".
It can be realized if it is set to.

As a result of the control, the burst synchronizing means 130 outputs a burst cycle signal for the own station synchronized with the burst cycle of the interference wave to the frame cycle generating section 150 as a frame synchronizing section, and combines the output with the output of the interference source position detecting section 140. To generate a frame period signal that matches the frame period of the interference source base station. In order to generate a frame period signal from a burst period signal, it is sufficient to divide the frequency by 、, but the phase must be converted by 180 degrees depending on the position of the interference source base. This conversion can be performed by inputting the output of the frequency divider 151 to the exclusive OR circuit together with the output of the interference source position detection unit 140.

FIG. 6 shows an embodiment of the burst synchronization means 130 of the present invention. The output of the interference wave detecting means 120 shown in FIG . In the phase comparator 62, the multiplier 621 multiplies the input signal from the terminal 61 by the output of the burst cycle signal generator 63 which is a signal indicating the burst cycle and phase of the own station. At this time, the output of the burst period signal generation unit 63 is -H Volt and + H Volt.
And a voltage-controlled reference signal generator 64
It is obtained by dividing the 0 output. The output of the multiplier 621 is integrated by the integrator 622, and the output is input to the voltage control type reference signal generator 64 to control the burst cycle and phase. As a result, the center of the pulse in FIG. 14B, which is the output of the interference wave detecting means 120, coincides with the falling edge of the pulse in FIG. And the burst cycle of the own station are synchronized. A part of the output of the burst cycle signal generator 63 synchronized as a result of the control is output to the frame cycle generator 150.

It should be noted that the present invention relates to the first embodiment of the present invention.
Some have a frame synchronization unit shown in FIG.
Below, for reference, a transceiver equipped with this frame synchronization unit
Will be described. The signal input from the terminal 210 is a composite wave of the desired signal and the interference wave. In response to the signal input from the input terminal 210 in the interference wave detecting means 220 and the signal indicating whether the signal is being transmitted or waiting in the own station, the signal power input during the time when the signal of the own station is not received is preset. And outputs a signal indicating whether the level is higher or lower than the set level. In the burst synchronization means 130, the interference wave detection means 12
Upon receiving the 0 output, the burst transmission cycle and phase of the own station are controlled so that the burst transmission cycle of the own station and the burst transmission cycle and phase of the interference wave station are synchronized. The interference source position detector 240 outputs “0” as the initial value, and outputs the interference wave detector 220
When the interference wave is continuously detected for two or more slots, the position of the interference source is set to be close and "1" is output. The signal power detection circuit, the burst synchronization circuit, and the interference source position detection unit can be realized with the same configuration as that shown in FIG.

As a result of the control, the burst synchronization means 230 outputs a burst cycle signal for the own station synchronized with the burst cycle of the interference wave to the frame cycle generation section 250 as a frame synchronization section, and combines it with the output of the interference source position detection section 240. To generate a frame period signal that matches the frame period of the interference source base station. According to the second invention, the procedure of transmission / reception signals is viewed from the base station, and transmission / reception of the first subscriber, transmission / reception of the second subscriber, transmission / reception of the third subscriber,. In the order of transmission and reception of the first subscriber, or reception of the first subscriber, transmission, reception of the second subscriber, transmission, reception of the third subscriber,
Since transmission,..., Reception and transmission by the Nth subscriber are performed in this order, the frame cycle generation unit outputs a signal indicating only transmission and reception timings and a signal indicating communication timing for each subscriber. The hatched lines described in the output of the frame period generation unit 250 in FIG. 2 indicate that two types of signals are output.

To generate a signal indicating only the transmission / reception timing from the burst period signal, it is sufficient to divide the frequency by 、.
The phase must be converted by 180 degrees depending on the position of the interference source base station. If the level of the interference wave is high due to consecutive slots in the interference wave detection, the second slot is the system B
Is the upstream signal. Therefore, the objective can be achieved by removing the 1/2 frequency divider clock only at the timing of the downstream signal in the second slot of the continuous interference wave existence slot.

