JPH08307929A - Peripheral base stations and synchronizing method in them - Google Patents

Abstract

PURPOSE: To provide peripheral base stations solved with the problem that call signals transmitted from the respective peripheral base stations can not speedily be synchronized and to provide a synchronizing method for them. CONSTITUTION: The peripheral base station where a GPS reception part 13 generates a GPS clock based on GPS time received from a GPS satellite 20, a UW detection part 16 detects the unique word(UW) of a call signal received from a central base station 1, a phase delay detection part 12 detects a phase delay time before the generation of the next GPS clock after the UW detection time and timing for reading the call signal from DPRAM is adjusted to become next GPS clock generation time by changing a read address on DPRAM in a phase delay correction part 11, which is equivalent to the phase delay time by a delay address generation part 17, and the synchronizing method in the station are provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a peripheral base station in TDM mobile communication, and more particularly to a peripheral base station capable of correcting a phase delay of a calling signal and transmitting the calling signals synchronously all at once based on GPS time. The present invention relates to a base station and a synchronization method in the base station.

[0002]

2. Description of the Related Art A conventional TDM synchronization method between mobile communication base stations will be described with reference to FIGS. FIG. 5 is a schematic configuration diagram of a conventional TDM synchronization system between mobile communication base stations, and FIG. 6 is a timing chart showing a conventional TDM synchronization method between mobile communication base stations.

A TDM (Time Division Multiplex:
Time division multiplexing) communication is a communication method in which, when one transmission path is shared by a number of channels, pulse signals shifted in time by the number of channels are arranged and transmitted. The modulation methods include pulse amplitude modulation (PAM) and pulse width modulation (PW).
N), pulse position modulation (PPM), pulse number modulation (PN
M), pulse code modulation (PCM), etc.

First, a schematic configuration of a conventional TDM synchronization system between mobile communication base stations will be described with reference to FIG. As shown in FIG. 5, the conventional TDM synchronization system between mobile communication base stations is basically composed of a central base station 1 ', peripheral base stations 2', and a receiver 5, and is called a central base station 1 '. Each of the plurality of peripheral base stations 2'is connected by a line (B signal relay line).

The central base station 1'is connected to the network, receives a call signal from the network, and simultaneously transmits the call signal to a plurality of peripheral base stations 2'via B signal relay lines. . The peripheral base station 2'is provided for each area, and in the example of FIG. 5, three peripheral base stations 2'-1,
2'-2 and 2'-3 are provided.

The internal configuration of the peripheral base station 2'will be further described. The peripheral base station 2'includes a phase correction unit 6, a transmission unit 7, a phase correction antenna 3, and a peripheral base station antenna 4. It is configured.

Here, the peripheral base station antenna 4 is an antenna for transmitting a calling signal to the receiver 5, and the transmitting unit 7 transmits a calling signal using the peripheral base station antenna 4. Is.

Further, in the phase corrector 6, if a carrier line is used as the B signal relay line, a delay occurs at the time when the paging signal arrives at the peripheral base station 2'due to the distance or the like, and each peripheral base station 2'is delayed. Since the arrival times are different and the timings for transmitting the calling signals do not match, each peripheral base station 2 '
This is for performing a correction for synchronizing the transmission timing in. The phase correction antenna 3 is an antenna used for the above correction. The operation of the phase corrector 6 will be described later with reference to FIG.

The receiver 5 receives the ringing signal transmitted from the peripheral base station 2 ', determines whether or not the signal is addressed to itself, and if the signal is addressed to itself, acquires the signal contents,
The alarm sound is generated and displayed.

Next, a conventional TDM synchronization method between mobile communication base stations will be described with reference to FIG. First, when a calling signal is transmitted from the network to the central base station 1, the central base station 1 sends the calling signal to the peripheral base stations 2'-1, 2'-2, 2'-3 via the B signal relay line. To transmit. Then, the peripheral base station 2'corrects the delay time when compared with the phase of another peripheral base station 2'which should be the reference phase.

