JPS6016737A - Time division multiplex access device - Google Patents

Abstract

PURPOSE:To make a synchronizing operation easy and also to attain time division multiplex access to analog information by dividing equally a time axis to produce a location of a synchronizing signal of each station and giving an index to the synchronization. CONSTITUTION:A synchronizing signal 7 and as required, an information signal 8 are transmitted from a reference station 2. Its time band 9 has the time length identical to that of a time band 10 for other transmission station 3 and they are relayed by a transponder mounted on an artificial satellite 1. The transmission station 3 receives a signal transmitted from the reference station 2, extracts only its synchronizing signal and forms a reference synchronizing signal location through multiplication by 2. A signal 11 represents the start point of a signal transmitted from the transmission station 3. In order to accommodate the information signal transmitted from the transmission station 3 to a prescribed location, the synchronizing signal 12 is transmitted at first nearly at the middle of the time band 10 and matched to a reference synchronizing signal 11 for the own station.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Section'Mf) The present invention relates to a device for common use of one transponder by a plurality of earth stations through simple time division multiplex access.

(Background technology) In contrast to the conventional digital iris code, ゛C was developed.
In H-division multiple access (so-called 'I''l) MA), the reference burst is transmitted from the reference station, and the other transmitting stations receive the reference burst and then transmit the transmitted burst. Adjust the sending time to J, 5, when the burst is at a time position that is a certain time away from the reference burst.This method is (support)
From each station, change the transmit burst length and position to A.
zru, (a) No. f゛ station information can be notified to each station, etc. (11 points), but (a1 equipment configuration is complicated (determining the predetermined burst position) (1)) Time axis compression/time division multiplexing'(TCM;
time co+nplcssion muff-
iplex) analog signal such as a video signal (the time axis of the video signal is compressed and other video signals are placed on the free time axis, and the signal itself is an analog signal) For the modulation and demodulation method θ, the affinity or bad U, etc. O)
There are drawbacks.

(Problems to be solved by the invention) In order to eliminate these drawbacks, the present invention is characterized in that the time axis is equally divided, the synchronization signal position of each station is easily generated, and the synchronization is indexed. [First, it simplifies the device configuration, makes it easier to perform synchronization, and allows multiple accesses to analog information more often than not. 1σ) The goal is to make effective use of transponders.

(Structure and operation of the invention) Fig. 1 shows a satellite communication system according to the present invention 0) 1, in which 1 is an artificial satellite, 2 is a reference transmitting station, 3 is another transmitting station, and 4 + 5 is a receiving station. (3 is a ground station for line control, which is installed as necessary.) From the reference station 2, as shown in Fig. 2, a synchronization signal 7 and an information signal 8 are sent as necessary. The time period 9 is the same time length as the time period 0 for the other transmitting station 3, and both are relayed by one transponder carried on the satellite 1. .

In step 3, the signal sent from the reference station is received, only its synchronization signal is extracted (Fig. 3), and it is multiplied by 2 to obtain the reference synchronization signal position (Fig. 4). Signal 11 or 3 indicates the starting point of the signal to be sent.

In order for the information signal sent from 3 to be stored at the predetermined position in FIG. Adjust to the reference synchronization signal 11. FIG. 6 shows the principle of a device for this purpose, where l:3 is a variable delay generator, 14 is a reference signal 1
1 and the synchronization signal I2, 15 is a time length 31'('
16 is a gate output, and 17 is a feedback line from 16 to 1. The operation for each f4B minute is shown in FIG. When the synchronization signal J2 does not match the reference signal 11, the phase of both signals is output as the gate output 4), so the output is thicker than the output level 18 of a single pulse. When the two touch each other, the maximum output level is 19, and when they completely match 1-20, it becomes equal to level 18.

The delay amount of the variable delay generator 13 is adjusted so that the gate output coincides with 2°.

Furthermore, since the received waveform of the transmitting station 3 at the initial acquisition stage is as shown in FIG. 5, the synchronization signal 12 becomes an obstacle in obtaining the reference signal (FIG. 3). Therefore, it is sufficient to make the amplitude of 12+7J smaller than the clamp level of the reference signal.

However, since the phase matches the addition point in Fig. 7, the synchronization signal will be the information sent from the transmitting station 3 and will be the time reference, so it is necessary to have the same level as the base and signal 7. There is. In addition, the level I5I is the phase of (I) 11 and 12, so it is the amplitude of 12 or close to the amplitude of 11.
The drop to 20 becomes clear.

Takumi') 辷、believe 12 almost matches 11 and ℃・ro state (
1 to 19' in FIG. 7, it is easier to perform automatic phase control if the amplitudes are kept the same.

FIG. 8 shows a configuration example of the present invention in a satellite communication earth station. 21
2 is an antenna, 22 is a clamper, 23 is a multiplier, 2I is a monitor, 25 is a synchronizing signal pulse generator, and is a semi-fixed delay generator. 2] is received by the transmitter/receiver duplexer (T/1(,
), a low-noise amplifier (LNA), and a demodulator (1), the received signal (Fig. 5) is extracted by a clamper 22 to extract one synchronized signal of the reference transmitting station, and then multiplied by a multiplier 23. Generate the reference synchronization signal position (Fig. 4).

