LDPC Transmission Coding Rate Adjustment With Known Bit Insertion
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Solution Overview
Problem
Current erasure correction codes face challenges in efficiently changing coding rates in response to varying communication quality, leading to increased circuit scales for encoders and decoders, which hinders transmission efficiency and erasure correction capability.
Innovation Solution
The method generates a low-density parity check convolutional code (LDPC-CC) with a coding rate of 1/3 by modifying parity check polynomials and inserting known information to adjust the coding rate, reducing the circuit scales of encoders and decoders.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the block length of Reed-Solomon code is increased to improve correction capability, then erasure correction capability is improved, but the amount of computation and circuit scale increase
Solution Approach 1:
The patent changes the fundamental parameter of the error correction code from Reed-Solomon to LDPC code, which has different structural characteristics. LDPC codes use a sparse parity-check matrix that enables efficient decoding algorithms with lower computational complexity and smaller circuit scale while maintaining or improving erasure correction capability, thus resolving the contradiction between correction capability and circuit complexity
Solution Approach 2:
The patent substitutes the algebraic structure of Reed-Solomon codes with the linear algebra-based LDPC code structure. This substitution replaces the polynomial-based encoding/decoding mechanism with a matrix-based sparse parity-check system, which fundamentally changes the computational approach and reduces the required circuit scale while preserving error correction functionality
2Adaptability or versatility
If multiple encoders with different coding rates are prepared to adapt to varying communication quality, then adaptability is improved, but device complexity increases
Solution Approach 1:
The patent introduces dynamic adaptability by enabling the LDPC encoder to adjust its coding rate based on communication conditions. Through mechanisms such as puncturing (selectively removing certain parity bits) and shortening (fixing certain information bits to known values), a single encoder configuration can dynamically produce multiple effective coding rates, eliminating the need for multiple fixed-rate encoders and reducing device complexity
Solution Approach 2:
The patent makes the LDPC encoder universal by designing it to handle multiple coding rates within a single unified structure. The encoder can function as different coding rates (e.g., 1/2, 2/3, 3/4) by applying different puncturing patterns or shortening configurations, allowing one encoder to perform the work of multiple specialized encoders, thus improving adaptability while reducing overall system complexity
Data Source
AI summary
A transmission apparatus includes a signal processing circuit configured to obtain information data bits to be transmitted; add known information data bits to the information data bits to generate first data blocks; perform error-correction coding on the first data blocks to generate first coded data blocks including parity data blocks such that the first coded data blocks satisfy a first code rate; remove the known information data bits from the first coded data blocks to generate second coded data blocks, the second coded data blocks satisfying a second code rate different from the first code rate; and modulate the second coded data blocks using a modulation scheme to generate a modulated signal, which is then transmitted. A number of the known information data bits depends on a number of the information data bits such that the first code rate is fixed regardless of the number of the information data bits.