JPS584853B2 - Signal transmission method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a transmission system that makes effective use of a transmission band occupied by intermittently transmitted signals.

It is a signal transmission method that is especially suitable for communication methods that require high efficiency in the use of transmission bands, such as satellite communication methods.
The present invention relates to a transmission method in which signals that are transmitted intermittently are transmitted simultaneously.

Traditionally, when an indirect signal is transmitted simultaneously with another continuous signal, the continuous signal is transmitted continuously in the band it occupies, the intermittent signal uses the required band for the required time, and the band is transmitted intermittently. There was a drawback that during times when there was no target signal, there was no transmission, resulting in low utilization efficiency of the transmission band.

In order to improve this, in the case of intermittent signal transmission with a small duty, a method is known in which the signal is stretched in time and the transmission band is compressed, but this method complicates the equipment and is not necessarily economical.

The present invention improves this and aims to provide an economical transmission system with high band utilization efficiency when transmitting other continuous signals at the same time as intermittent signals.

According to the present invention, intermittent signals are transmitted by preferentially occupying a band each time the signal occurs, and continuous signals that are being transmitted at the same time are interrupted for the time period during which the intermittent signals are being transmitted. It is characterized in that the intermittent signal is delayed within the transmitter and is transmitted as a parallel signal at the same time as the continuous signal at that time after the intermittent signal is interrupted.

This will be explained in detail below using the drawings.

FIG. 1 is a time chart according to a conventional method showing frequency bands occupied by transmission signals.

Signal A is an intermittent signal, for example, an image signal that is transmitted intermittently.

Signal B is a continuous signal, for example a continuously transmitted data signal.

FIG. 2 is a block diagram of a conventional device for transmitting this signal.

S(A) is the signal source of signal A, S(B) is the signal source of signal B, and these two signals are given to the transmitter TX, and the transmission path TR
is transmitted and received by the receiver RX.

The transmission path TR may be wireless or wired.

The demodulated signal of the receiver RX is that signal A is R(A) and signal B is R
(B) are obtained respectively.

In such a conventional system, as can be seen from FIG. 1, the band in which the intermittent signal A is transmitted is vacant during the time when there is no signal, and the frequency band is used inefficiently.

Particularly when a satellite relay is used for the transmission path, if the band is wide, interference with other communications becomes a problem, and the design of the repeater becomes complicated.

FIG. 3 is a time chart showing frequency bands occupied by transmission signals according to the embodiment of the present invention.

Compared to the conventional example shown in FIG. 1, the intermittent signal A is placed as is, and the continuous signal B is separated into B1 and B2 and placed in the idle time of signal A.

In other words, the part B1 shown by the broken line of the continuous signal B is
A delay is applied within the transmitting device, and the B2 portion is directly placed at the frequency positions of B1 and B2 shown by the solid line without being applied with delay, and is transmitted as a parallel signal.

When the receiving device demodulates this signal, if only the signal B2 is delayed so that it falls between the signal B1, the received output will be a delayed signal that is equivalent to the signal B shown by the broken line in Figure 3. can get.

At this time, the delay time given to signal B1 by the transmitting device and the delay time given to signal B2 by the receiving device are equal.

With such a signal configuration, the frequency band of this transmission signal can be narrowed from W1 to W2 shown in FIG. 3, and the frequency band utilization efficiency can be improved.

FIG. 4 is a diagram showing the configuration of an apparatus according to an embodiment of the present invention for realizing this.

In the figure, S(A) and S(B) are signal sources of signals A and B, respectively, DIS is a distribution circuit, DL1 is a delay circuit, and TX is a transmitter.

Signal A is applied directly to the transmitter TX, and the timing signal of signal A is configured to control the distribution circuit DIS.

Signal B is decomposed into B1 and B2 by the distribution circuit DIS,
A delay circuit DL1 applies a delay to B1, and each signal is applied to the transmitter TX.

The output of the transmitter is input to the receiver RX via the transmission path TR, and the signal A is demodulated as it is, and the signal B is demodulated as it is, and the B2 part is sent to the delay circuit DL2.
It is obtained by selecting the signals that have passed through the composing circuit COM.

Next, an example of application of the present invention will be explained with reference to FIG.

FIG. 5 is a diagram showing an example of the configuration of a satellite communication system.

There are ground facilities at points K, L, and M on the ground, and the satellite ST
A communication repeater RP and an image transmitter P are mounted on the tower.

This satellite ST is a satellite that can not only relay data signals but also transmit images of the ground taken by the satellite.

DIX is a diplexer that separates antenna transmission and reception signals according to direction.

Signal B is a source continuous signal, and is transmitted from point K to point M via repeater RP of satellite ST.

On the other hand, the signal A is an intermittent image signal of the earth generated from the image transmitter P on the satellite.

If the present invention is applied to such a system, the intermittent signal A
When transmitting, the transmission path is opened and this is transmitted preferentially, and the signal B generated during this time may be delayed at point K and transmitted later as a parallel signal.

At this time, as a control signal for intermittent signal B, K
Use signal A that can be received at the point.

Furthermore, in this application example, if the K point and the L point are placed at the same point, the system becomes even more economical.

Furthermore, the method of the present invention can be applied to a radar device that transmits intermittent signals, and the frequency used can be used for other communications.

In the above description, it has been described that a continuous signal is divided into two to form parallel signals, but this invention is not limited to two, but the present invention can be similarly implemented with a plurality of signals.

Furthermore, the present invention can be implemented with regard to intermittent signals, whether they occur periodically or irregularly.

[Brief explanation of drawings]

FIG. 1 is a transmission signal time chart of a conventional example. FIG. 2 is a diagram showing the configuration of a conventional device. FIG. 3 is a transmission signal time chart of an embodiment of the present invention. FIG. 4 is a diagram showing the configuration of an apparatus according to an embodiment of the present invention. FIG. 5 is a system configuration diagram showing an application example of the present invention. S(A), S(B)...Signal source, TR...
...Transmission path, R(A), R(B)...Reception output signal, TX...Transmitter, RX...Receiver, DIS...・Distribution circuit, COM...
Synthesis circuit, DL1, DL2...Delay circuit, ST
・・・・・・Satellite, P・・・・・・Image transmitter, RP・
...Repeater, DIX...Diplexer.

Claims (1)

[Claims] 1 In the method of transmitting intermittent signals and continuous signals,
Intermittent signals are transmitted by preferentially occupying a band each time the signal occurs, and continuous signals are delayed within the transmitter by interrupting transmission during the time when the intermittent signal is being transmitted. A signal transmission method characterized in that after an intermittent signal is interrupted, it is transmitted as a parallel signal at the same time as the continuous signal at that point.