FIG. 7 shows an embodiment of the frame period generating section 250. The input signal from the terminal 701 is a counter 53 that counts the number of slots receiving continuous interference. Upon receiving this input signal, the pulse generator 702 generates a pulse when the value of the input signal is “2”.

A burst period signal from the burst synchronization circuit 230 is input from a terminal 703. A signal from a terminal 703 is input to a 分 frequency divider 705 via an AND circuit 704. The signal indicating the transmission / reception timing, which is the output of the。 frequency divider 705, indicates that the signal is a high-level signal and the low-level signal is a low-level signal. This signal is output from terminal 707 and input to counter 706. A signal indicating the call timing of each subscriber, which is the output of the counter 706,
8 to output.

The output of the 1/2 frequency divider 705 is input to the AND circuit 710 together with the output of the pulse generator 702 via the level inverter 709. AND circuit 710
The pulse is output only when the interference wave is detected for two consecutive slots and the second slot is the timing of the downlink signal at the own station. The output of the AND circuit 710 is delayed by a half burst period in the flip-flop 712 due to the input signal from the terminal 703 inverted by the level inversion circuit 711.
The output of the flip-flop 712 is input to the AND circuit 704. By taking such a configuration, the AND circuit 710
Outputs a pulse. One input clock to the 1/2 frequency divider 705 is lost only when an interference wave is detected for two consecutive slots and the second slot is the timing of a downlink signal at the own station. As a result, the phase of the output of the 1/2 frequency divider 705 becomes 1
It changes by 80 degrees.

In connection with the above-described first embodiment of the present invention, there is an embodiment including a frame synchronization section shown in FIG.
Hereinafter, a transceiver including the frame synchronization unit will be described for reference. The frame synchronization unit shown in FIG. 3 is basically the same as that shown in FIG. The difference from FIG. 2 is the configuration of the interference source position detection unit 340 and the frame cycle generation unit 350.

The interference source position detecting section 340 outputs the initial value "0" and receives the output of the interference wave detecting section 220, and continuously receives N (N is the number of multiplexed TDMA) slots. When the existence of the time during which no interference wave is detected is observed, the position of the interference source is set to be far and "0" is output. Further, when an interference wave is continuously detected over N (N is the number of multiplexed TDMA) slots, the position of the interference source is set to be close and "1" is output. Burst synchronization means 23
0 outputs a burst period signal for the own station synchronized with the interference wave burst period to the frame period generation section 350,
The frame cycle generation unit 350 includes an interference source position detection unit 340
A frame period signal that matches the frame period of the interference source base station is generated together with the output. In order to generate a frame period signal from a burst period signal, it is only necessary to determine the head burst and divide the frequency by ＮN simultaneously. The method of adjusting the phase of the frame period signal differs depending on the position of the interference source base station.

FIG. 8 shows an embodiment of the interference source position detecting circuit of FIG. The output of the burst synchronization circuit 220 input from the terminal 81 is input to the clock terminal of the first counter 83, and is simultaneously inverted and input to the clock terminal of the second counter 84. Interference wave detector 22 input from terminal 82
The 0 output is input to the reset terminal of the first counter 830 and simultaneously inverted and input to the reset terminal of the second counter 840. The first counter 830 counts the number of slots where there is no continuous interference wave, and the second counter 8
4 counts the number of slots in which continuous interference waves exist. The output of the first counter 83 and the output of the second counter 84 are input to a first comparator 85 and a second comparator 86, respectively. The first and second comparators output a pulse only when the input is equal to N. Outputs of the first comparator 85 and the second comparator 86 are input to reset terminals of a first timer 87 and a second timer 88, respectively. First timer 87
Outputs a pulse to the set terminal of the RS flip-flop 89 after counting a predetermined time. The first timer 87 is reset to 0 when it receives a pulse from the comparator 85 before reaching a predetermined time. Therefore, if the continuous number of slots in which no interference wave is detected for a certain period of time is N or less, it is determined that the interference source base station is close. When the second timer 88 counts a predetermined time, it outputs a pulse to the reset terminal of the RS flip-flop 89. The second timer 88 is reset to 0 when it receives a pulse from the comparator 86 before reaching a predetermined time. Therefore, if the continuous number of slots for detecting interference waves for a certain period of time continues to be N or less, it is determined that the interference source base station is not close.

