JPH02285822A - Time division multiple access system satellite communication system - Google Patents

Abstract

PURPOSE:To effectively utilize an ordering line burst by providing a sub reference burst output section and sending a sub reference burst having a prescribed unique word pattern to a location of the ordering line burst only when an ordering line data undetection signal is inputted. CONSTITUTION:An ordering OW line burst inputted to a burst demodulation section 1 in a sub reference station is separated into an OW line data and a preamble data and outputted to an expansion buffer section 2 and a unique word detection section 4. The OW line data inputted to the expansion buffer section 2 is read in an OW line data output section 3 at a low speed. A unique word detection section 4 detects a unique word in the inputted preamble data and outputs an Ow line data undetection signal when the data is not the OW line data and outputs an OW line data detection signal when the data is the OW line data. When the OW line data undetection signal is inputted to a sub reference burst output section 5, while the signal is inputted, the sub reference burst having a prescribed unique word pattern is sent to a position of the OW line burst.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a time division multiple access satellite communication system, and more particularly to a communication system for transmitting and receiving meeting line bursts.

[Prior Art] Time division multiple access (hereinafter referred to as TDMA) is a satellite communication method in which multiple earth stations use all or part of the frequency band of a satellite communication repeater (transponder) in a time-sharing manner. Each earth station needs to transmit data in the form of intermittent signals, that is, bursts, at a specific period, that is, the frame period of TDMA, but it is necessary to handle various digital signals in an integrated manner. It is known as an efficient communication method because it not only allows for communication but also enables the construction of highly flexible networks.

In this TDMA system, one of the plurality of participating earth stations is usually selected as the reference station, and two earth stations are selected as the reference station and sub-reference station, and this reference station provides the reference timing necessary for synchronization of the TDMA system. It transmits intermittent and periodic signals, i.e., reference bursts, to each station and performs other controls, and the sub-base station replaces the reference bursts when there are no more reference bursts transmitted from the reference station. It is common to transmit sub-reference bursts to maintain the current state of the network.

Conventionally, in a TDMA system consisting of a base station, sub-base station, and general station (participating earth stations excluding the base station and sub-base station in the TDMA system), the continuous incoming meeting line (hereinafter referred to as OW line) is The transmission data is input to the compression buffer section and converted to burst signal data, and then read into the multiplexing section at high speed, and preamble data containing a unique word indicating that it is OW line data is added. Sent as an OW line burst.

On the other hand, in the receiving system, as shown in FIG. 2, the OW line burst received by the burst demodulator 11 is separated into OW line data and preamble data.
The line data is input to the decompression buffer section 12 and output at low speed.
The data is read out to the W line data output 13. At the same time,
In the unique word detection unit 14, the received OW
A unique word in the preamble data of the line burst is detected to determine whether the received OW line burst data is OW line data.

When the data is OW line data, the unique word detection unit 14 sends an output to the OW line data output unit 13.
Since the W line data detection signal is input, oW line data is sent ahead.

oW When the line data detection signal is not input, that is, O
When W line data is not being received, or when other noise is being received, that data is not sent to the destination and is ignored.

[Problems to be solved] However, in the conventional TDMA satellite communication system described above, the OW line is only used for operation or maintenance meetings, and is usually hardly used after normal operation is achieved. Therefore, there is a problem that the OW line is not necessarily used effectively.

The present invention has been made in view of the above problems, and an object thereof is to provide a time division multiple access satellite communication system that can effectively utilize meeting line bursts.

[Means for Solving the Problems] In order to achieve the above object, the present invention comprises a reference station, a sub-standard station, and a general station, and the receiving system of the sub-standard station includes:
a burst demodulation section that receives a meeting line burst and separates it into meeting line data and pre-angle data; an expansion buffer section that inputs the meeting line data from this burst demodulation section and outputs it at low speed; and a preamplifier from the burst demodulation section. Inputs data and detects a unique word in it, determines whether the received meeting line burst data is meeting line data, and outputs a meeting line data detection signal if it is meeting line data. , a unique word detection unit that outputs a meeting line data undetected signal when the meeting line data is not detected, and a unique word detection unit that outputs a meeting line data undetected signal from this unique word detection unit, and receives the data input from the expansion buffer unit when the meeting line data detection signal is input from the unique word detection unit. a meeting line data output unit that outputs it as line data;
In a time division multiple access satellite communication system having a sub-standard station, a sub-standard having a unique word pattern is input to the transmission system of the sub-standard station while the meeting@line data undetected signal output from the unique word detection section is inputted to the transmission system of the sub-standard station. This configuration includes a sub-reference burst output section that outputs bursts.