Peripheral base station 2 '(especially peripheral base station 2'-
To specifically explain the correction of the delay time in 2), the peripheral base station 2'-2 receives the ringing signal transmitted from the peripheral base station antenna 4 of its own station by the phase correction antenna 3 of its own station, Next, the call signal from the peripheral base station 2'-1 to be used as the reference phase is received, and the phase delay Δt1 of both is detected from the synchronization code included in both call signals (see FIG. 6 (a)). .

Then, the phase correction unit 6 of the peripheral base station 2'-2.
Then, Δt1 is the time for one slot in TDM Δt0
Then, the transmission timing is adjusted so that, and one dummy slot is added to the calling signal (see FIG. 6B). Then, from the transmission of the next call signal, the peripheral base station 2 '
-1 can be synchronized with the peripheral base station 2'-2.

Further, with reference to the corrected phase of the peripheral base station 2'-2, the phase difference Δ with the ringing signal of the peripheral base station 2'-3 is set.
Similarly, t2 (see FIG. 6C) is corrected to establish the synchronized state. If the number of peripheral base stations 2'is increased, the phase of the calling signal between the peripheral base stations is similarly corrected.

Such a conventional TDM between mobile communication base stations
For the synchronization method, see NEC Res. & Develop., No. 8
4 January, 1987, T. Kuki et al "High Capaci
tyRadio Paging System ”.

[0015]

However, in the conventional TDM synchronization method between mobile communication base stations, the delay time is corrected so that one of the other peripheral base stations establish synchronization with the reference peripheral base station. However, because of the sequential transmission synchronization method in which the delay time is sequentially corrected on a one-to-one basis such that one station of another peripheral base station establishes synchronization with the corrected peripheral base station as a reference, There is a problem that a complicated process is required until the synchronization is finally established and the delay correction completion time increases in proportion to the number of peripheral base stations.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a peripheral base station capable of quickly establishing synchronization of a calling signal transmitted from each peripheral base station, and a synchronization method therefor. To aim.

[0017]

The invention according to claim 1 for solving the above-mentioned problems of the prior art is a peripheral base station for receiving a calling signal transmitted from a central base station and transmitting it to a portable unit. , GPS using satellite communication from GPS satellites
A receiving unit that receives time and generates a GPS clock based on the GPS time; a unique word detecting unit that detects a unique word of the calling signal and outputs a detection signal;
A phase delay detecting section for detecting a phase delay from the generation of the detection signal to the next GPS clock generation; and a delay address generating section for generating a delay address corresponding to the phase delay based on the detected phase delay. A clock generator that generates a clock with a shorter period from the GPS clock, a write address generator that counts the clock with a shorter period to generate a write address, and the generated write address to the generated write address. An address adder for adding a delayed address to generate a read address, and a storage for storing the received calling signal, and writing at a position of the storage indicated by the write address, the address indicated by the read address. A phase delay correction unit that reads and outputs from the position of the storage unit, and a transmission unit that transmits the ringing signal output from the phase delay correction unit The phase delay is corrected after receiving the ringing signal, and each peripheral base station can simultaneously transmit the ringing signal to the receiver in synchronization with the next GPS clock. It is possible to quickly establish the synchronization of the paging signal transmitted from each peripheral base station.

According to a second aspect of the present invention for solving the above-mentioned problems of the conventional example, in the synchronizing method in the peripheral base station according to the first aspect, the write address generating section outputs a clock output from the clock generating section. To generate a write address, which is output to the phase delay correction unit and output to the address addition unit, and the address addition unit generates the delay address generation unit according to the phase delay detected by the phase delay detection unit. The input delay address is added, and added to the write address and output as a read address to the phase delay correction unit. The phase delay correction unit writes a call signal in the storage unit according to the write address, and stores the storage address. When the read address is read from the read address and the read of the delay address corresponding to the phase delay is completed, the read address is changed to the write address. And the phase delay correcting unit outputs the calling signal to the transmitting unit from the position of the storage unit indicated by the read address, and corrects the phase delay after receiving the calling signal, The next G
Each peripheral base station can simultaneously transmit a calling signal to the receiver in synchronization with the PS clock, and the synchronization of the calling signal transmitted from each peripheral base station can be quickly established.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described with reference to the drawings. A peripheral base station according to an embodiment of the present invention is used in a TDM synchronization system between mobile communication base stations, and has a GPS (Global Positioning S
The GPS clock (GPSCLK) is generated from the GPS time received from the satellite using satellite communication, the unique word of the calling signal received from the central base station is detected, and the next GPSCLK is detected when the unique word is detected.
The phase delay time until the occurrence is detected, and the read address on the dual port RAM (DPRAM) corresponding to the phase delay time is changed to adjust the timing for reading the call signal from the DPRAM so that it will be the next GPSCLK occurrence. By doing so, each peripheral base station can simultaneously transmit the call signal to the receiver in synchronization with GPSCLK, so that the call signal can be quickly synchronized.

