JPH01215134A - Synchronizing burst transmission phase control system for ss-tdma satellite communication - Google Patents

Abstract

PURPOSE:To obtain optimum synchronizing accuracy by selecting a metric pattern included in a synchronizing burst so as to be optimum to the operating characteristic of a demodulator. CONSTITUTION:A burst signal of the same constitution and same content (demodulator supervising burst) as the synchronizing burst is generated to a position different from a TDMA frame synchronizing burst in addition to the synchronizing burst sent actually from a satellite communication reference station to the communication satellite. Then the supervising burst is reflected in an IF level in the satellite communication reference station without sending the supervising burst toward the communication satellite and the gate is reset by a window generated by using the TDMA frame in the satellite communication reference station as the base. Then the burst is combined with the synchronizing burst returned actually from the communication satellite and inputted to the demodulator to detect the supervising burst after demodulation thereby supervising the operating characteristic of the demodulator normally. Thus, the metric pattern included in the synchronizing burst is selected to obtain the maximum synchronizing accuracy in response to the operating characteristic of the demodulator.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a synchronous burst transmission phase and phase control system, and in particular to SS-TDMA (Satel!) via a communication satellite.
ite Switched-Time Divisio
n Multiple^ccess: T between multiple earth stations that communicate using the satellite-switched time-division multiple access) method.
The present invention relates to a synchronous burst transmission phase control scheme for establishing and maintaining DMA frames.

(Prior Art) Recently, SS-TD is one of the satellite communication systems formed between multiple earth stations using large-capacity communication satellites.
The MA system is expected to be the future form of satellite communication system. First, SS-TDMA will be briefly explained using figures.

Figure 3 is a principle diagram of the SS-TDMA system. In Figure 9, which shows the structure of the repeater inside the communication satellite and the relationship between the corresponding earth station, 300 is a spot on board the communication satellite. A beam antenna is shown, and as an example, a case is shown in which four antennas are used for transmitting and receiving. Each antenna generates a narrow spot beam 301 that illuminates a limited spot area 302 (A, B, C, and D) on the ground.

Conversely, each antenna has a spot area 302A.

Radio waves radiated from earth stations 303 located at B, C, and D are received respectively.

The SS-TDMA method uses spot beams to increase the gain of the satellite antenna and significantly increase the effective radiated power, and by using the same frequency for well-separated spot areas, A major feature is that an ideal communication system can be constructed in terms of reuse.

The route from the earth station to the satellite is called uplink, and the reverse is called downlink, but there is also a combination in which the antenna 300 is made independent for uplink and downlink, and the - side has a narrow spot beam and the other side has a wide beam. It is possible.

Here, for the sake of simplicity, the explanation will be continued using the configuration shown in FIG. 3 as an example.

Although only one earth station is shown in each spot area 302 in the figure, each area may actually include multiple earth stations. Each spot area 302A,
The radio waves radiated from the earth stations 303 in B, C, and D are received by the corresponding antennas 300, and are sent to the RA,
R.B., R.C.

It is amplified by receiver 304, shown as RD.

On the other hand, each spot area 302A, B from the antenna 300
, C, and D are TA and TB.

They are supplied from transmitters 305 shown as TC and TD, respectively.

A matrix switch 306 is provided to connect the uplink and downlink, and is controlled by a matrix switch control circuit 307.

The function of a matrix switch is determined by a connection mode that indicates the combination of which uplink and which downlink are connected, and by switching between several connection modes according to a specified time schedule, any uplink and downlink can be connected. The links will be periodically connected.

Among these connection modes, there is also a broadcast mode in which -m one uplink signal is connected to all downlinks. Table 1 shows examples of connection mode combinations.

The table shows five connection modes: 1. Il, 1. A) shows the case in which fV and V are periodically repeated. A) shows which region the signals from each region are connected to the downlink corresponding to from the perspective of uplink receivers RA, RB, RC, and RD. From a different perspective, it shows the downlink transmitters TA and TB.

From the perspective of TC and TD, it shows which area the signals to be radiated to each area are supplied from the corresponding uplink.

Therefore, each region is connected periodically and intermittently. The communication method carried out via such communication satellites is limited to TDMA, that is, the time division multiple access method, and the repetition period of the above-mentioned connection mode Table 1 corresponds to the frame period of TDMA.

