LDPC Bit-Mapping Interleaving for Lower Wireless Error Rates
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Solution Overview
Problem
Existing communication and broadcasting systems using LDPC codes face challenges in minimizing signal distortion due to channel noises, fading, and Inter-Symbol Interference, particularly in high-speed digital communication systems, as conventional interleaving and bit-mapping schemes do not effectively utilize the unequal reliability characteristics of modulation signal-constituting bits.
Innovation Solution
The proposed solution involves an interleaving apparatus and method that improves LDPC codeword performance by using a parity check matrix to generate codewords, perform bit-mapping based on a predetermined table depending on the modulation scheme and coding rate, and optimize the relationship between codeword bits and modulation signal-constituting bits, thereby minimizing Bit Error Rate and Frame Error Rate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional interleaving and bit-mapping schemes are used, then the system structure is simple, but signal distortion due to channel noises, fading, and ISI cannot be minimized effectively
Solution Approach 1:
The patent applies local quality by differentiating the treatment of information bits and parity bits through separate interleaving processes. Information bits undergo one interleaving scheme while parity bits undergo another, allowing each type to be optimized independently for its specific reliability requirements and error correction needs
Solution Approach 2:
The patent segments the interleaving process into distinct stages: first interleaving information bits, then interleaving parity bits separately. This segmentation allows complex error protection to be achieved through multiple simpler, specialized interleaving operations rather than a single complex scheme
2Reliability
If LDPC codes are used for channel coding, then error correction capability is improved, but decoding complexity increases
Solution Approach 1:
The patent applies preliminary action by performing interleaving operations on codeword bits before modulation and transmission. This pre-processing organizes the bit sequence in advance to prevent burst errors, reducing the decoding burden and improving error correction efficiency during the actual decoding process
Solution Approach 2:
The patent introduces interleaving as an intermediary process between channel coding and modulation. This intermediate step transforms the codeword structure to distribute errors more uniformly, making the subsequent decoding process more efficient and less complex
3Productivity
If high-order modulation schemes are used, then data throughput is increased, but signal distortion and error rates increase
Solution Approach 1:
The patent applies parameter changes by systematically varying the interleaving depth, pattern, and segmentation parameters to optimize the balance between throughput and reliability. Different interleaving parameters are selected based on channel conditions and modulation scheme to minimize error rates while maintaining high data rates
Data Source
AI summary
Provided is a method for transmitting data in a communication or broadcasting system using a linear block code by generating a codeword by encoding input information data bits, interleaving the codeword; outputting modulation signal-constituting bits by bit-mapping the interleaved codeword using a bit-mapping table predetermined depending on a modulation scheme and a coding rate, outputting a modulation signal by modulating the modulation signal-constituting bits and transmitting the modulation signal via a transmit antenna.