First, the configuration of a TDM synchronization system between mobile communication base stations in which the peripheral base stations of this embodiment are used will be described with reference to FIG. FIG. 1 is a schematic configuration diagram of a TDM synchronization system between mobile communication base stations according to an embodiment of the present invention. It should be noted that parts having the same configuration as in FIG.

The TDM synchronization system between mobile communication base stations of this embodiment is basically the same as the conventional one, and the central base station 1
And a plurality of peripheral base stations 2 and a receiver 5, and the information transmitted from the GPS satellite 20 is used as a feature of this embodiment. However, the method of controlling transmission of a paging signal in the central base station 1 of the present embodiment is different from that of the conventional central base station 1 ', and the central base station 1 of the present embodiment further includes a GPS antenna 14. This is different from the conventional central base station 1 '. In addition, the conventional phase correction unit 6 is provided inside the peripheral base station 2 of this embodiment.
Also, the point that the synchronizing circuit section 10 and the GPS antenna 14 are provided instead of the phase correcting antenna 3 is different from the conventional peripheral base station 2 '.

Next, the T between mobile communication base stations of the present embodiment
Each part of the DM synchronization system will be specifically described.
Description of the same components as the conventional one will be omitted, and only the characteristic parts of the present embodiment will be described. GPS satellite 2
0 is an orbiting satellite used in the satellite navigation system developed by the US Department of Defense for military use, which has a highly accurate atomic clock inside and constantly sends out periodic continuous signals based on a fixed time. This periodic signal is referred to as a GPS time signal here (refer to “Mobile Communication” Masashi Shinji, edited by Maruzen Co., Ltd., September 1989, p264). The GPS antenna 14 is an antenna that receives a signal (GPS time signal) periodically sent from the GPS satellite 20.

The central base station 1 transmits a paging signal to the receiver 5 received from the network to a plurality of peripheral base stations 2 via the B signal relay line as in the conventional case. The central base station 1 is characterized in that it receives a GPS time signal sent from a GPS satellite 20 and
Based on the S time signal, a 1-second periodic pulse (hereinafter,
"GPS clock" or "GPSCLK") is generated, and a calling signal is transmitted to the peripheral base station 2 at the timing of the generated GPSCLK.

The peripheral base station 2 receives the ringing signal transmitted from the central base station 1 in the synchronizing circuit section 10 via the B signal relay line, and generates a clock based on the GPS time transmitted from the GPS satellite 20. The calling signal is transmitted via the transmission unit 7 in synchronization with the above.

Here, the internal configuration of the synchronization circuit section 10 of the peripheral base station 2 of the present embodiment will be specifically described with reference to FIG. FIG. 2 is a block diagram showing the configuration inside and around the synchronization circuit unit 10 of the peripheral base station 2 according to the present embodiment. As shown in FIG. 2, the inside of the synchronization circuit unit 10 of the peripheral base station 2 of the present embodiment has a phase delay correction unit 11, a phase delay detection unit 12, a GPS reception unit 13, a GPS antenna 14, and a PLL. It is composed of a unit 15, a UW detection unit 16, a delay address generation unit 17, a write address generation unit 18, and an address addition unit 19.

Each part inside the synchronous circuit part 10 will be specifically described. The GPS receiver 13 includes a GPS antenna 14
Based on the GPS time signal received via the GPS, for example, a periodic pulse having a cycle of 1 second (hereinafter referred to as “GPS clock” or “G
(Referred to as “PSCLK”), and the PLL unit 15 described later is generated.
And the phase delay detector 12. The GPS clock is used by the central base station 1 and each peripheral base station 2
Since it is generated on the basis of the common GPS time signal in, the GPS clocks generated by the respective base stations may all be considered to be synchronized.