First of all, in the TDMA communication system, one of the participating earth stations acts as a reference station, and the reference station transmits a signal called a reference burst at the TDMA frame period according to its own timing standard, and each participating station receives this signal. Establish timing standards.

However, in the case of SS-TDMA, the above-mentioned connection mode switching is performed by the matrix switch control circuit 3 shown in FIG.
Since this is done according to the timing reference built into the 07, the reference station must first synchronize its own timing reference with the timing reference on the satellite. Of course, the distance between the satellite and the reference station changes from time to time even when using a geostationary satellite, so the above meaning of "synchronization" means that the reference station transmits the signal according to its own timing standard. On a satellite, it means controlling the own timing reference so that it is synchronized with the satellite's timing reference.

As a countermeasure for this, TDM in SS-TDMA system
A synchronous burst transmission phase control method has been considered as a means for establishing and maintaining an A frame. Among the connection modes shown in Table 1, in order for the reference station to synchronize its own timing reference with the satellite's timing reference, the reference station uses a connection mode in which the synchronization burst transmitted by the own station can be received within the area of the own station. .

FIG. 4 is a conceptual system diagram showing only the relevant main parts in the conventional system. In FIG. 4, the reference station on earth includes a synchronous burst generating means 500, a modulation transmission system 501,
A reception demodulation system 502, a phase error detection means 503, and a metric pattern phase control means 504 are provided, and a gate means 506 is provided inside the communication satellite 505. Further, in the figure, 507 indicates an uplink propagation path, and 508 indicates a downlink propagation path.

In FIG. 4, from the synchronous burst generating means 500,
A predetermined synchronized burst signal generated based on the reference time signal in the reference station is output, and the modulation transmission system 501,
and is input to gate means 506 via uplink propagation path 507. In the gating means 506, the synchronized burst signal is gated by a synchronization window generated and input based on the reference time signal in the communication satellite, and is sent back to the reference station via the downlink propagation path 508. Ru.

The synchronized burst signal is a commonly used PSK (Phase 5) signal, as shown in FIG.
Corresponding to the case where a shift keying modulation method or the like is applied as a modulation method to a carrier wave, an unmodulated carrier wave portion (Continuous
Wave (abbreviated as CW) and a predetermined code time series signal (BHTiming) that acts for clock pulse extraction.
Recovery: abbreviated as BTR), and then a predetermined sync signal (Unique Word: UW
(abbreviated as ), and the part that is modulated by
A metric pattern (M
Etric Pattern: METRIC
The modulation part by (abbreviated as ) continues.

When the synchronous burst transmission phase control method is in a normal operating state, as described above, the downlink propagation path 5
The synchronization burst signal returned to the predetermined reference station via the communication satellite , the latter half of the metric pattern is input to the reception demodulation system 502 in a gated-off form. This synchronized burst signal is demodulated in the reception demodulation system 502 through a two-phase, four-phase, or polyphase PSK phase demodulation operation, and is converted into a unique word (UW) as shown by a solid line in FIG. 5(c). and the second half at time position 601
A metric pattern (MET
RIC), a synchronization burst signal is generated and sent to the phase error detection means 503. , the metric pattern (ME
TRIC), gated-off trailing edge time position 60
1 is detected by measuring the length of a correctly received symbol according to the transmitted code string in the code string of the metric pattern (METRIC), and the normal metric pattern (M
The time difference from the reference time position which is set at the center time position of ETRIC and which is abbreviated by the reference symbol length is extracted and output as a phase error signal in the synchronous burst transmission phase control method. This phase error signal is sent to the synchronization burst generation means 500 via the metric pattern phase control means 504, and controls the phase of the synchronization burst generated in the synchronization burst generation means 500. The subsequent operation is as described above, and the phase error signal output from the phase error detection means 503 is made to be zero by the synchronous burst transmission phase control method formed by the closed loop shown in FIG. , the phase of the synchronization burst signals is controlled and adjusted to establish and maintain a TDMA frame synchronized to a synchronization window within the communication satellite. Note that as a phase control method in the synchronous burst generating means 500, for example, a voltage controlled oscillator may be used, or a frequency divider may be used.

Regarding the specific contents of the above-mentioned synchronous burst transmission phase control method, see the documents R, A, RAPUANO, AND N,
SII-IMASAKI, “5YNCIIRONIZA
TION OF EARTII 5TATIONSTO
SA place LITE-5WITCHED 5EQUENCE
S,” AIAA 4THCOMMUNICATION
S SA location LITE SYSTEMS C0NFERE
N.C.E.