FIG. 9 is a diagram showing one embodiment of the frame period generating section. The output of the burst synchronization circuit 230 is the switch 9
2 and the interference source position detection circuit 340 from the terminal 91
Controlled by output. When the interference source position detection signal indicates that the interference source is not close, the output of the burst synchronization circuit is input to the first frame synchronization control circuit 93. When the interference source position detection signal indicates that the interference source is close, The output of the burst synchronization circuit is input to the second frame synchronization control circuit 94.

In the first frame synchronization control circuit, a burst synchronization signal is input to a 1 / N frequency divider 932 and a counter 934, and the 1 / N frequency divider 932 outputs a signal indicating transmission and reception timing. At this time, the signal indicating the transmission / reception timing is the High level and the uplink signal Low.
level indicates the timing of the downstream signal. This signal is output from the terminal 933. In addition, the counter 934 inputs the interference wave detection signal to the reset terminal, and counts the continuous number of slots that do not receive interference. The output of the counter 934 is input to a comparator 935, and the value of the counter is N
Output a pulse from the first output of the comparator when
When the value of the counter is equal to or more than N + 1, a High level signal is output from the second output of the comparator. The first output of the comparator and the output of the 1 / N divider are input to a first AND circuit 936,
The output is input to a preset terminal of the 1 / N frequency divider 934. If the own station is already in the uplink signal mode when the slot receiving no interference wave is the Nth consecutive slot, the 1 / N frequency divider 9 is added to the last burst position in the downlink mode.
Adjust the state of 32. The second output of the comparator is input to the second AND circuit 937 together with the interference wave detection signal, and outputs the last burst position when the number of slots in which no interference wave is detected becomes N + 1 or more. The third AND circuit 938 outputs the output of the second AND circuit 937 and the inverted 1 / N frequency divider 9
At the end of the continuation when the slots receiving the 32 outputs and receiving no interference wave continue continuously for N or more slots, if the own station is already in the mode of the downlink signal, the last burst position of the uplink mode is The state of the 1 / N frequency divider 932 is adjusted.

In the second frame synchronization control circuit, a burst synchronization signal is input to the counter 941. Counter 94
1 inputs the inverted signal of the interference wave detection signal to the reset terminal, and counts the continuous number of slots that do not receive interference. The output of the counter 941 is input to the comparator 942, and outputs a pulse from the first output of the comparator when the value of the counter is equal to N, and outputs a high level signal from the second output of the comparator when the value of the counter is N + 1 or more. Put out. The first output of the comparator and the output of the 1 / N frequency divider are input to a first AND circuit 943, and the output is input to the preset terminal of the 1 / N frequency divider 934. If the own station is already in the mode of the uplink signal when the slot receiving the interference wave is the Nth consecutive slot, the state of the 1 / N divider 932 is adjusted to the last burst position of the downlink mode. The second output of the comparator is input to the second AND circuit 944 together with the interference wave detection signal, and outputs the last burst position when the number of slots in which no interference wave is detected becomes N + 1 or more. Third AND circuit 945
When the output of the second AND circuit 946 and the inverted output of the 1 / N frequency divider 932 are received and the slots that receive no interference wave continue for N or more slots, and the continuation ends,
If the own station is already in the downlink signal mode, the state of the 1 / N divider 932 is adjusted to the last burst position in the uplink mode.