The PLL unit 15 includes a PLL (Phase-Locked L
oop) type signal oscillator, and an operation clock (hereinafter, “PLL clock” or “P”) of each unit in each peripheral base station 2.
LLCLK ") and a frame clock (eg 1.
875 seconds cycle).

More specifically, the PLL section 15 inputs the GPSCLK of 1 second cycle supplied from the GPS receiving section 13 to generate a clock of 1 / n second cycle, and the UW detecting section 16
And the delayed address generation unit 17 and the write address generation unit 18, and also generates a frame clock having a period of, for example, 1.875 seconds and supplies it to the delayed address generation unit 17. That is, the PLL unit 15 uses the GPSCLK
It is a clock generator that generates a clock with a shorter cycle. Here, n is a value determined by the accuracy of phase delay correction. Regarding the PLL method, "High-frequency measurement" by Hiroshi Yamamoto and Sumio Okawa, Corona Publishing Co., Ltd. 19
Published in September 1991, p232-p233.

The write address generation unit 18 generates a write address in the phase delay correction unit 11, which will be described later. Specifically, the PLL supplied from the PLL unit 15 is used.
The LK is counted, the write address is sequentially generated at the timing of the PLLCLK, and is output to the phase delay correction unit 11 and also to the address addition unit 19. Therefore,
A counter for counting PLLCLK is provided in the write address generation unit 18, and an address table corresponding to the count number is prepared, so that the write address is output based on the address table. Has become.

The UW detector 16 detects a unique word (hereinafter "U" included in the call signal transmitted from the central base station 1).
W)). Specifically, the signal transmitted from the central base station 1, temporarily stored in the phase delay correction unit 11, and read from the phase delay correction unit 11 is input. Then, PLLCLK supplied from the PLL unit 15
Check the ringing signal at the timing of
When W is detected, a UW detection pulse is output to the phase delay detector 12. Here, UW includes a synchronization code (synchronization signal).

The phase delay detector 12 transmits the ringing signal transmitted by the central base station 1 and received by the peripheral base stations 2 and G
The phase difference from PSCLK is detected, and the phase difference pulse indicating the phase difference is output to the delay address generation unit 17. Here, the phase difference pulse rises at the timing of the UW detection pulse received from the UW detection unit 16, and GP
A pulse falling at the timing of GPSCLK received from the S receiver 13 indicates the phase difference (phase delay) between the calling signal and GPSCLK to the delay address generator 17.

The delay address generator 17 receives the call signal and G
The phase difference from PSCLK is converted into an address on the phase delay correction unit 11 to generate a delay address. Specifically, the phase difference pulse output from the phase delay detection unit 12 is input, and the PLLCLK supplied from the PLL unit 15 is input.
Is used to count the width of the phase difference pulse, and the count value is converted into an address on the phase delay correction unit 11 to generate a delay address corresponding to the phase delay amount, which is output to the address addition unit 19. . Therefore, a counter for counting PLLCLK is provided in the delay address generation unit 17, and a conversion table for converting the count value into a delay address corresponding to the phase delay is provided.

The delay address generated here is 0.
(Zero) or a negative value, and the address addition unit 19
The read address obtained by adding the write address and the delayed address at is an address value that is the same as or smaller than the write address. That is, the read address is returned by adding 0 or a negative delay address to make the read address smaller than the write address, and the output of the calling signal is delayed by reading from the returned address position in accordance with PLLCLK. The delay time is the next GP
It is adjusted by the delay address in the delay address generator 17 so as to be synchronized with SCLK and set in the conversion table or the like.

The address adder 19 adds an address obtained by adding the write address output from the write address generator 18 and the delay address output from the delay address generator 17 to the phase delay corrector 11 It is output to the phase delay correction unit 11 as a read address in.