AI'RIL 1972. As detailed in , the time position 601 of the trailing edge of gate-off in the measurement metric pattern (METRIC) is correctly received according to the transmitted code string (METRIC).
When detecting by measuring the symbol length of
Signal-to-noise ratio and synchronization window trailing edge 600 (fifth
The metric pattern (M
l! TRIC) produces an uncertain time region at the time position of the trailing edge.

If the second half of the metric pattern (METRIC) is lost due to the synchronization window, the demodulator output will ideally be a random pattern, and typically 000... or 111... depending on the demodulator tuning state. Patterns such as... appear. Therefore, it is necessary to use a pattern that can be easily distinguished from the above-described pattern as the specific pattern of the metric area.

Usually, this metric pattern is uniquely selected through experiments or the like. In order to eliminate the position uncertainty in determining the time position of the trailing edge of the synchronization window 600 (FIG. 5(b)) by measuring the symbol length of the metric pattern that is correctly received according to the transmitted code string, A predetermined metric pattern constituting a part of a burst signal is accumulated for a predetermined number of measurements n, and compared and matched with the predetermined metric pattern for each symbol, and the results of this comparison and matching are simply integrated for each symbol. Alternatively, the symbol of the correctly received metric pattern can be determined by converting it into a predetermined weighting coefficient that corrects the error occurrence characteristics of the transmission path, integrating it, and comparing and checking the integrated value for each symbol with a predetermined reference level value. A method is used to find the length.

(Problem to be Solved by the Invention) In the conventional method described above, since the metric pattern during the synchronization burst is uniquely selected, there is a drawback that the metric pattern may not be optimal depending on the adjustment state of the demodulator. . In particular, in equipment that requires particularly high reliability, such as a reference station in the SS-TDMA satellite communication system, it is common to have a duplex configuration, in which case the demodulator in each equipment It is difficult to imagine that the adjustment state is the same, and even if the demodulator is replaced for maintenance, there is no guarantee that the adjustment state will be set optimally for the metric pattern being used, and it may not be possible to In order to use the SS-TDMA satellite communication system, there is a serious drawback that a mechanism is required to reduce the suitability of the metric pattern due to external factors such as the adjustment state of the demodulator. This was the biggest technical problem to be faced.

SUMMARY OF THE INVENTION In view of the problems of the prior art described above, an object of the present invention is to
ate Frequency: IF) A metric pattern that constantly monitors the operating characteristics of the demodulator using the burst signal folded back at the signal stage and achieves the highest synchronization accuracy according to the operating characteristics of the demodulator at that time. The purpose of the present invention is to provide a synchronous burst transmission phase control method for selecting synchronous burst transmission.

(Means for Solving the Problems) The present invention has the following means configuration to achieve the above object.

That is, the synchronous burst transmission phase control method for SS-TDMA satellite communication of the present invention includes a plurality of spot beams in one or both of the uplink and downlink, and the connection between the uplink and downlink is controlled by a satellite switch. The connection mode is switched sequentially according to the connection mode determined in advance by A predetermined satellite communication reference station that establishes and maintains a TDMA frame between earth stations in a plurality of different spot areas in a satellite communication system based on the SS-TDMA system configured with an earth station of
T transmitted based on a period corresponding to a frame and generated based on a predetermined reference time within the communication satellite.
Receives and detects a predetermined synchronization burst that is gated off and returned by a synchronization window for DMA frame regulation, and controls the sending reference time of the synchronization burst so that the detection state of the synchronization burst is constantly in the predetermined state. By doing so, the TDMA frames between earth stations in a plurality of different spot areas are
In a synchronization burst transmission phase control method synchronized with a DMA frame; in addition to the synchronization burst sent from a satellite communication reference station toward a communication satellite, a synchronization burst having the same configuration as the synchronization burst is placed at a time position different from the synchronization burst in the TDMA frame. , means for generating burst signals with the same content; and after the burst signal is looped back at an intermediate frequency signal stage within a satellite communication reference station and gated off by a window generated based on a TDMA frame within the satellite communication reference station, the burst signal is sent to the satellite communication reference station. means for inputting the demodulator into a demodulator; means for detecting the burst signal after demodulation and constantly monitoring operating characteristics of the demodulator; The present invention is characterized by comprising means for selecting an optimum demodulator according to the operating characteristics of the demodulator.

