Parity check code decoder and receiving system

Abstract

The invention relates to a parity check code decoder, which is suitable for receiving a channel quality ratio and at least N bits to be decoded. The parity check code decoder comprises a verification device, a reliability generating device, a bit exchanging device, an exchange checking device and a reliability updating device, wherein the verification device takes each bit to be decoded as a one-bit node and makes one matrix multiply an N-bit node to obtain an (N-K) checking node; the reliability generating device generates a reliable pointer, which is used as an abnormal check index transmitted to the checking node by the bit node, for each bit node; the bit exchanging device generates an abnormal bit pointer for each checking node so as to transmit to the bit node; the exchange checkingdevice updates a plurality of abnormal check pointers, which are used to be transmitted to the checking nodes by the bit nodes, based on the abnormal bit pointers; and the reliability updating deviceupdates the reliable pointer of each bit node according to the abnormal check pointer so as to determine an updating value of each bit node.

Description

technical field [0001] The present invention relates to a decoding technology, in particular to a low-density parity-check code (low-density parity-check code, LDPC) decoder and a receiving system. Background technique [0002] Low Density Parity Check Code (LDPC) is a type of error correction code. Since the coding gain is close to the Shannon limit, it has been gradually adopted in some communication standards recently, such as: the second generation of satellite digital video broadcasting (Digital Video Broadcast-Satellite version 2, DVB-S2), digital TV terrestrial multimedia broadcasting (Digital Terrestrial Multimedia Broadcasting, DTMB) or IEEE 802.11. At the receiving end, the LDPC decoder regards each bit to be decoded from the channel as a bit node, and the N bit nodes must satisfy (N-K) conditions to obtain correct decoding. These conditions are called check nodes. [0003] In order to reduce channel interference, the LDPC decoder uses the check nodes to check w...

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Problems solved by technology

However, the offset does not change with the channel quality, resulting in the probability of the same node obtained by iteration is still not accurate enough, and the reliability of the decoded output is not good.

[0005] In the paper (LDPC Decoding Algorithm with Estimation of Noise Variance) proposed by Changzheng Ma and Boon Poh Ng in 2006, although it is also recommended to use the updated channel quality for the next iterative calculation, the calculation process is quite complicated, so will cause a burden on the hardware

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