Rate Matching Start Position Control for Stable HARQ Decoding
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Solution Overview
Problem
Existing rate matching methods in wireless communications systems, particularly in 5th generation mobile communications, result in poor Hybrid Automatic Repeat Request (HARQ) performance due to inefficiencies in bit sequence processing and decoding.
Innovation Solution
A method that determines the starting position of output bit sequences in a coded block, ensuring consecutive and non-repeated bits are sent, reducing decoding performance loss and improving decoding success rates by adaptively managing starting positions based on previous transmission data and code rates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If existing rate matching method is used, then the communications device can perform rate matching after channel coding, but HARQ performance is relatively poor
Solution Approach 1:
The patent implements dynamic selection of starting positions for output bit sequences based on previous transmission data and current code rates. The starting position k0(i) is adaptively determined using the formula k0(i) = (k0(i-1) + F(i-1)) mod NCB, allowing the system to dynamically adjust the bit sequence selection to optimize HARQ performance for each transmission instance rather than using a fixed pattern.
Solution Approach 2:
The patent performs preliminary calculation of starting positions k0(i) before actual transmission. By pre-determining the starting positions based on expected code rates and previous transmission states, the system prepares optimal bit sequence selections in advance, ensuring that consecutive and non-repeated bits are sent without requiring real-time adjustments during transmission.
2Productivity
If bit puncturing is performed to increase code rate, then code rate is increased, but decoding performance deteriorates
Solution Approach 1:
The patent changes the parameter of starting position k0(i) based on the code rate requirements. By adjusting k0(i) dynamically according to the target code rate and previous transmission state, the system can select different portions of the coded block for puncturing or repetition, optimizing the balance between achieving the desired code rate and maintaining decoding performance.
3Reliability
If bit repetition is performed to decrease code rate, then code rate is decreased, but transmission efficiency is reduced
Solution Approach 1:
The patent applies partial repetition by selectively repeating only the necessary number of bits to achieve the target code rate, rather than uniformly repeating all bits. The starting position k0(i) is adjusted to determine exactly how many bits need to be repeated, performing just enough action to meet the code rate requirement without excessive repetition that would reduce transmission efficiency.
4Reliability
If repeated bits are sent in retransmission, then HARQ combining is performed, but decoding performance is lost
Solution Approach 1:
The patent inverts the conventional approach by ensuring that retransmitted bit sequences do not contain repeated bits from previous transmissions. By calculating k0(i) to start from a position that follows the previous transmission's end position, the system sends complementary information rather than repeating the same bits, thereby avoiding decoding performance loss while still enabling effective HARQ combining.
Data Source
AI summary
This application discloses a method and an apparatus for processing information, a communications device, and a communications system. The communications device is configured to obtain a starting position of an output bit sequence in a coded block in a circular buffer, and determine the output bit sequence in the coded block based on a length of the output bit sequence and the starting position. A value of the starting position is one of {p0, p1, p2, . . . , pk<sub2>max</sub2>−1}, where 0≤pk<NCB, pk is an integer, k is an integer, 0≤k<kmax, NCB is a size of the coded block, and kmax is an integer greater than or equal to 4.