(for production) Hereinafter, the present invention having the above-mentioned means will be explained in detail.

With the above means configuration, the present invention provides, in addition to the synchronization burst actually transmitted from the satellite communication reference station to the communication satellite, a synchronization burst at a position different from the synchronization burst in the TDMA frame.
Generates a burst signal (hereinafter referred to as a (demodulator) monitoring burst) with the same configuration and content as the synchronous burst,
Without sending the monitoring burst toward the communication satellite, it is looped back at the IF level within the satellite communication reference station, gated off by a window generated based on the TDMA frame within the satellite communication reference station, and then sent from the communication satellite. In order to detect the demodulated monitoring burst by inputting it to the demodulator in combination with the synchronization burst system that is actually sent back, in particular, the pattern state of the metric pattern within the monitoring burst after being gated off in the window), the steady state The operating characteristics of the demodulator (especially the demodulation pattern characteristics when no signal is input) are monitored, and the metric pattern included in the synchronization burst is selected to obtain the highest synchronization accuracy according to the operating characteristics of the demodulator. do.

(Example) Next, an example of the present invention will be described with reference to the drawings.

FIG. 1 shows a functional block diagram of a synchronization control unit in a satellite communication reference station as an embodiment of the present invention. A transmission frame counter 100 uses a system clock 1 as a clock input to count TDMA frames, It has a function of using phase correction information 15 output from the detection circuit 108 to synchronize the TDMA frame with the TDMA frame defined within the communication satellite.

Further, based on the TDMA frame generated by itself, the transmission frame counter 100 sends a synchronization burst/monitoring burst generation timing signal 2 to the synchronization burst/monitoring burst generation circuit 101, and sends a synchronization burst/monitoring burst generation timing signal 2 to the transmission IF multiplication signal switching circuit 103. It outputs the transmission IF multiplied signal switching timing signal 5 and the monitoring burst window generation timing signal 8 to the monitoring burst window generation circuit 104. A synchronous burst/monitoring burst generation circuit 101 generates each burst signal of a synchronous burst and a monitoring burst using a synchronous burst/monitoring burst generation timing signal 2 as a start signal, and outputs each burst signal as a transmission synchronous burst/monitoring burst signal 3 to a modulator 102. supply to At this time, the metric pattern information signal 19 selected by the metric pattern selection selector 110 is inserted into the metric pattern section of the synchronization burst/monitoring burst to generate each burst signal. The modulator 102 inputs the transmission synchronization burst/monitoring burst signal 3 which is a baseband signal, and after modulating it, supplies it to the transmission IF multiplication signal switching circuit 103 as a transmission synchronization burst/monitoring burst IF signal 4 which is an IF multiplied signal. do.

The transmission IF multiplication signal switching circuit 103 converts the input transmission synchronous burst/monitoring burst IF signal 4 into a transmission synchronous burst signal 6 and a transmission monitoring burst IF signal 7 based on the transmission IF multiplication signal switching timing signal 5. Divide into. The transmission synchronous burst signal signal 6 divided here is as follows:
The satellite communication standard station's up converter, RF (R
adi.

The transmission monitoring burst signal signal 7 is input to the 1F signal gate circuit 105. With this operation, only the synchronization burst is sent to the actual communication satellite, and the monitoring burst is not output to the outside.

The IF signal gate circuit 105 converts the input transmission monitoring burst IF signal 7 into a monitoring burst window signal 9 generated by the monitoring burst window generation circuit 104 using the monitoring burst window generation timing signal 8 as a start signal. gating
L, the reception monitoring burst signal is outputted to the reception IF signal switching circuit 106 as the signal 10. The reception IF signal switching circuit 106 switches between the reception monitoring burst signal signal 10 and the reception synchronization burst signal signal 11, which is gated off in the communication satellite and sent back, and whose frequency is converted by the RF device and down converter of the satellite communication reference station. Enter and receive IF
Based on the signal switching timing signal 12, it is synthesized as a reception synchronization burst/monitoring burst IF signal 13 and output to the demodulator 107. The demodulator 107 inputs the reception synchronization burst/monitoring burst IP signal 13 which is an IF multiplied signal, demodulates it, and outputs it as a reception synchronization burst/monitoring burst signal 14 which is a baseband signal.

