LDPC Bit Interleaving for Burst-Interference-Resistant Transmission
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Solution Overview
Problem
Existing LDPC codes struggle to effectively resist burst interference, which can lead to decoding failures and reduced system throughput.
Innovation Solution
The proposed solution involves interleaving certain bit sequences of the information bit sequence, parity bits with column weights greater than 1, and parity bits with column weights of 1, to disperse bits of different importance within the LDPC code, thereby reducing the impact of burst interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If LDPC code sends all information bits and corresponding parity bits during initial transmission, then the code rate is maintained, but burst interference can damage important bit information causing decoding failure
Solution Approach 1:
The patent segments the bit sequence into different types (information bits, parity bits with column weight > 1, parity bits with column weight = 1) and applies different interleaving strategies to each segment. This segmentation allows important bits to be dispersed differently from less critical bits, reducing the impact of burst interference on decoding reliability.
Solution Approach 2:
The patent introduces an additional dimension of protection by applying multiple interleaving operations. First, a first interleaver is applied to the entire bit sequence, then a second interleaver is applied specifically to parity bits with column weight greater than 1. This multi-dimensional interleaving approach ensures that burst interference cannot simultaneously affect all critical bits, thereby improving decoding reliability.
2Productivity
If LDPC code uses high bit rate check matrix with rich column weight distribution, then rate matching is supported, but importance of different bits varies making the system vulnerable to burst interference
Solution Approach 1:
The patent applies different local quality treatments to different bit types. Parity bits with column weight greater than 1 undergo a second interleaving operation specifically tailored to their importance, while other bits use the first interleaving. This local differentiation ensures that critical bits contributing to system throughput are adequately protected against burst interference while maintaining rate matching capability.
Solution Approach 2:
The patent performs preliminary interleaving operations before transmission, specifically applying the second interleaver to parity bits with column weight > 1 in advance. This preliminary action ensures that when burst interference occurs during transmission, the important bits are already dispersed in a pattern that minimizes damage, thereby protecting system throughput.
3Loss of energy
If LDPC code sends only new parity bit during retransmission, then incremental redundancy is achieved, but important bit information may have been damaged in initial transmission
Solution Approach 1:
The patent applies preliminary interleaving to disperse important parity bits before initial transmission. This preliminary action ensures that even if some bits are damaged during initial transmission, the retransmitted parity bits will be different from the originally damaged bits due to the interleaving pattern, allowing successful decoding after retransmission and maintaining retransmission efficiency.
Solution Approach 2:
The interleaving structure creates a feedback mechanism where the pattern of bit dispersion is known to both transmitter and receiver. When retransmission is needed, the receiver can leverage the known interleaving pattern to correctly interpret the retransmitted parity bits, improving decoding reliability after retransmission while maintaining incremental redundancy efficiency.
Data Source
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AI summary
A data transmission method, a data sending device, and a data receiving device are provided. The method includes: encoding, by a data sending device, information data by using a low-density parity-check LDPC code matrix, to obtain a bit sequence, where the bit sequence includes a first bit sequence, and the first bit sequence includes at least one information bit in the bit sequence; interleaving, by the data sending device, the first bit sequence to obtain a first interleaved bit sequence; performing, by the data sending device, modulation based on the first interleaved bit sequence to obtain a sending signal, and sending the sending signal; demodulating, by a data receiving device, a receiving signal to obtain a soft value sequence; and de-interleaving, by the data receiving device, the soft value sequence, to obtain a soft value sequence of a first bit sequence. This can improve a capability of an LDPC code resisting burst interference.