[Operation] According to the above configuration, the meeting (OW) line burst is
The burst data is separated into line data and preamble data, and a unique word in the preamble data is used to determine whether or not the burst data is OW line data.

When the received OW line data is OW line data, the received OW line data is output from the OW line data output section based on the OW line data detection signal, while when it is not OW@H data, the received OW line data is output based on the OW line data non-detection signal. While the detection signal is being output, the sub-reference burst is output from the sub-reference burst output section.

[Example] Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram of the sub-base station in the TDMA satellite communication system according to the embodiment, and the burst demodulation section 1, decompression buffer section 2, and OW@ line data output section 3 are similar to those in the conventional system. It is the same as the corresponding circuit section in (Fig. 132). The unique word detection section 4 outputs an OW line data detection signal and an OW line data non-detection signal, and a sub-reference burst output section 5 is connected to the unique word detection section 4.

The sub-reference burst output section 5 outputs the OW line data undetected signal outputted from the unique word detection section 4.
While this signal is being output, a sub-reference burst with a unique pattern, such as a burst related to synchronization protection, is output.

According to the above configuration, the O input to the burst demodulator l
The W line burst is separated into 0W line data and preamble data, which are output to the decompression buffer section 2 and the unique word detection section 4. The OW line data input to the decompression buffer section 2 is read out to the OW line data output section 3 at low speed.

On the other hand, the unique word detection unit 4 detects a unique word in the input preamble data, determines whether or not the received OW line data is OW line data, and determines whether the data is OW line data or not. If it is not data, an OW line data non-detection signal is output, and if it is OW line data, an OW line data detection signal is output.

Then, when the OW line data non-detection signal is input from the unique word detection section 4 to the sub-reference burst output section 5,
While this undetected signal is input, a sub-reference burst having a predetermined unique word pattern is sent to the OW line burst position.

On the other hand, when the OW line data detection signal is input to the OW line data output unit 3, the data input from the decompression buffer unit 2 while this detection signal is being input is outputted as received OW line data, and the detection signal is If not entered, the data will not be sent further and will be ignored.

In this way, when the OW line burst is not used for transmitting and receiving OW line data, it can be used for purposes such as synchronization protection by inserting a sub-reference burst instead.

[Effects of the Invention] As explained above, according to the present invention, it is determined whether or not the received data is meeting line data based on the unique word of the meeting (OW) line burst received at the sub-base station, and this judgment is performed. Based on this, a meeting line data detection signal and a meeting line data non-detection signal are output. A sub-reference burst output section is provided, and a sub-reference burst with a predetermined unique word pattern is sent to the meeting line burst position only while the meeting line data undetected signal is being input. This has the effect of making it possible to effectively use meeting line bursts for protection purposes and improving the reliability of the satellite communication system.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a TDMA satellite communication system according to an embodiment, and FIG. 2 is a block diagram of a conventional TDMA satellite communication system. 1.11: Burst demodulation section 2.12: Decompression buffer section 3.13: OW line data output section 4.14: Unique word detection section 5: Sub-reference burst output section

Claims (1)

[Claims] Consisting of a standard station, a sub-standard station, and a general station, the receiving system of the sub-standard station includes a burst demodulator that receives the meeting line burst and separates it into meeting line data and pre-angle data, and a burst demodulator that receives the meeting line data from this burst demodulator. Preamble data is input from the decompression buffer section that inputs and outputs at low speed, and the burst demodulation section and unique words therein are detected to determine whether or not the received meeting line burst data is meeting line data. A unique word detection unit that outputs a meeting line data detection signal when the data is meeting line data, and a meeting line data non-detection signal when it is not meeting line data, and a unique word detection unit that detects the meeting line data from this unique word detection unit. In a time division multiple access satellite communication system having a meeting line data output section that outputs the data inputted from the expansion buffer section as reception meeting line data when a signal is input, A time division multiple access device characterized in that a sub-reference burst output section is provided that outputs a sub-reference burst having a unique word pattern while the meeting line data undetected signal output from the unique word detection section is input. satellite communication system.