The phase delay correction unit 11 corrects the phase delay of the ringing signal transmitted from the central base station 1. In this embodiment, the phase delay correction unit 11 is a DPRAM capable of parallel input and output. (Dual Port RAM) is used. That is, the phase delay correction unit 11 inputs the symbol clock, the baseband signal including the calling signal transmitted from the central base station 1, and the binary / quaternary identification code, and generates the write address generation unit 18. The baseband signal is written from the LEFT side according to the written address, while the write address generated by the write address generation unit 18 and the delay address generated by the delay address generation unit 17 described later are added by the address addition unit. The signal is read from the RIGHT side according to the read address obtained by adding at 19, and is output to the transmitting unit 7. In addition, the written signal is read out immediately after writing, and the UW detection unit 16
It is also output to.

Here, the correction method in the phase delay correction unit 11 will be specifically described with reference to FIG. FIG.
Is the phase delay correction unit 11 of the peripheral base station 2 of the present embodiment.
4 is an explanatory diagram illustrating a correction method in FIG. In the phase delay correction unit 11 of the present embodiment, the input baseband signal is generated by the write address generation unit 18 regardless of whether or not there is a ringing signal transmitted from the central base station 1. Write in. Then, the data is read out at the same timing as the writing and output to the UW detector 16.

Then, the central base station 1 transmits the calling signal A, and as shown in FIG. 3, the calling signal A is written in the address (a + 2) of the phase delay correction section 11, and the address (a + 2) is read at the same timing. The calling signal A is read out and output to the UW detector 16. Then, the output signal is taken in by the UW detection unit 16, and the UW detection unit 16, the phase delay detection unit 12, and the delay address generation unit 17 work to provide a delay address corresponding to the phase difference between the calling signal and GPSCLK (in FIG. 3, for example, (“−2”) is generated, the reading is started from the read address (a in the example of FIG. 3) obtained by adding the write address and the delayed address, and the calling signal A is delayed and the calling signal A is transmitted. Will be output to.

Then, after that, a signal is read from the read address obtained by adding the delay address to the write address and transmitted, and, for example, the next call signal B is transmitted from the central base station 1, and FIG. As shown in, when the call signal B is written to the address (b + 2) of the phase delay correction unit 11, the delay address (-) is added to the write address (b + 2).
When the signal is read from the read address (b) obtained by adding 2) and then the signal is written to the write address (b + 4) of the phase delay correction unit 11, the calling signal is read from the read address (b + 2). B is read and output to the transmission unit 7.

By the above method, the writing and reading are shifted by the access time of the delay address, and the GPSCL
By delaying the reading so as to be synchronized with K, the calling signal is output to the transmitting unit 7 and transmitted at the timing synchronized with GPSCLK. As a result, each peripheral base station 2 simultaneously transmits a call signal at a timing synchronized with GPSCLK.

Next, an outline of the operation of the TDM synchronization system between mobile communication base stations in which the peripheral base stations of this embodiment are used will be described using FIG. 1 and FIG. In the TDM synchronization system between mobile communication base stations of the present embodiment, in each peripheral base station 2, when the power of the device is turned on, the phase delay correction unit 11 is on the B signal relay line connected to the central base station 1. Of the base band signal is written in the write address portion output from the write address generation unit 18, and simultaneously read out and the base band signal is output to the UW detection unit 16.

On the other hand, in the peripheral base station 2, the GPS circuit 20 periodically transmits the GPS time signal to the synchronizing circuit unit 10.
Is received by the GPS antenna 14 of the
Generate GPSCLK of 1 second cycle based on PS time,
It is supplied to the phase delay detection unit 12 and the PLL unit 15.
Then, in the PLL unit 15, based on GPSCLK supplied from the GPS receiving unit 13, a PLL of 1 / n second cycle
The LK is generated and supplied to the UW detection unit 16, the delay address generation unit 17, and the write address generation unit 18.

When the central base station 1 receives a calling signal for calling the receiver 5 from the network, GPSCL
Call signals are simultaneously transmitted to each peripheral base station 2 at a timing synchronized with K. Then, in each peripheral base station 2, the phase delay correction unit 11 of the synchronization circuit unit 10 receives and writes the transmitted ringing signal, and at the same time, reads it to read the UW detection unit 16.
Output to.

