64800-Bit LDPC Encoder Segmentation for Co-Channel Broadcast Robustness
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Solution Overview
Problem
Current terrestrial TV broadcasting systems face co-channel interference issues, leading to white spaces where frequency reuse is not possible, resulting in deteriorated spectrum efficiency, and existing LDPC codes are not optimized for the DVB broadcast standard or specific encoding methods.
Innovation Solution
A new LDPC codeword of length 64800 with a code rate of 5/15 is developed, utilizing an LDPC encoding technique that efficiently generates codewords using a sequence derived from the sum of systematic and parity parts divided by a circulant permutation matrix size, specifically designed for terrestrial cloud transmission to improve spectrum efficiency and reception robustness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a new LDPC codeword with length 64800 and code rate 5/15 is designed, then spectrum efficiency and reception robustness are improved, but device complexity and encoding complexity increase
Solution Approach 1:
The LDPC codeword is segmented into a systematic part (21600 bits) and a parity part (43200 bits), with the parity part further divided into first parity bits (1440 bits) and second parity bits (41760 bits). This segmentation allows the encoder to process different portions with different complexity requirements, improving reception robustness through the structured parity bits while managing encoding complexity through modular processing.
Solution Approach 2:
The patent specifies precise parameters including codeword length (64800), code rate (5/15), systematic part length (21600), first parity part length (1440), and second parity part length (41760). These parameter changes define a specific LDPC code configuration that achieves optimal performance for terrestrial cloud transmission, balancing reliability improvements with manageable encoding complexity through standardized dimensions.
2Productivity
If LDPC encoding is performed using a sequence with number of rows equal to (systematic part length + first parity part length) / CPM size, then encoding efficiency is improved, but memory requirements increase
Solution Approach 1:
The sequence is pre-configured with a specific number of rows calculated as (21600 + 1440) / 360 = 64 rows, where 360 is the CPM size. This preliminary configuration of the sequence structure enables the encoder to efficiently process the systematic and first parity parts without requiring dynamic memory allocation during encoding, thus improving encoding efficiency while maintaining predictable memory requirements.
Data Source
AI summary
A low density parity check (LDPC) encoder, an LDPC decoder, and an LDPC encoding method are disclosed. The LDPC encoder includes first memory, second memory, and a processor. The first memory stores an LDPC codeword having a length of 64800 and a code rate of 5/15. The second memory is initialized to 0. The processor generates the LDPC codeword corresponding to information bits by performing accumulation with respect to the second memory using a sequence corresponding to a parity check matrix (PCM).