In connection with the above-mentioned first embodiment of the present invention, there is also provided one having a frame synchronization section shown in FIG.
Hereinafter, a transceiver including the frame synchronization unit will be described for reference. The basic configuration of this frame synchronization unit (FIG. 4) is also the same as that of FIG. The difference from FIG. 3 is the configuration of the interference source position detection unit 440 and the frame cycle generation unit 450.

FIG. 10 shows the interference source position detecting circuit 440 of FIG.
1 shows an embodiment. The output of the burst synchronization circuit 220 input from the terminal 1001 is input to the clock terminal of the counter 1003, and the output of the interference wave detection unit 220 input from the terminal 1002 is input to the reset terminal of the counter 1003. The counter 1003 counts the number of slots in which no continuous interference wave exists. The output of the counter 1003 is input to the comparator 1004. The input of the comparator 1004 is N
A pulse is output only when is equal to The output of the comparator 1004 is input to the reset terminal of the SR flip-flop 1005. The output of the burst synchronization circuit 220 input from the terminal 1001 is input to the clock terminal of the second counter 1006, and the interference wave detector 220 input from the terminal 1002 is input.
The inverted signal of the output is input to the reset terminal of the counter 1006. The counter 1006 counts the number of slots where there is no continuous interference wave. The output of the counter 1006 is
It is input to the comparator 1007. The input of the comparator 1007 is
A pulse is output only when it is equal to N. Comparator 1007
Is input to the set terminal of the SR flip-flop 1005.

FIG. 11 shows the frame period generator 450 of FIG.
FIG. 3 is a diagram showing one embodiment of the present invention. The output of the burst synchronization circuit 230 is input to the switch 1120, and is controlled by the output of the interference source position detection circuit 340 from the terminal 1101. When the interference source position detection signal indicates that the interference source is not close, the output of the burst synchronization circuit is input to the first frame synchronization control circuit 1103. When the interference source position detection signal indicates that the interference source is close, Burst synchronization circuit output
It is input to the second frame synchronization control circuit 1100.

The first frame synchronization control circuit has the same configuration as the first frame synchronization control circuit 93 in FIG.

The second frame synchronization control circuit receives the output of the 2N-base counter 1102 that has received the output of the burst synchronization circuit 210 as a write address, inputs the output of the interference wave detection unit 220, and writes it to the RAM 1103. When the interference wave detection result corresponding to each burst is written for one cycle,
Of the recorded signals, I (I is any value from 1 to N)
, The I-th signal (downlink quality) and the I + N-th signal (uplink quality) are sequentially output, and the I-th signal is inverted to obtain the I-th signal.
The signal is input to the AND circuit 1104 together with the + Nth signal.
The output of the AND circuit 1104 has interference on the uplink,
This shows a case where there is no interference on the downlink. Such a phenomenon cannot occur when the interference source base station is close to the base station, so that the phase of the frame period is different from that of the system that is the interference source. The output of the AND circuit 1104 and the read address are input to the phase control circuit 1105, and the value of I is N / 2.
In the following cases, a signal for extracting a pulse to delay the phase is output to the 1 / N frequency dividing circuit 932, and the value of I becomes N / 2.
In the above case, a signal for advancing two by one pulse so as to advance the phase is output to the 1 / N frequency dividing circuit 932.

[0053]

By configuring a base station transceiver having a frame synchronization establishing circuit having such a function , the burst transmission timing and period of the own station can be synchronized with the burst period of the interference wave, and can be independently performed. Even in an environment where a plurality of operating system base stations are installed adjacent to each other, it is possible to suppress interference between systems and provide high quality communication.

In the embodiment described here, the TDMA / FD system in which the up and down frequencies are particularly different among the TDMA systems.
Although the description has been made assuming D, the present invention can also be used for a TDMA / TDD system which has been studied in a small-scale system such as an office cordless system in recent years and has the same uplink and downlink frequencies and performs time division communication. Especially TDMA /
In TDD systems, interference problems are normal TDMA / FDD
More severe, a greater effect can be expected with the transceiver of the present invention.

