JP2757617B2 - Time division multi-way multiplex communication system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a time division multi-way multiplex communication system, and more particularly, to data relay and loopback control between a single master station, a plurality of relay stations, and slave stations.

[0002]

2. Description of the Related Art Conventional time-division multi-way multiplex communication systems include the following.
It comprises one master station, a plurality of relay stations and slave stations, transmits downlink signals between the stations by frame synchronization, and transmits uplink signals as burst signals with delay adjustment. When each relay station loops back an uplink signal to a downlink signal for the reason of frame asynchronous detection or the like, since the time positions of the uplink frame and the downlink frame are different, the uplink signal is delayed by the time difference between the uplink frame and the downlink frame. And loop back.

[0003]

In the above-described conventional time division multi-directional multiplex communication system, when looping back at a relay station, in order to loop back an uplink signal, a time difference between an uplink frame and a downlink frame is calculated. However, there is a disadvantage that hardware for the delay is required because the signal must be delayed and multiplexed with the downstream signal.

[0004]

SUMMARY OF THE INVENTION A time division multi-directional multiplex communication system according to the present invention is a hierarchical bus type time division multi-directional multiplex communication system comprising one master station, at least one relay station and a slave station. A multiplex transmission means for multiplexing the frame synchronization pattern and the relay number of the own station on the downlink signal based on the frame pulse of the own station and transmitting the multiplexed signal to the lower station, and looping the uplink signal from the lower station to the downlink signal. Frame synchronization means for providing the master station and the relay station with a loopback means capable of monitoring the frame synchronization pattern of a downlink signal from an upper station and generating the frame pulse in the relay station and the slave station. And delays the upstream signal of the own station with respect to the downstream signal of the own station by a predetermined delay amount corresponding to the relay number of the own station. A delay transmitting means for multiplexing with a signal, performing a predetermined delay adjustment corresponding to the distance to the upper station, and transmitting the same as an uplink burst signal to the upper station; And a relay number calculating means for calculating the relay number of the own station by a predetermined calculation and using the relay number of the master station as the relay number of the own station in a loopback state. .

In the above configuration, the frame synchronization means generates the frame pulse synchronized with the frame synchronization pattern when the downlink signal from the upper station is in a frame synchronization state, and generates the frame pulse when the downlink signal is in a frame asynchronous state. Running, generating the frame pulse, the loop-back means of the relay station, when receiving the information indicating the frame asynchronous state from the frame synchronization means, to loop back the upstream signal from the lower station to the downstream signal, A structure for sending information indicating a loopback state to the relay number calculating means,
Further, the relay number of the master station may be "0", and the relay numbers of the relay station and the slave station may be the number of relay stages counted from the master station.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings.

FIG. 2 is a diagram showing an outline of a system configuration according to an embodiment of the present invention. FIG. 6A shows that, among the configurations in which the master station, the relay station, and the slave station wirelessly perform time-division multi-directional multiplex communication in a hierarchical bus configuration, the master station B0 transmits the relay station Rm (m = 1 to n−
1) is extracted from the configuration in which “n + 1” stations are connected in series up to the slave station Tn. The upper station (master station B0 or relay station Rm) and the lower station (relay station Rm + 1 or slave station Tm) are extracted.
n). Here, the numbers of the stations B, R, and T are the number of relay stages counted from the master station when the master station B is 0.

Further, as shown in FIG. 2B, a down frame 100 of a down signal includes a frame synchronization pattern (F) 1.
01 and a relay number transmission channel (RCH) 102 are provided and continuously transmitted to lower stations. The upstream signal is
As shown in FIG. 2C, an upstream frame 200 is transmitted by a burst signal to an upper station.

