JPH036941A - Network synchronizing signal repeater - Google Patents

Abstract

PURPOSE:To avoid the collision between a network synchronizing signal from a transmission station not through a relay station and a network synchronizing signal from a relay station by sending the network synchronizing signal at a point of time elapsed by an optional indefinite number of superframes after the network synchronizing signal is received. CONSTITUTION:A relay superframe optional selection circuit 10 selects automatically a relay superframe at random as soon as a reception network synchronizing signal 1 is inputted and outputs relay superframe information 11 representing what order number a selected relay superframe is located to a timing control circuit 12. When the information from a superframe counter 8 is coincident with the relay superframe information 11, the timing control circuit 12 outputs a superframe timing signal 13 to a network synchronizing signal generating circuit 14. Thus, even when the network synchronizing signal reaches the reception station and is received from the transmission station not via a relay station, collision and interference with the network synchronizing signal via the relay station do not take place.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention uses frequency hopping (Freqoe++cy HoppIIIg: F
Time division multiple access (Ti■e Div
ision Mul-tiple Access:T
This technology relates to a technology for avoiding so-called overreach interference, which occurs when a network synchronization signal is relayed in a DMA) type communication system, reaching the other station directly without passing through a relay station, and causing interference with the relayed signal. .

(Prior Art) Conventionally, the relay method in a TDMA communication system is a two-wave relay method, in which overreach interference is avoided by converting to a frequency different from the receiving frequency and relaying. In other words, when transmitting from station A to station B via a relay station,
The transmission frequency from the A station to the relay station is f, and the transmission frequency from the relay station to the B station is f2 (≠ft), that is, the B station receives at the frequency f2. Therefore, even if a signal with frequency 1 arrives directly from station A, it will not be received because the frequencies are different and interference will be avoided. However, in a TDMA (referred to as FH-TDMA) communication system that uses FH, the entire network Since hopping is always performed using the same frequency pattern, it is not possible to make the reception and transmission frequencies of the relay station different as in the two-wave relay system, and the reception frequency and the transmission frequency are the same at the point in time.

In the above example, the frequency of transmission from the relay station to station B is also fl. The transmitting and receiving frequencies of the relay station are f, , f2 . . . for each basic frame. Hopping with f......

(Problems to be Solved by the Invention) As described above, in the FH-TDMA communication system, the transmission frequency from station A on the transmitting side to the relay station, and the transmission frequency from the relay station to station B on the receiving side, that is, the reception at station B. Because the frequencies are the same, station A receives the network synchronization signal from the relay station and the network synchronization signal from station A, although there is a slight time difference due to the difference in propagation path length, resulting in a collision between the two. There is a problem that synchronization cannot be achieved.

In view of the above-mentioned problems, an object of the present invention is to transmit a received network synchronization signal with a delay of a random number of super frames so that the received network synchronization signal can be transmitted from a transmitting station without going through a relay station. An object of the present invention is to provide a network synchronization signal relay station that prevents collision between a network synchronization signal sent from a relay station and a network synchronization signal sent from a relay station.

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

That is, the network synchronization signal relay device of the present invention is a network synchronization signal relay device in a time division multiple access communication system that performs frequency hopping for each basic frame; a relay superframe arbitrary selection circuit for instructing the selection of a subsequent superframe; a superframe timing signal generation circuit for generating a superframe timing signal in response to a received network synchronization signal; A timing control circuit that detects a super frame timing signal corresponding to the selected super frame; and a network synchronization signal generation circuit that generates and transmits a network synchronization signal at the timing of the detected super frame timing signal. 1 is a network synchronization signal relay device characterized by comprising:

(Embodiments) Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a configuration block diagram of an embodiment of a network synchronization signal relay device of the present invention. Although the transmission format in the FH-TDMA communication system is not limited in the present invention, it is as shown in FIG. 2 for convenience of explanation. That is, T
One frame consists of a plurality of basic frames (10 in Fig. 2) to which one DMA channel is assigned,
A network synchronization signal is arranged at the beginning of a plurality of frames (four frames in FIG. 2) to constitute more than one frame.