Also, the other output of the D ladder 4 enters the combiner 14 as it is,
It enters the gate 15 at the same time as the reference synchronization signal 48, outputs only the time near the reference synchronization signal of its own station, and performs the comparison operation shown in FIG. On the other hand, from 25, the frequency is reference transmitting station 2.
An instruction pulse equal to the reference synchronization signal from the station is generated, and the initial phase and propagation delay of 25 and the time difference to the time slot assigned to the own station are compensated by 26.

Then, in step 13, phase matching is performed.

When transmitting a video signal subjected to time axis compression and time division multiplexing (T(31)) according to the present invention, the horizontal synchronization signal S or the vertical synchronization signal is used as the synchronization signal 12 of the present invention.
Toka-(]kiro(/, -tashi, video method (from 閞 41-anti-1 tNj/-ri, waveform deformation l:= v-a
0:y, 11-j' 1. j j 2 and; 3 or the same T (' If you send 1 e-tetsu signal to (511, Ji Ding 7), it becomes mini (j field mark r 1st place is ゛Multi-vehicle access - East I,) shi. l , -6 (on f, 2 stations or 1) - We have explained the case where the transponder f is "1" and 3 stations or more -1-
The same principle and configuration can be applied to multiple accesses. (-1) Allocate a space between the 5"IRI's for each transmitting station other than the reference station, or at the same time, set the 11. 7.).

Also, the transmission time length of each transmitting station must be the same (,1,
There is no synchronization (the frame narrowed by the m number is placed in the 71st position), and multiple frames may be allocated to one station.

Also, regarding the length of the opening time of the gate 15 (see Fig. 7 above), it is about three times the time width of the phase signal and a variable delay (/l).
L delay 1: (If the control is performed only between 19 and 19', it may be twice as long. Furthermore, (e)i only near (t) 20
It is preferable that l be at least longer than the time width of the synchronization signal.

(Effect of the invention) The above explanation V~ta i') K Synchronization meeting within each transmitter station b
3'> 3- can be easily obtained, and the operation of synchronization becomes simple. ! Samurai vs. Satellite Yuraki etc.
When performing automatic correction, it is easy to control the workload.

Well, video (L4: originally has a synchronization signal like a signal 1-
There is no need for multiple synchronization signals.

Therefore, the entire device or multiple storage access system is greatly simplified and economical.

[Brief explanation of the drawing]

FIG. 1 shows one embodiment of the present invention 19! I O)' method 1 step 1
, 2121 (・Diagram showing the 11th calf form sent from the Engineering Standards Bureau, FIG.
Figure 1 shows the reference synchronization I= position. Figure 45 is a diagram showing the received waveforms at eight other stations at the time of initial acquisition.
The figure shows the principle of the phase matching circuit of the present invention, Figure 7 is an explanatory diagram of the phase matching operation, and Figure 8 shows the whole of the present invention +14
Figure 1 shows the composition. ■・Person I +fi star, 2...Reference transmitting station, :3・Other sending 1t■ station, 4, 5...Receiving station, 6...Line control station, 7
...Synchronization signal of limescale transmitting station, 8...Reference transmission (information from 1 station Ir3, 0.) 1 (Special transmission I, time allocated to 8 stations It, 10 Other transmission 1 language station.・Allotted time slot, 11...
Base synchronization number of other transmitting station, 12 Synchronization signal sent from other transmitting station), 3・ijJ change i1d 9j
j4 light generator, 14・combiner, 15 gate, 1() gate output, 17・feedback circuit, 18...single pulse σ9
Output level /L/, 19... Output level of Illll2 phase, 2()... Output level when +112 or matched,
21... Ambuna, 22... Kranha, 2:3... Multiplier, 21... Monitor, Song... Synchronization signal pulse generator, 2
6. Semi-fixed delay generator 3, ll"I': i'l output 11 wires per person Telegraph 1 "Conclusion 71! 1 Akira'1 Patent attorney for application Megumi Yamamoto --- Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] (till/U/Sponder is shared by multiple transmitting stations at a high rate of time.
Then, the O point of the transmitting station is connected to the reference station.10 synchronization signal and information 1.1. The same jt,
111 (the number of Q stations is set), the standard station is set to υ4 (M position),
3) Also, 1, □Jinkorepepe] to the local sending time i;'s reception position 1') ``1 I'' know, after that, the corresponding self 1; Send out the synchronization signal from your own station in such a way that it enters the Jlr. It is also possible to adjust the synchronous meeting 1
I;'1-division multi-rectangle access device. 1.4+ 4h71 In the jljj division multi-store access device 6- described in Claim 1, the local station's 1-sho 1 message received in return and the reference synchronization key signal for the local station,
Has an opening time that is at least longer than the time width of the periodic train.
It is characterized by adjusting the sending time of one signal from the local station so that the output is minimized by putting it into a gate circuit.
time division multiple access equipment. (3) In the time division multiple access device according to claim 1, the amplitude of the synchronization signal from the local station is adjusted, the transmission time is adjusted to a small period, and the synchronization ( ] is equal to the width of the engineering level synchronization signal and is characterized by 1 - loco and 1
- Time division multiple access equipment.