[Brief description of the drawings]

FIG. 1 is a diagram showing one embodiment of the first invention.

FIG. 2 shows a reference example related to one embodiment of the first invention.
Figure.

FIG. 3 shows a reference example related to one embodiment of the first invention.
Figure.

FIG. 4 shows a reference example related to one embodiment of the first invention.
Figure.

FIG. 5 is a diagram showing an embodiment of an interference source position detecting unit according to the first invention.

FIG. 6 is a diagram showing an embodiment of a burst synchronization circuit in the transceiver according to the present invention.

FIG. 7 is a diagram illustrating an example of a frame cycle generation circuit in FIG . 2;

FIG. 8 is a diagram illustrating an example of an interference source position detection unit in FIG . 3;

FIG. 9 is a diagram illustrating an example of a frame cycle generation circuit of FIG . 3;

FIG. 10 is a diagram illustrating an example of an interference source position detection unit in FIG . 4;

11 shows an example of the frame period generation circuit of FIG .
FIG.

FIG. 12 is a diagram showing an outline of a base station transceiver equipped with a conventional burst synchronization system.

FIG. 13 is a diagram showing a state of a TDMA line between different systems.

FIG. 14 is a diagram showing signals in respective units according to the embodiment of the present invention.

FIG. 15 is a signal diagram showing an overview of FDMA / TDD interference wave observation.

FIG. 16 shows interference waves for the example of FIG. 2 for TDMA / TDD.
FIG. 3 is a signal diagram showing an overview of observation.

FIG. 17 relates to the example of FIGS. 3 and 4 of TDMA / TDD.
FIG. 3 is a signal diagram showing an outline of interference wave observation.

FIG. 18 is a conceptual diagram of a mobile communication system using a TDMA system.

[Explanation of symbols]

 110 first input terminal 120 interference wave detection means 130 burst synchronization means 140 interference source position detection section 150 transmission signal generation section 160 output terminal 210 input terminal 220 phase comparator 221 multiplier 222 integrator 230 burst period signal generation section 240 voltage Control type reference signal generator 250 output terminal

Claims (1)

(57) [Claims] 1. A base station used in a mobile communication system in which bidirectional communication is periodically performed in a time-division manner using only one carrier among communication systems for performing bidirectional digital data communication between a mobile station and a base station. As a frame synchronization establishment circuit that establishes inter-system frame synchronization when there are multiple systems using the same frequency band that are operated completely independently in the office transceiver, it does not receive its own signal at the start of a call An interference wave detection unit that outputs a signal indicating whether the power of the interference wave input at time is higher or lower than a preset level, and receiving the output of the interference wave detection unit, no interference power was detected. In some cases, it is set that other independent base stations of the same system do not approach each other, and the interference wave power does not exceed a predetermined value continuously for at least two slots. If it is, an interference source position determining unit that performs a setting change that recognizes that the base station of the other system is approaching at the same time as outputting a line switching signal that changes the used carrier frequency, and outputs the interference wave detecting unit. Receiving the interference wave detector and synchronizing the burst cycle of the own station with the burst cycle of the station of the other system, and outputting a burst cycle signal synchronized with the burst cycle of the station of the other system. Means for receiving the output of the burst synchronization means and dividing the frequency by 、.
/ 2 and the output of the interference wave source position detection unit, and when the interference wave power periodically becomes equal to or higher than a predetermined power every other slot, the base station of the other system transmits its own signal to the base station of the other system. When the position is not set to be near, frame synchronization is performed so that the timing of the uplink signal of the own station matches the time when the interference wave level becomes high, and the position of the own station is close to the base station of the other system. And a frame synchronizing unit that performs frame synchronization so that the downlink signal timing of the own station matches the time when the interference wave level increases.