16200-Length LDPC Encoder Using PCM Sequences for Frequency Reuse
Find Innovative SolutionsGenerate Solutions
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 16200 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 facilitate efficient encoding and decoding in a wireless channel, reducing memory requirements and improving spectrum efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a new LDPC codeword with length 16200 and code rate 3/15 is designed, then spectrum efficiency and frequency reuse capability are improved, but device complexity and encoding complexity increase
Solution Approach 1:
The LDPC codeword is segmented into a systematic part (3240 bits) and two parity parts (first parity part: 1080 bits, second parity part: 11880 bits). This segmentation allows the encoder to process different portions of the codeword using different strategies, reducing overall encoding complexity while maintaining the desired code rate and length
Solution Approach 2:
The patent employs a specific code rate (3/15) and codeword length (16200) that are optimized for the given application. By carefully selecting these parameters, the system achieves improved spectrum efficiency and frequency reuse capability while keeping the encoding complexity within acceptable limits for practical implementation
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 patent transforms the encoding problem from a direct bit-by-bit operation to a structured matrix operation using a sequence with a specific number of rows. This dimensional transformation allows the encoder to process multiple bits simultaneously through matrix multiplication, improving encoding efficiency while the structured nature of the sequence helps manage memory requirements
3Reliability
If the LDPC code is optimized for terrestrial cloud transmission, then reception robustness in overlap areas is improved, but adaptability to other broadcast standards deteriorates
Solution Approach 1:
The patent designs an LDPC code with length 16200 and code rate 3/15 that serves multiple purposes: it is optimized for terrestrial cloud transmission to improve reception robustness in overlap areas, while also being compatible with general DVB broadcast standards. The structured parity check matrix and systematic code design allow it to function effectively in both specialized and general broadcast scenarios
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 16200 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).