Low density parity check code and decoding system in cascade connection with 4QAM-NR

A low-density parity and check code technology, applied in multi-carrier systems, baseband system components, error detection by signal space coding, etc., can solve the problem of not considering hard decision information and multi-path channels.

Inactive Publication Date: 2010-12-22
SUNPLUS TECH CO LTD
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

However, this patent does not consider the use of hard decision information related to QAM symbols, and only considers the Additive White Gaussian Noise (AWGN, Additive White GaussianNoise) channel, but does not consider the more practical multipath channel
[0010] It can be seen from the above that in the existing DTMB system, there is still room for improvement in the decoding method of cascading low-density parity-check code (LDPC Code) and 4QAM-NR code.

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  • Low density parity check code and decoding system in cascade connection with 4QAM-NR
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  • Low density parity check code and decoding system in cascade connection with 4QAM-NR

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[0047] In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and examples.

[0048] Figure 4 It is a structural schematic diagram of a decoding system in which a low-density parity-check code and a 4QAM-NR code are concatenated in the present invention. See Figure 4 , is the receiving end of the present invention for the DTMB digital television system, and is applicable to a decoding system in which low-density parity-check code (LDPC Code) and 4QAM-NR code are concatenated in single-carrier or multi-carrier mode. The system 400 includes a channel estimation and equalization device (channel estimator / equalizer) 410, a data partition device (data partition device) 420, an NR decoding device 430, a time de-interleaving device (de-interleaver) 440, and a noise power estimation device (noise power estimator) 450 , logarithmic si...

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Abstract

The invention discloses a decoding system of a low density parity code and a cascaded 4 QAM-NR (Nordstrom-Robinsion) code, which is applicable to a DTMB (Digital Terrestrial Multimedia Broadcast) and comprises two decoding phases. Firstly, the 4 QAM-NR is decoded by an NR decoding device, a hard decision message of a decoded sign and a message of a channel state are sent to a log similarity valueratio device for operating out a log similarity value ratio which does not have the hard decision, an adder is utilized to add a correction term which is relevant to the hard decision message so as to operate out the log similarity value ratio, and then the log similarity value ratio is sent to a decoding device of the low density parity code for decoding.

Description

technical field [0001] The present invention relates to the field of wireless transmission technology, in particular to a low-density parity-check code (LDPC, Low-density Parity-check Codes) and quadrature amplitude modulation-NR (4QAM-NR, Quadrature Amplitude Modulation-Nordstrom-Robinson) code Cascaded decoding system. Background technique [0002] Low-density parity-check codes have been widely used in wireless communication systems due to their high coding gain in performance, easy approach to Shannon Bound, and simple and regular architecture for easy implementation. middle. [0003] However, in the decoding process of the low-density parity-check code, before the word to be decoded (Codeword) is transmitted to the decoder, it is necessary to calculate the logarithmic similarity ratio (LLR, Log Likelihood Ratio) of each coded bit. For example, consider a cascaded coding architecture where, when a low-density parity-check (LDPC) code is used as the outer code, taking i...

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H03M13/29H03M13/25H04L25/06H04L27/38
Inventor 曾俊杰谢志农
Owner SUNPLUS TECH CO LTD
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