HARQ Rate Matching for Redundancy Version Bit Allocation
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Solution Overview
Problem
Current rate matching algorithms in wireless communications systems suffer from high bit dropout rates and decreased decoding performance, especially when the receiving station fails to interpret the header in one of the transmissions.
Innovation Solution
A rate matcher is implemented that generates multiple redundancy versions of encoded messages using a Turbo encoder and a hybrid automatic repeat request (HARQ) protocol, ensuring high decoding performance by strategically selecting systematic and parity bits for each transmission, and using loop logic for puncturing data bits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If known rate matching algorithms are used, then transmission is performed, but a high percentage of bits are not selected for transmission within a reasonable number of transmissions
Solution Approach 1:
The encoded message bits are segmented into different categories (systematic bits and parity bits) which are then selectively transmitted in different redundancy versions. This segmentation allows the rate matcher to strategically select which bits to transmit in each redundancy version, ensuring better distribution of transmitted bits across multiple transmissions and improving overall transmission efficiency and reliability.
2Productivity
If known rate matching algorithms are used, then transmission is performed, but decoding performance decreases drastically if the receiving station is not able to interpret the header
Solution Approach 1:
The rate matcher performs preliminary actions by strategically selecting and transmitting systematic bits in early redundancy versions before transmitting parity bits. This ensures that even if header interpretation fails or transmissions are interrupted, the receiving station has already received critical systematic bits that are essential for decoding, thereby maintaining decoding reliability under error conditions.
Solution Approach 2:
The system provides beforehand cushioning by ensuring that systematic bits are transmitted in the first redundancy version with high probability. This creates a safety cushion that protects against decoding failure even if subsequent transmissions are lost or headers are misinterpreted, as the essential systematic information has already been delivered.
3Reliability
If all systematic bits are transmitted in the first redundancy version, then decoding performance is improved, but the complexity of the rate matching algorithm increases
Solution Approach 1:
The rate matcher applies local quality by treating systematic bits and parity bits differently in the selection process. Systematic bits are given higher priority and are selectively transmitted in early redundancy versions, while parity bits are transmitted in subsequent versions. This localized differentiation simplifies the algorithm compared to exhaustive search methods while maintaining high decoding performance.
Data Source
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AI summary
Apparatuses and methods are provided for generating a plurality of redundancy versions using various rate matching algorithms. In some embodiments, a rate matcher is provided that allocates systematic and parity bits to the redundancy versions in a manner that allows all of these bits to be transmitted in at least one redundancy version. In some embodiments, the rate matcher uses a first puncturing algorithm to generate both a first redundancy version and a third redundancy version, but allocates a different proportion of the systematic bits to these redundancy versions. In these embodiments, the second redundancy version may include only bits that were not transmitted in the first redundancy version.