64800-Length LDPC Encoder Using PCM Accumulation for Co-Channel Interference
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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 LDPC encoding methods.
Innovation Solution
A new LDPC codeword of length 64800 with a code rate of 3/15 is developed, utilizing an LDPC encoding technique that efficiently performs encoding using a sequence derived from a parity check matrix, specifically a circulant permutation matrix, to generate a systematic and parity part, enabling robust reception and frequency reuse in wireless channels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional terrestrial TV broadcasting is used, then transmission coverage is achieved, but co-channel interference occurs leading to white spaces and deteriorated spectrum efficiency
Solution Approach 1:
The patent applies parameter changes by optimizing the LDPC code with specific parameters (code length of 64800, code rate of 3/15, and specific parity check matrix structure) to achieve both reception robustness and spectrum efficiency. The modified PCM structure with dual diagonal matrix and identity matrix components enables the code to perform well in co-channel interference environments while improving spectrum reuse.
2Loss of energy
If frequency reuse is implemented to improve spectrum efficiency, then spectrum efficiency improves, but co-channel interference increases requiring more robust error correction
Solution Approach 1:
The patent converts the harmful effect of co-channel interference into a benefit by designing an LDPC code specifically optimized for co-channel interference environments. The code structure transforms the challenging interference condition into an opportunity to demonstrate superior error correction performance, enabling frequency reuse while maintaining reliability.
3Adaptability or versatility
If existing LDPC codes are used, then encoding can be performed, but the codes are not optimized for DVB broadcast standard or specific LDPC encoding methods
Solution Approach 1:
The patent applies local quality by tailoring the LDPC code parameters and structure specifically for the DVB broadcast standard. The code uses a localized optimization approach with specific parameters (N=64800, K=12960, code rate 3/15) and a customized parity check matrix structure that is optimized for the specific requirements of DVB broadcasting, rather than using generic LDPC codes.
Data Source
AI summary
A low density parity check (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 3/15. 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).