Then, the UW detector 16 takes in the ringing signal read and output by the phase delay corrector 11,
When the UW in the ringing signal is detected, the UW detection pulse is output to the phase delay detector 12. Furthermore, the phase delay detector 12
Then, when the UW detection pulse output from the UW detection unit 16 is detected, the phase difference pulse rises, and when the GPSCLK output from the GPS reception unit 13 is detected thereafter, the phase difference pulse falls.

At this time, the delay address generator 17 detects the phase difference pulse output from the phase delay detector 12,
The pulse width of the phase difference pulse is counted using PLLCLK supplied from the PLL unit 15, the count result is converted into an address in the phase delay correction unit 11, a delay address is generated, and output to the address addition unit 19. Then, in the address adder 19, the write address generator 1
Write address and delay address generator 1 output from 8
7 is added to the delay address output from the phase delay correction unit 1 as a read address in the phase delay correction unit 11.
Output to 1.

After that, the phase delay correction unit 11 writes the signal received from the central base station 1 at the write address position and reads the signal from the read address which is shifted from the write address by the delay address.

By the above operation, each peripheral base station 2
The manner in which the calling signal transmitted from the device is transmitted in synchronization with GPSCLK will be specifically described with reference to FIG. FIG.
T between mobile communication base stations using peripheral base stations of the present embodiment
It is a timing chart figure of the signal in each part of a DM synchronous system. TDM between mobile communication base stations according to the present embodiment
In the synchronization system, the central base station 1 and each peripheral base station 2 generate GPSCLK shown in FIG. 4A based on the GPS time received from the GPS satellite 20.
Further, in the peripheral base station 2, the PLL unit 15
PLLCLK having a cycle of 1 / n second shown in FIG. 4B is generated based on PSCLK.

When the central base station 1 receives the call signal from the network, as shown in FIG. 4 (c),
A call signal is transmitted to each peripheral base station 2 at the timing (time t0) of GPSCLK (A).

Then, in the peripheral base station 2, as shown in FIG. 4 (d), the phase delay correction unit 11 receives the call signal (writes in the DPRAM) after the phase delay occurs from time t0, and at the same time, the call signal is received. The data is read and output to the UW detector 16.

Then, in the UW detector 16, FIG.
As shown in, the UW is detected and the UW detection pulse is output at the time t1 after the phase delay time Δt from the time t0. Further, in the phase delay detecting section 12, as shown in FIG. 4 (f), the phase difference pulse is raised at time t1, and the GPSCLK
The phase difference pulse is made to fall at the timing (time t2) of (B). As a result, the pulse width of the phase difference pulse is (1-
Δt) seconds.

Then, the delay address generating section 17 determines the pulse width (1-Δt) seconds of the phase difference pulse as the phase delay correcting section 1.
By converting the address into 1 and changing the read address from the phase delay correction unit 11,
The ringing signal transmitted from the central base station 1 at the timing (time t0) of (A) changes to the peripheral base station 2 at time t1 after Δt.
Received and written by the phase delay correction unit 11 of
Time t2 (1-Δt) seconds after that, that is, GPSC
It is read and transmitted after the timing of LK (B) (FIG. 4 (g)).

After that, the ringing signal received after Δt from GPSCLK is transmitted in synchronization with the time (1-Δt) seconds after that, that is, the timing of GPSCLK (FIG. 4 (g)). .

As a result, even if the phase delay times Δt differ among the plurality of peripheral base stations 2, GPSCLK (A)
The phase delay is corrected in the timing section from (B) to (B), and thereafter, the ringing signals are simultaneously transmitted to the receiver 5 in synchronization with the timing of GPSCLK (synchronized state in FIG. 4).

According to the TDM synchronization system between mobile communication base stations using the peripheral base stations of this embodiment, the central base station 1
In each of the peripheral base stations 2 that have received the calling signal transmitted from, the phase delay detection unit 12 detects the phase difference (phase delay) from the calling signal to GPSCLK, and the delay address generation unit 17 further detects the detected phase difference. The call signal is delayed by converting the address of the phase delay correction unit 11 to generate a delay address corresponding to the phase delay, and reading the read address that is shifted from the write address by the delay address in the phase delay correction unit 11 to delay the call signal. Since the signal is transmitted to the receiver 5 in synchronism with each other, all of the plurality of peripheral base stations 2 simultaneously transmit the call signal in synchronism with GPSCLK, and the synchronization can be achieved in a short time. effective.

