Synchronized method of low-density parity-check (LDPC) data blocks in 32quadrature amplitude modulation (32QAM) and 4quadrature amplitude modulation-nordstrom robinson (4QAM-NR) of digital television terrestrial broadcasting system (DTMB)

A data block and data technology, applied in transmission systems, synchronization devices, multi-carrier systems, etc., can solve problems such as long synchronization time, and achieve the effects of avoiding errors, low design complexity, and less hardware and software resources.

Active Publication Date: 2011-09-28
MAXSCEND MICROELECTRONICS CO LTD
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The advantage is that the structure is simple, and the error of the LDPC synchronization posi

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  • Synchronized method of low-density parity-check (LDPC) data blocks in 32quadrature amplitude modulation (32QAM) and 4quadrature amplitude modulation-nordstrom robinson (4QAM-NR) of digital television terrestrial broadcasting system (DTMB)
  • Synchronized method of low-density parity-check (LDPC) data blocks in 32quadrature amplitude modulation (32QAM) and 4quadrature amplitude modulation-nordstrom robinson (4QAM-NR) of digital television terrestrial broadcasting system (DTMB)
  • Synchronized method of low-density parity-check (LDPC) data blocks in 32quadrature amplitude modulation (32QAM) and 4quadrature amplitude modulation-nordstrom robinson (4QAM-NR) of digital television terrestrial broadcasting system (DTMB)

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[0025] combine figure 1 Shown, the synchronous method of the LDPC data block of 32QAM and 4QAM-NR in the DTMB system of the present invention in one embodiment, specifically comprises the steps:

[0026] Step 1: Initialize the synchronization position of the LDPC data block, and set the start position of the LDPC data block of the first data frame at the frame header of the data frame.

[0027] There are two types of LDPC data block synchronization positions. combine figure 2 As shown, in the 32QAM modulation mode, the first synchronous position is the starting position of the LDPC data block, at the frame header (the starting position) of the data frame; the second synchronous position is in the middle of the LDPC data block, that is, the starting position of the LDPC data block The frame header of the current data frame has a distance of half an LDPC data block. In the 4QAM-NR modulation mode, the first synchronization position is the start position of the LDPC data bloc...

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Abstract

The invention discloses a synchronized method of low-density parity-check (LDPC) data blocks in 32quadrature amplitude modulation (32QAM) and 4quadrature amplitude modulation-nordstrom robinson (4QAM-NR) of digital television terrestrial broadcasting system (DTMB). The method comprises the following steps: initializing synchronization positions of LDPC data blocks and setting beginning positions of the LDPC data blocks of a first data frame in a frame header of the data frame; receiving new frame data; detecting whether the received frame data is all-zero codes; continuously receiving next frame data if the frame data is all-zero codes; conducting a subsequent determine if the frame data is not all-zero codes; splitting the data frame to a plurality of LDPC data blocks according to the synchronization positions of LDPC data blocks; performing a LDPC decoding operation to the LDPC data blocks; performing a bose-chaudhori-hocquenghen (BCH) data block check on decoded data of the LDPC data blocks; if all the BCH data block checks are failure, which means there are synchronization errors in the LDPC data blocks, switching the synchronization positions of the LDPC data blocks and receiving next data frame; otherwise ending synchronization determination of the LDPC data blocks if synchronization of the LDPC data blocks is correct. In the invention, misjudgments of synchronization positions of the LDPC data blocks caused by bad signals can be reduced.

Description

technical field [0001] The present invention relates to the field of signal reception of data communication systems, in particular to 32QAM (32Quadrature Amplitude Modulation, 32 Quadrature Amplitude Modulation) and 4QAM-NR ( 4 Quadrature Amplitude Modulation-Nordstrom Robinson, 4 quadrature amplitude modulation-Nordstrom Robinson quasi-orthogonal coding mapping) LDPC (Low-density Parity-check, low-density parity check) block synchronization method. Background technique [0002] In the coding and modulation of DTMB digital terrestrial broadcasting, the bit stream of the data source is firstly coded for forward error correction. Forward error correction coding is implemented by cascading an outer code (BCH code, Bose-Chaudhori-Hocquenghem Code) and an inner code (LDPC code, Low-density Parity-check Code, low-density parity-check code). 752-bit data encodes one BCH data block, and multiple BCH data blocks encode one LDPC data block. Then, the bit stream generated by the forw...

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Application Information

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IPC IPC(8): H04L7/00H04L1/00H04L27/38H04N7/26
Inventor 蒋朱成王晶汪涛马伟剑陈肯
Owner MAXSCEND MICROELECTRONICS CO LTD
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