FIG. 3 is a block diagram of the master station B0 of FIG.
Is a block diagram of the relay station Rm (m = 1 to n-1) in FIG. 2,
FIG. 5 is a block diagram of the slave station Tn of FIG. 3 to 5
The multiplexing circuit 11 is a circuit that multiplexes a frame synchronization pattern and a relay number on a downlink baseband signal based on a frame pulse. The modulation / demodulation circuit 12 is a modulation / demodulation circuit that modulates a baseband signal into a radio frequency and vice versa. The frame synchronization circuit 25 monitors the frame synchronization pattern in the downlink baseband signal sequence to determine frame synchronization / asynchronization, and when in the frame synchronization state, the frame synchronized with the frame synchronization pattern (F) 101 from the upper station. It is a circuit that generates a pulse and generates a frame pulse by self-running when the frame is in an asynchronous state. The relay number calculating circuit 26 of the relay station separates the relay number multiplexed in the upper station from the relay number transmission channel (RCH) 102 based on the frame pulse and calculates the relay number of the own station when the loop back is not performed. In the loop-back state, the relay number of the master station is used as the relay number of the own station. The relay number operation circuit 36 of the slave station, like the relay number operation circuit 26 of the relay station in the non-loopback state, uses the relay number transmission channel (RCH) 1 based on the frame pulse.
From 02, the relay number multiplexed in the upper station is separated and the relay number of the own station is calculated. The fixed delay circuit 27 is a circuit that applies a fixed delay determined by the relay number of the own station to the uplink signal of the own station. The delay adjusting circuit 28 of the relay station multiplexes the signal delayed by the fixed delay circuit 27 with the upstream signal demodulated by the modem 12 from the lower station,
The slave station delay adjustment circuit 38 is a circuit that adjusts the amount of delay according to the distance to the higher-level station and outputs a signal delayed by the fixed delay circuit 27 as a burst signal. Control is performed so that the upstream burst signals demodulated by the circuit 12 are arranged in a line on the time axis. The loopback circuit 13 includes the loopback control circuit 1
This is a circuit which receives the control of 4 or 24, multiplexes the upstream signal received by the modulation / demodulation circuit 12 facing the lower station into the downstream signal input to the multiplexing circuit 11 as it is, and loops back. The loopback control circuits 14 and 24 accept start-up information by manual operation in addition to loopback start-up information from other circuits.

FIG. 1 shows the time on the horizontal axis and the distance between the stations on the vertical axis, and shows how the downstream and upstream signals transmitted from each station are delayed according to the distance and transmitted to each station. FIG. 3A shows the signal delay when the loop-back is not performed, and FIG. 4B shows the signal delay when the loop-back is performed. As can be seen from FIG. 1, the fixed delay amount distribution among the stations is distributed at t = T / n, where n is equally divided among (n + 1) stations, where T is the frame period. 1
In the case of (A), (n-
1) t, (n−2) t,..., (Nm−1) t,.
0 is added. Also, the vertical axis represents the equivalent distance l = L obtained by dividing the distance L where the time when the signal goes from the master station B0 to the slave station Tn and returns by just the delay caused by the distance is exactly equal to n by n.
/ N is assigned equally to each station, but the time difference corresponding to the difference between the actual distance and the equivalent distance l
And 38 have already been adjusted.

In the above configuration, the operation when the loop-back is not performed at all stations and the operation when the loop-back is performed at the relay station Rm will be described.

(1) Operation When Loopback is Not Performed in All Stations In the master station B 0, a frame synchronization pattern based on a frame pulse and a relay number “0” are multiplexed by a multiplexing circuit 11 on a downlink baseband signal, and modulation / demodulation is performed. Circuit 12 to lower station R
1 is transmitted.