Further, the T between mobile communication base stations of this embodiment is
In the DM synchronization system, since GPS time that can be recognized as a common time by each device is used as a time for synchronization, there is an effect that highly accurate synchronization can be realized.

[0055]

According to the first and second aspects of the invention, the GPS generated based on the received call signal and GPS time.
A delay address corresponding to the phase delay with the clock is generated by the delay address generation unit, and when reading of the delay address is completed, the read address becomes equal to the write address where the call signal was written in the storage unit, and the phase delay is corrected. Since the phase delay correction unit outputs the calling signal from the read address to the transmitting unit and the peripheral base station and the synchronizing method therefor, the phase delay is corrected after receiving the calling signal, and the next GPS clock is set. In synchronization, each peripheral base station can transmit the call signal to the receiver all at once, and there is an effect that the synchronization of the call signal transmitted from each peripheral base station can be quickly established.

[Brief description of drawings]

FIG. 1 is a diagram illustrating an inter-mobile communication base station T according to an embodiment of the present invention.
It is a schematic block diagram of a DM synchronization system.

FIG. 2 is a block diagram showing a configuration inside and around a synchronization circuit unit of a peripheral base station according to the present embodiment.

FIG. 3 is an explanatory diagram illustrating a correction method in a phase delay correction unit of a peripheral base station according to the present embodiment.

FIG. 4 is a timing chart diagram of signals in each unit of the TDM synchronization system between mobile communication base stations using the peripheral base stations of the present embodiment.

FIG. 5 is a schematic configuration diagram of a conventional conventional TDM synchronization system between mobile communication base stations.

FIG. 6 is a timing chart showing a conventional TDM synchronization method between mobile communication base stations.

[Explanation of symbols]

1, 1 '... Central base station, 2, 2' ... Peripheral base station, 3
... Phase correction antenna, 4 ... Peripheral base station antenna,
5 ... Receiver, 6 ... Phase corrector, 7 ... Transmitter, 1
0 ... Synchronous circuit section, 11 ... Phase delay correcting section, 12 ... Phase delay detecting section, 13 ... GPS receiving section, 14 ... GPS antenna, 15 ... PLL section, 16 ... UW detecting section, 1
7 ... Delayed address generation unit, 18 ... Write address generation unit, 19 ... Address addition unit, 20 ... GPS satellite

Claims (2)

[Claims] 1. A peripheral base station which receives a ringing signal transmitted from a central base station and transmits it to a portable device receives GPS time from a GPS satellite using satellite communication,
A receiver for generating a GPS clock based on PS time,
A unique word detection unit that detects a unique word of the calling signal and outputs a detection signal, a phase delay detection unit that detects a phase delay from the generation of the detection signal to the generation of the next GPS clock, and the detected phase A delay address generation unit that generates a delay address corresponding to a phase delay based on the delay, a clock generation unit that generates a clock with a shorter cycle from the GPS clock, and a write address by counting the clock with the shorter cycle. A write address generation unit that generates a read address by adding the generated delay address to the generated write address, and a storage unit that stores the received call signal. , Write to the position of the storage section indicated by the write address, and read out from the position of the storage section indicated by the read address and output. Neighboring base station, characterized in that it comprises a phase delay correcting unit, and a transmission unit for transmitting a call signal output from the phase delay correcting section that. 2. A write address generation unit counts clocks output from the clock generation unit to generate a write address, outputs the write address to a phase delay correction unit, and outputs the write address to an address addition unit. Input the delay address generated by the delay address generation unit according to the phase delay detected by the phase delay detection unit, add it to the write address and output it as the read address to the phase delay correction unit, The delay correction unit writes a calling signal to the storage unit according to the write address, reads from the read address of the storage unit, and when the read of the delay address corresponding to the phase delay is completed, the read address is written to the write address. Equal to the embedded address, and the phase delay correction unit
2. The synchronization method in a peripheral base station according to claim 1, wherein the calling signal is output to the transmitting unit from the position of the storage unit indicated by the read address.