RS decoder and decoding method for EPON system

Abstract

Disclosed are an RS encoder and an encoding method for an EPON system. Data are transmitted by a frame synchronization device to a data buffer BUF-1, a syndrome calculating circuit, an FEC block information storage device, a syndrome temporary storage device and a syndrome calculating result storage device; the data buffer BUF-1 provides data for a data buffer BUF-2, the FEC block information storage device and the syndrome calculating result storage device; the data buffer BUF-2 finishes error correcting output with a Chien search / Forney algorithm module; the syndrome calculating result storage device provides data for the Chien search / Forney algorithm module via a BM iterative circuit and a code correction device. The method transforms a common RS (255, 339, and 8) encoder by combining characteristics of an EPON system FEC frame structure and special requirements of the EPON system, thereby enabling the FEC sub-layer function of the EPON system to be realized smoothly.

Description

technical field [0001] The invention relates to the field of optical fiber communication, in particular to an RS decoder and a decoding method used in an EPON system. Background technique [0002] The Ethernet passive optical network EPON system is a network form that utilizes the PON point-to-multipoint P2MP topology of the passive optical network and adopts the single-fiber bidirectional transmission mode of passive optical fiber to carry multiple services on the Ethernet. At present, IP / Ethernet applications account for more than 90% of the entire LAN communication. Because of the above-mentioned economical and efficient structure, the EPON system has become an effective communication method for connecting the end users of the access network. [0003] The Ethernet passive optical network EPON system consists of an optical line terminal OLT located at the central office, a number of optical network units ONU located at the remote end, and a passive optical distribution net...

AI Technical Summary

Problems solved by technology

[0015] 4. FEC packets and non-FEC packets have the same delay

[0017] The above five characteristics of the EPON system determine that the RS decoding scheme of the EPON system is very different from the ordinary RS decoder in terms of synchronous design concepts, so the ordinary RS decoder is not suitable for the special requirements of the EPON system. FEC sublayer frame structure; and the asynchronous nature of Ethernet and variable frame length determine that the synchronization method of ordinary RS decoder is not suitable for EPON system

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