In FIG. 1, the receiving network synchronization signal 1 has a time base 2
is reset, and the clock signal 3 is slave-synchronized. A basic frame (TDMA channel) counter 4 counts the clock signal 3 and outputs a basic frame timing signal 5. A frame counter 6 counts the basic frame timing signal 5 and outputs a frame timing signal 7. The super frame counter 8 receives the frame timing signal 7
A super frame timing signal generation circuit is composed of a zero or more time base 2, a basic frame counter 4, a frame counter 6, and a super frame counter 8, which count and output a super frame timing signal 9. On the other hand, the relay super frame arbitrary selection circuit 10 automatically selects a relay super frame at random (arbitrarily) at the same time as the reception network synchronization signal 1 is input, and relays the relay super frame to determine the number of the selected relay super frame. The super frame information 11 is sent to the timing control circuit 12
Output to. The timing control circuit 12 monitors the super frame timing signal 9 and relays super frame information 1.
1, super frame timing signal (for relay)
13 is output to the network synchronization signal generation circuit 14. The network synchronization signal generation circuit 14 generates a super frame timing signal (for relay) 1
3, a network synchronization signal 1' is generated.

In this way, the relay device transmits the network synchronization signal after an arbitrary number of super frames after receiving the network synchronization signal.

Therefore, even if the network synchronization signal from the transmitting station reaches the receiving station without passing through the relay station and is received, there will be no collision interference with the network synchronization signal that has passed through the relay station.

Next, the network synchronization signal relay device shown in FIG.
Figure 3 (a) shows the network synchronization signal relay operation when applied to an FH-TDMA communication system having two terminal relay stations.
) indicates the order of relaying, and Figure (b) indicates the timing of relaying. Terminal station A transmits a network synchronization signal to relay station B at timing ■. Diagonal lines indicate transmission of the network synchronization signal.)
, relay station B receives the signal at this timing ■, and transmits it to relay station C at timing ■ more than two frames later. Relay station C receives at timing ■ and transmits at timing ■ after the IH frame. The end station receives at timing ■. Therefore,
Even if terminal station A reaches relay station C without passing through relay station B, it will be received at timing ■ and will not collide with the receiving network synchronization signal at timing ■ mentioned above. Even if it arrives directly at the terminal station, it is received at timing ■ and does not collide with the network synchronization signal received at timing ■, and the transmission from relay station B reaches the end station without passing through relay station C. Even if it is received at timing ■, it does not conflict with the network synchronization signal received at timing ■.In this way, in addition to the regular network synchronization signal that goes through the relay station, there is also a signal that arrives and is received without going through the relay station. Even if the synchronization occurs, normal synchronization can be achieved as long as there is no collision between the two. In Figure 3, relay station B transmits after more than two frames have elapsed since receiving the network synchronization signal, and relay station C transmits after more than one frame has elapsed after receiving the network synchronization signal. The delay time is randomly determined by the relay superframe arbitrary selection circuit.

Therefore, relay station B receives and transmits at the timing shown in FIG. Except in cases where the transmission was delayed,
Collision of network synchronization signals at the end station will no longer occur.

(Effects of the Invention) As explained above, the network synchronization signal relay device of the present invention has the following features:
Since the network synchronization signal is sent after an arbitrary undefined number of super frames have passed after receiving the network synchronization signal, even if the entire network is hopping in the same frequency pattern in the FH□TDMA communication system, ,
The network synchronization signal received in the original relay order and the network synchronization signal received without passing through the relay station to be relayed are
Except in the case of a coincidence, there is no collision and there is an advantage that overreach interference can be avoided.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the network synchronization signal relay device of the present invention, FIG. 2 is a diagram showing an example of a transmission format in an FH-TDMA communication system, and FIG. 3 is a block diagram showing the configuration of an embodiment of the network synchronization signal relay device of the present invention. FIG. 2 is a timing diagram showing a relay operation of a network synchronization signal when applied to a two terminal station two relay station PH-TDMA communication system. l... Reception network synchronization signal, 1'... Network synchronization signal, 2... Time base, 3...
... Clock signal, 4 ... Basic frame counter, 5 ... Basic frame timing signal,
6...Frame counter, 7...
Frame timing signal, 8... Super frame counter, 9... Super frame timing signal, 10... Relay super frame arbitrary selection circuit, 1
1...Relay super frame information, 12...
...Timing control circuit, 13...Super frame timing signal (for relay), 14...Network synchronization signal generation circuit.

Claims (1)

[Claims] A network synchronization signal relay device in a time division multiple access communication system that performs frequency hopping for each basic frame; the relay superframe instructs selection of a superframe that is an arbitrary undefined number of superframes after a received network synchronization signal; a frame arbitrary selection circuit; a super frame timing signal generation circuit that generates a super frame timing signal in response to a received network synchronization signal; A network synchronization signal relay device comprising: a timing control circuit that detects a frame timing signal; and a network synchronization signal generation circuit that generates and transmits a network synchronization signal at the timing of the detected super-frame timing signal. .