LDPC Bit Shortening Patterns for Reliable Wireless Broadcasting
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Solution Overview
Problem
In communication/broadcasting systems, existing technologies face challenges in maintaining optimal performance when shortening or puncturing bits, particularly in LDPC codes, due to variations in channel noise, fading, and Inter-Symbol Interference (ISI), which affect data throughput and reliability.
Innovation Solution
The method involves determining zero-padding and puncturing patterns to optimize bit selection and processing in LDPC encoding and decoding, using Bose Chaudhuri Hocquenghem (BCH) encoding, and specific patterns for padding and puncturing bits to maintain performance, as defined in the Digital Video Broadcasting standards.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If bits are shortened or punctured in LDPC codes, then data throughput is improved, but reliability deteriorates
Solution Approach 1:
The patent applies preliminary action by pre-defining shortening and puncturing patterns that identify which bit positions should be shortened or punctured before actual transmission. These patterns are determined in advance based on channel conditions and code rate requirements, allowing the system to maintain optimal reliability while achieving the desired throughput by removing only the least critical bits.
Solution Approach 2:
The patent implements local quality by applying different treatment to different bit positions within the codeword. Instead of uniformly shortening or puncturing bits, the system selectively applies shortening and puncturing patterns that identify specific bit positions with lower importance. This allows critical bits to be preserved while non-critical bits are removed, maintaining reliability while improving throughput.
2Reliability
If zero-padding is applied to maintain codeword length, then reliability is improved, but device complexity increases
Solution Approach 1:
The patent applies preliminary action by pre-determining the positions where zero-padding should be applied through defined patterns. Instead of dynamically calculating padding positions during encoding, the system uses predetermined patterns that specify exactly which bit positions require padding, significantly reducing encoding complexity while ensuring codeword integrity is maintained.
Solution Approach 2:
The patent implements parameter changes by modifying the codeword structure through systematic zero-padding at specific positions defined by patterns. This changes the physical representation of the codeword while maintaining its logical integrity, allowing the system to achieve reliable transmission without complex real-time calculations.
3Reliability
If shortening and puncturing patterns are optimized, then data reliability is improved, but device complexity increases
Solution Approach 1:
The patent implements parameter changes by defining shortening and puncturing patterns as fixed parameter sets that can be selected based on channel conditions and code rate requirements. Instead of performing complex real-time optimization, the system chooses from pre-defined pattern parameters, reducing computational complexity while maintaining optimized reliability performance through systematic pattern selection.
Data Source
AI summary
An apparatus and method for transmitting and receiving data in a wireless communication is provided. The method includes determining a number of zero-padding bits, determining a number (Npad) of bit groups in which all bits are padded with zeros, padding the all bits within 0th to (Npad−1)th bit groups indicated by a shortening pattern with zeros, mapping information bits to bit positions which are not padded in Bose Chaudhuri Hocquenghem (BCH) information bits, BCH encoding the BCH information bits to generate Low Density Parity Check (LDPC) information bits, and LDPC encoding the LDPC information bits to generate a zero-padded codeword, wherein the shortening pattern is defined as an order of bit groups defined as 6, 5, 4, 9, 3, 2, 1, 8, 0, 7, 10 and 11.