JPH01288031A - Signal transmission system - Google Patents

Abstract

PURPOSE:To quicken the relief of a line fault due to line switching by several steps by including both the result of calculation of error correction (FEC) at a terminal station and the result of calculation of FEC at an intermediate relay station to a redundant bit of the FEC and sending the result. CONSTITUTION:An information bit is subject to speed conversion by an error correction coder 101 at the transmission end, a redundant bit B for error correction is added and another redundant bit C is added. When a signal is sent from the transmission end to the intermediate relay station, the signal is decoded by an error correction decoder 102 at the intermediate relay station. The signal in this case is coded again by an error correction decoder 101a at the intermediate relay station and the redundant bit B is sent to the next station as the redundant bit D. In this case, the redundant bit C is sent as it is to a subsequent station. Code error is detected by the redundant bit C to attain line switching thereby attaining code error rate detection time in a short time.

Description

[Detailed Description of the Invention] [Industrial Application Fields] The present invention relates to a signal transmission system that performs error correction in digital wireless communication, particularly a signal transmission system that performs error correction (FEC) encoding and decoding at intermediate relay stations. This paper relates to improvements in line monitoring methods.

[Prior Art] Transmission systems that perform error correction in digital wireless communication have been well known, and as this type of conventional technology, a system that performs error correction at an intermediate relay station has been adopted.

FIG. 2 shows an example of the configuration of a conventional signal transmission system that performs error correction and its FECEN CODER signal.

In the figure, 1.1a is a carrier terminal station, 101 is an error correction encoder (FECENCODER) at the sending end, and 102 is an error correction decoder (FECDECODER) at the intermediate relay station.
01 a is an error correction encoder in an intermediate relay station, 102
a is an error correction decoder at the receiving end.

In such conventional technology, the correction encoder 10 of the transmitting terminal station
The signal transmitted as error correction (FEC) redundant bits from 1 to 1 is decoded by the error correction decoder 102 of the intermediate relay station.

Then, the error correction (FECENCO) decoded here is
The signal D) is transmitted from the correction encoder 101a to the next station, and the receiving end station decodes only the error correction (FECENCOD) signal encoded at the previous station. there were.

Therefore, in this conventional technology, line quality monitoring at the receiving terminal station is performed by detecting the error rate using parity bits added to the information bits at the transmitting terminal station, and using this for line switching. Ta.

[Problems to be solved] However, in such conventional transmission systems, the signal transmitted to the receiving end station is subject to error correction (F) coded at the previous station.
ECENCOD) signal, and the error correction (FECENCOD) signal encoded by the previous station, that is, the transmitting terminal station.
The OD) signal is not sent to the receiving terminal station, but is decoded (FECDECOD) at the station next to the transmitting terminal station.

For this reason, error correction (FEC) signals are not used to monitor line quality at terminal stations, and line switching is performed simply by detecting the code error rate using parity pits and relieving line failures. There was only one.

Therefore, the code error rate detection using parity pits at the terminal station has the problem that line failures cannot be detected early.

The present invention has been made in view of such conventional problems, and an object thereof is to provide a signal transmission method that can detect faulty line failures at an early stage in digital wireless communication.

[Means for Solving Problems] In order to achieve the above object, the present invention provides a signal transmission system in which error correction is encoded and decoded at each station that performs digital wireless communication, and in which error correction calculations are performed at the terminal station. The system is configured to monitor line quality by transmitting both the result of error correction and the calculation result of error correction performed at the intermediate relay station to the next station as redundant bits for error correction.

[Example code] Next, preferred embodiments of the present invention will be described based on the drawings.

In order to solve the above-mentioned conventional problems, the present invention transmits both the FEC calculation result at the terminal station and the FEC calculation result at the intermediate relay station as redundant error correction (FEC) bits. It is characterized by being configured to do so.

FIG. 1 shows the configuration of a signal transmission system for error correction according to the present invention and its FECENCODER signal.

In the figure, 101 is an error correction encoder (FEC) at the sending end.
ENCODER), 102 is an error correction decoder (FECDECO-DER) in the intermediate relay station, 101a is an error correction encoder (FECENCODER) in the intermediate relay station, 1
02a is an error correction decoder (FECDECODER) at the receiving end.
).

Then, in the error correction encoder 101 at the sending end, the information bits are speed-converted and converted into redundant bits (B) for error correction (FEC).
is added, but at this time, another redundant bit (C) is added.

Then, when a signal is sent from the sending end to the intermediate relay station, this signal is transmitted to the error correction decoder 10 at the intermediate relay station.
2 to be decrypted. Error correction (FE) used at this time
The redundant bit of C) is only (B), and the redundant bit of (C)
is not used.

Then, the signal at this time is encoded again by the error correction decoder 101a at the intermediate relay station, and the redundant bit (B) becomes a redundant bit (D) and is transmitted to the next station. At this time, the redundant bit (C) is transmitted as is to the lower station.

In other words, the FEC operation result (redundant bit (C)) at the sending end
will be transmitted as is to the lower stations in sequence.

The present invention uses this redundant bit (C) to monitor line quality, detect code errors using the redundant bit (C), and switch lines.

Note that the present invention is not limited to the above embodiments,
Various modifications can be made within the scope of the invention.

[Effects of the Invention] As explained above, according to the present invention, the error correction (FE)
By transmitting both the FEC calculation result at the terminal station and the FEC calculation result at the intermediate relay station in the redundant bits of C), error correction ( FEC) can be used to detect the code error rate in a short period of time, which has the effect of making it possible to improve line failure by several steps by switching the line.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the configuration of a preferred embodiment of the signal transmission system according to the present invention and the FECENCODER signal. FIG. 2 is an explanatory diagram of the configuration of the conventional signal transmission system and the FECENCODER signal.
FIG. 2 is an explanatory diagram of an ODER signal. 101: Error correction encoder 102: Error correction decoder Representative Patent attorney Kihei Watanabe

Claims (1)

[Claims] (1) In a signal transmission system in which each station performing digital wireless communication performs error correction encoding and decoding, the results of error correction calculations performed at the terminal station and the calculation results of error correction performed at intermediate relay stations. A signal transmission method characterized in that line quality is monitored by transmitting both of the information and the information to the next station as redundant bits for error correction.