In the lower station R1, the downstream baseband signal output from the modulation / demodulation circuit 12 facing the master station B0 is calculated as follows.
The frame synchronization circuit 25 detects the frame synchronization pattern and outputs a frame pulse synchronized with the frame synchronization pattern. Next, the relay number calculation circuit 26 separates the relay number “0” multiplexed in the master station B0 from the RCH 102 in the downstream frame 100 based on the frame pulse, and adds
The number "1" is output as the relay number of the R1 station. In the fixed delay circuit 27, after adding the fixed delay amount (n-1) t determined by the relay number "1" to the upstream signal, the signal delayed by the fixed delay circuit 27 by the delay adjustment circuit 28 and the modem 12 Is multiplexed with the downstream signal demodulated by the lower station R2, the delay amount is adjusted according to the distance from the upper station (master station) B0, and the modulated signal is converted into a burst signal.
From the upper station B0, and the modulation / demodulation circuit 12 of the upper station B0.
Are controlled in such a manner that the uplink burst signals demodulated by the above are arranged in a line on the time axis, and the temporal positions of the downlink and uplink frames are equalized.

In the R1 station, the multiplexing circuit 11 uses the frame pulse from the frame synchronization circuit 25 as a reference to
The relay number “1” of one station is multiplexed on the RCH 102, the frame synchronization pattern 101 is multiplexed, and transmitted from the modem circuit 12 to the lower station.

FIG. 1A shows the flow of a signal by the above operation.
This will be described below. The downlink signal transmitted from the master station B0 is
Starting at point a0, the signal is received at relay station R1 at point a1.
Next, the upstream burst signal transmitted from the relay station R1 starts from the point a1, is delayed by (n-1) t with respect to the downstream signal by the fixed delay circuit 27, and then reaches the point b1. At 28, the delay is adjusted so that the master station B0 receives the signal at the point b0, and arrives at the master station B0. Therefore, in the master station B0, the uplink burst signal is received at the same time position in the uplink frame 200 as in the downlink frame 100.

Therefore, in the above state, if the loopback circuit 13 is turned on by the loopback control circuit 19 of the master station B0, the upstream signal can be looped back to the downstream signal without delay.

Similarly, the relay number "m" multiplexed on the downstream signal by the upper station Rm is separated and calculated by the lower station Rm + 1 to become the relay number (m + 1), and becomes the relay number (m + 1).
+1) fixed delay amount (n- (m + 1))
Since t is added to the upstream signal of the lower station Rm + 1 to adjust the delay amount, the downstream signal of the station Rm + 1 goes from the point a0 to the point am + 1 in FIG. m-1) t to reach the point bm + 1,
It can be seen that it is attached to b0.

(2) Operation when Loopback is Performed at Relay Station Rm An operation when loopback is performed at the relay station Rm because frame synchronization cannot be achieved between the relay stations Rm-1 and Rm will be described.

In the relay station Rm, the frame synchronization circuit 25
However, since the frame synchronization pattern cannot be detected from the downlink baseband signal output from the modulation / demodulation circuit 12 facing the upper station Rm-1, the frame is determined to be in the frame asynchronous state.
Therefore, the frame synchronization circuit 25 runs on its own and outputs a frame pulse by itself, and the loopback control circuit 24
To output a signal indicating an asynchronous state. The loop-back control circuit 24 turns on the loop-back circuit 13 to loop back the upstream signal to the downstream signal, and notifies the relay number operation circuit 26 of the loop-back state. When receiving the information indicating that the loop back state is set, the relay number operation circuit 26 sets the relay number of the master station to the relay number “0” and outputs it. The relay number “0” is multiplexed by the multiplexing circuit 11 together with the frame synchronization pattern (101) and transmitted to the lower station Rm + 1. Accordingly, the relay number received by the lower station Rm + 1 becomes "0", and the relay number calculation circuit 26 of the lower station Rm + 1 outputs "1" as the relay number. This gives a fixed delay amount of (n-1) t.

The signal flow due to the above operation is shown in FIG.
(B). First, the downlink signal transmitted from the upper station Rm starts from the point cm, and the point c at the lower station Rm + 1.
m + 1. Next, the upstream burst signal transmitted from the lower station Rm + 1 starts at the point cm + 1, reaches the point dm + 1 after being delayed by (n-1) t with respect to the downstream signal by the fixed delay circuit 27, and reaches the delay adjustment circuit 28. At upper station R
m, the delay is adjusted so as to be received exactly at the point dm and reaches the upper station Rm.
At the same time position as the downlink frame 100, the uplink burst signal is received. Therefore, in the relay station Rm, the uplink signal can be looped back to the downlink signal without delay.