The position error detection circuit 108 compares the metric pattern of the synchronization burst portion of the received synchronization burst/monitoring burst signal 14 with the metric pattern information signal 19 to determine whether the TDMA frame at the satellite communication reference station is defined within the communication satellite. The positional error between the transmission frame counter 100 and the TDMA frame is detected, and the detected information is supplied as phase correction information 15 to correct the counting operation of the transmission frame counter 100. The demodulator operating characteristic monitoring circuit 109 determines the operating characteristics of the demodulator 107 at that point in time by monitoring the metric pattern of the monitoring burst part of the received synchronization burst/monitoring burst signal 14, and determines the optimum operating characteristic at that point. Metric pattern selection information 16 for selecting a metric pattern is output to the metric pattern selection selector 110. Based on the metric pattern selection information 16, the metric pattern selection selector 110 outputs the optimal one of the predetermined metric pattern 1 information 17 and the metric pattern 2 information 18 at that time as the metric pattern information signal 19. Here, although it is possible to prepare a plurality of pieces of predetermined metric pattern information, here, in order to make the explanation clear, two types are used.

FIG. 2 is an example of a time chart showing typical time relationships of the main signals in the functional block diagram shown in FIG. 1. However, in Fig. 2, the time relationship between the signal on the synchronous burst transmitting side and the signal on the synchronous burst receiving side ignores the propagation delay time due to the synchronous burst via the communication satellite for clarity of explanation. There is.

Next, the operation of this embodiment will be explained with reference to FIGS. 1 and 2. The transmission and reception of synchronization bursts, the detection of position errors, etc. are the same as those in the conventional example, so they are omitted here.
The operation of reception and processing will be explained.

The supervisory burst (FIG. 2, 4), which has the same burst configuration as the synchronous burst, contains the same content, and is generated via the same route, is processed by the transmission IF defect signal switching circuit 103 into the supervisory burst single system (transmission supervisory A supervisory burst window signal 9 (FIG. 2, 9) generated by the supervisory burst window generation circuit 104 in response to this transmission supervisory burst IF signal 7 is separated as a burst IF signal 7) (FIG. 2, 7). is applied in the IF signal gating circuit 105 to gate off a portion of the metric pattern within the monitoring burst (FIG. 2, 10). However, in this case, unlike gate-off in a communication satellite, both the generation timing of the supervisory burst and the generation timing of the window signal 9 for supervisory burst are based on the output of the transmission frame counter 100, so the supervisory burst is It will always be gated off at a certain timing.

After being gated off, the monitoring burst is combined with the synchronization burst system (reception synchronization burst IF signal 11 (FIG. 2 11)) gated off and returned within the communication satellite by the reception IF signal switching circuit 106, Synchronous burst/monitoring burst IF signal 13 (Fig. 2 1
3) is supplied to the demodulator 107. The demodulator operating characteristic monitoring circuit 109 inputs the metric pattern of the monitoring burst part of the signal demodulated as the baseband signal (reception synchronization burst/monitoring burst signal 14) by the demodulator 107, and inputs the metric pattern of the monitoring burst part in the metric pattern. The state of the pattern after being gated off by the window signal 9 is monitored. As a result of this monitoring, demodulator 10
7. Reception synchronization burst/monitoring burst I when no signal is input
The demodulation characteristics of the F signal 13 can be determined, and it is expected that the demodulation characteristics will be applied to the metric pattern of the synchronous burst portion. As a result, the demodulator 10 at that point
The optimal metric pattern for the characteristics of No. 7 can be selected, and that metric pattern is also applied to the synchronization burst to obtain the optimal synchronization accuracy at that time.

(Effects of the Invention) As explained above, the present invention can change the metric pattern included in the synchronization burst according to the operating characteristics of the demodulator.
By selecting the optimum one, it is possible to eliminate the unsuitability of the metric pattern due to the adjustment state of the demodulator, which is the main factor in the operating characteristics of the demodulator, and achieve the optimum synchronization accuracy at that point. Metric pattern i! ! There are effects that you can choose from. In particular, by quantitatively monitoring the operating characteristics of the demodulator, the optimal metric pattern is always selected, so optimal synchronization accuracy can be achieved even when switching duplication or replacing the demodulator during maintenance. It has a sustainable effect.

