LDPC Encoder Structure for Co-Channel Interference Reception
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current terrestrial TV broadcasting systems face co-channel interference issues, leading to white spaces and reduced spectrum efficiency, particularly in areas where frequency reuse is limited due to interference and lack of timing and frequency synchronization between overlapping signals.
Innovation Solution
A new Low Density Parity Check (LDPC) code with a length of 64800 and code rate of 4/15 is developed, utilizing an LDPC encoder and decoder that efficiently performs encoding and decoding using a specific sequence corresponding to a parity check matrix, enabling robust signal reception and demodulation in overlapping areas with co-channel interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If terrestrial TV broadcasting uses frequency reuse to improve spectrum efficiency, then spectrum efficiency is improved, but co-channel interference increases causing white spaces and reception failures
Solution Approach 1:
The patent applies parameter changes by optimizing the LDPC code rate (e.g., 3/15, 4/15, 5/15) and code length (e.g., 64800 bits) to achieve better error correction performance. By adjusting these parameters, the system can maintain reliable reception in co-channel interference environments while enabling more aggressive frequency reuse patterns, thus improving spectrum efficiency without sacrificing reception robustness
Solution Approach 2:
The patent uses composite coding structures combining systematic bits and parity bits in specific ratios (code rates), creating a composite code structure that balances information transmission and error correction capabilities. This composite approach allows the system to achieve both high spectrum efficiency and reliable reception by optimally combining different code components
2Reliability
If LDPC code length is increased to improve error correction performance, then reception robustness is improved, but encoding complexity and processing time increase
Solution Approach 1:
The patent segments the LDPC codeword into systematic bits and parity bits with specific length ratios (e.g., 45720 information bits and 19080 parity bits for 3/15 code rate). This segmentation allows the encoder to process data in structured blocks, reducing encoding complexity while maintaining the benefits of long code lengths for error correction
Solution Approach 2:
The patent provides multiple code rate options (3/15, 4/15, 5/15) and code length configurations, allowing the system to select optimal parameters that balance error correction performance with processing complexity. This enables flexible adaptation to different channel conditions and computational constraints
3Reliability
If LDPC code rate is decreased to improve error correction in interference environments, then reception robustness is improved, but data transmission efficiency decreases
Solution Approach 1:
The patent provides multiple code rate options (3/15, 4/15, 5/15) that allow the system to dynamically adjust the balance between error correction capability and transmission efficiency. In severe interference environments, lower code rates provide better robustness, while in better conditions, higher code rates improve throughput, enabling optimal adaptation to channel conditions
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 4/15. 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).