In this embodiment, the description has been given of the configuration in which the slave stations Tn are arranged in series with the (n + 1) stations from the master station B0 through the relay station Rm. The applicability is clear from the above description.

[0022]

As described above, according to the present invention, means for multiplexing the relay number of its own station in the master station / relay station and sending it to the lower station, and looping up the upstream signal from the lower station to the downstream signal. Means for the relay station, according to the non-loopback state / loopback state, either the relay number calculated based on the relay number of the upper station or the relay number of the master station as the relay number of the own station. In the loopback state, in a loopback state, it is possible to control so that the time positions of the uplink and downlink frames for the lower station coincide with each other, and the uplink signal can be looped back to the downlink signal without delay. effective.

[Brief description of the drawings]

FIG. 1 is a diagram showing transmission states of uplink and downlink signals between stations according to an embodiment of the present invention. FIG. 1 (A) shows a signal at the time of non-loopback, and FIG. 1 (B) shows a signal at the time of loopback. Indicates a delay state.

FIG. 2 is a diagram showing an outline of a system configuration according to an embodiment of the present invention; FIG. 2A is a diagram showing a station configuration; FIG. 2B is a diagram showing a configuration of a downlink signal; (C) is a diagram showing a configuration of an uplink signal.

FIG. 3 is a block diagram illustrating a configuration of a master station in FIG. 2;

FIG. 4 is a block diagram illustrating a configuration of a relay station in FIG. 2;

FIG. 5 is a block diagram illustrating a configuration of a slave station in FIG. 2;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Multiplex circuit 12 Modulation / demodulation circuit 13 Loopback circuit 14, 24 Loopback control circuit 25 Frame synchronization circuit 26, 36 Relay number calculation circuit 27 Fixed delay circuit 28, 38 Delay adjustment circuit 100 Downstream frame 101 Frame synchronization pattern (F) 102 Relay Number transmission channel (RCH) 200 Up frame

Claims (4)

(57) [Claims] In a hierarchical bus type time-division multi-directional multiplex communication system comprising one master station, at least one relay station and each slave station, a downlink signal has a frame synchronization pattern based on its own frame pulse. Multiplexing means for multiplexing the relay number of its own station and sending it to the lower station, and loopback means capable of looping up signals from the lower station to down signals are provided in the master station and the relay station, Further, to the relay station and the slave station, a frame synchronization means for monitoring the frame synchronization pattern of a downlink signal from an upper station and generating the frame pulse, and an uplink signal of the own station corresponding to the relay number of the own station. A predetermined delay amount with respect to the downlink signal of the own station, and when there is an uplink signal from a lower station, multiplexes the uplink signal with the uplink signal to obtain a predetermined delay adjustment corresponding to the distance to the upper station. Delay sending means for adjusting and sending to the upper station as an uplink burst signal, and, when in a non-loopback state, extracting the relay number of the upper station from the downlink signal from the upper station and performing a predetermined calculation to determine the relay number of the own station. And a relay number calculating means for setting the relay number of the master station as the relay number of the own station in a loopback state. 2. The frame synchronization means generates the frame pulse synchronized with the frame synchronization pattern when a downlink signal from the upper station is in a frame synchronization state,
2. The time-division multi-way multiplex communication system according to claim 1, wherein the frame pulse is generated by self-running in a frame asynchronous state. 3. The loopback means of the relay station, upon receiving the information indicating the frame asynchronous state from the frame synchronization means, loops an uplink signal from a lower station back to a downlink signal, and loops back to the relay number calculation means. 3. The information indicating a back state is transmitted.
The time-division multi-way multiplex communication method described. 4. The relay number of the master station is set to “0”, and the relay numbers of the relay station and the slave station are set to the number of relay stages counted from the master station. The time-division multi-way multiplex communication method described.