[Brief explanation of the drawing]

FIG. 1 is a functional block diagram of a synchronization control unit in a satellite communication reference station that is an embodiment of the synchronous burst transmission phase control method for SS-TDMA@star communications of the present invention, and FIG. 2 is a functional block diagram of the functional block diagram shown in FIG. 1. A time chart showing an example of a typical time relationship between the main signals of (ignoring the propagation delay time via communication satellite), Figure 3 shows S
The principle diagram of the S-TDMA system, Figure 4, is a system conceptual diagram of the conventional synchronous burst transmission phase control system, Figure 5 (a).
is a waveform conceptual diagram of a synchronization burst at the time of transmission, FIG. 1...System clock, 2...Synchronization burst/monitoring burst generation timing signal, 3...
...Transmission synchronous burst/monitoring burst signal, 4...
...Transmission synchronous burst/monitoring burst IF signal, 5
...Transmission IF signal switching timing signal, 6
...Transmission synchronous burst IF signal, 7...
...Transmission monitoring burst IP signal, 8...Window generation timing signal for monitoring burst, 9...
...Window signal for monitoring burst, 10...
...Reception monitoring burst IF signal, 11...Reception synchronous burst IF signal, 12...Reception IF
Signal switching timing signal, 13... Reception synchronization burst/monitoring burst IF signal, 14...
・・Reception synchronization burst/monitoring burst signal, 15・
... Phase correction information, 16 ... Metric pattern selection information, 17 ... Metric pattern 1 information, 18 ... Metric pattern 2
information, 19... metric pattern information signal, 100... transmission frame counter,
101...Synchronization burst/monitoring burst generation circuit, 102...Modulator, 103...
・Transmission IF signal switching circuit, 104... Monitor burst window generation circuit, 105...
・IF signal gate circuit, 106... Reception IP
Double signal switching circuit, 107...Demodulator, 1
08...Position error detection circuit, 109...
...Demodulator operating characteristic monitoring circuit, 110...
Selector for metric pattern selection, 300...
... Spot beam antenna, 301 ... Spot beam, 302 ... Spot area,
303...Earth station, 304...Receiver, 305...Transmitter, 306...
- Matrix switch, 307... Matrix switch control circuit, 500... Synchronous burst generating means, 501... Modulation transmission system, 50
2... Reception demodulation system, 503... Phase error detection means, 504... metric pattern phase control means, 505... Communication satellite, 50
6... Gate means, 507... Uplink propagation path, 508... Downlink propagation path, 600... Trailing edge of synchronization window,
・601...Time position. Agent: Yoshihiro Yahata, patent attorney TDMA7u-A. ) Chi/r Kugo 1ri d Shin 8/l kita kami Ukekima 90 building wo j (Itiming each - to 03 child J hanging 2 fig.

Claims (1)

[Claims] One or both of the uplink and downlink includes a plurality of spot beams, and the connection between the uplink and downlink is sequentially switched according to a predetermined connection mode by a satellite switch, and this is performed according to timing standards on the satellite. A plurality of different spots in a satellite communication system using the SS-TDMA system, which is composed of a communication satellite that has a function that repeats at a constant frame period and a plurality of earth stations that perform communication using a time division multiple access method via this communication satellite. At a predetermined satellite communication reference station that establishes and maintains a TDMA frame between earth stations within a region, the TDMA frame is transmitted to the communication satellite based on a period corresponding to the TDMA frame, and is based on a predetermined reference time within the communication satellite. Receives and detects a predetermined synchronization burst that is gated off and returned by a synchronization window for TDMA frame regulations generated as a TDMA frame, and transmits the synchronization burst so that the detection state of the synchronization burst is constantly in a predetermined state. In a synchronized burst transmission phase control method that synchronizes TDMA frames between earth stations in a plurality of different spot areas with a TDMA frame defined within the communication satellite by controlling a reference time; communication from a satellite communication reference station. means for generating, in addition to the synchronization burst to be transmitted toward the satellite, a burst signal having the same configuration and content as the synchronization burst at a time position different from the synchronization burst in the TDMA frame; means for inputting the demodulated burst signal to a demodulator in the satellite communication reference station after being looped back at the intermediate frequency signal stage in the reference station and gated off by a window generated based on a TDMA frame in the satellite communication reference station; means for constantly monitoring the operating characteristics of the demodulator; means for selecting an optimum metric pattern included in the synchronization burst according to the operating characteristics of the demodulator obtained by the monitoring means; A synchronous burst transmission phase control system for SS-TDMA satellite communication, characterized by comprising: