Polar Code Encoding with Outer Subcodes for Faster Decoding
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Solution Overview
Problem
Existing polar code decoding algorithms suffer from high decoding delays and complexity, particularly when code rates approach 1 or ½, limiting throughput in communications systems.
Innovation Solution
The proposed method distributes information bits across outer-code subcodes, using a combination of algebraic and polar encoding to reduce decoding delays by employing classic decoding algorithms for intermediate code rates, while allowing parallel decoding for high and low code rates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If SC or SCL decoding algorithms are used for polar codes, then decoding performance is improved, but decoding delay increases
Solution Approach 1:
The patent divides the polar code decoding into multiple parallel paths by segmenting the code into different code rates. Some paths use SC/SCL decoding for high code rates while other paths use algebraic code decoding for low code rates, enabling parallel processing to reduce overall decoding delay while maintaining performance
Solution Approach 2:
The patent changes the decoding parameter by selecting different decoding algorithms based on code rate. For code rates ≥ 1/2, SC/SCL decoding is used; for code rates < 1/2, algebraic code decoding is used. This parameter-based selection optimizes the balance between decoding performance and delay
2Loss of time
If parallel decoding is used for outer-code subcodes, then decoding delay is reduced, but decoding complexity increases when code rate approximates 1/2
Solution Approach 1:
The patent applies different decoding strategies to different local regions (code rate ranges). For high code rates (≥1/2), parallel SC/SCL decoding is applied; for low code rates (<1/2), algebraic code decoding is applied. This local differentiation reduces complexity in the problematic 1/2 code rate region while maintaining parallelization benefits elsewhere
3Reliability
If all outer-code subcodes are decoded using polar decoding algorithm, then decoding performance is maintained, but throughput rate decreases
Solution Approach 1:
The patent changes the decoding algorithm parameter based on code rate to improve throughput. By switching from pure polar decoding to a hybrid approach where algebraic code decoding is used for low code rates and parallel SC/SCL decoding is used for high code rates, the system achieves higher throughput while maintaining performance through adaptive algorithm selection
Data Source
AI summary
Encoding methods and apparatuses are provided. The method includes: obtaining to-be-encoded information including K information bits and a mother code length N; determining, based on K and N, a set I corresponding to subchannels of the information bits, where information bits corresponding to subchannel sequence numbers in I are distributed in X outer-code subcodes including X1 first-type outer-code subcodes, quantities of information bits in the X1 first-type outer-code subcodes are P1, P2, . . . , and PX1, Pi (i=1, 2, . . . , X1) is one of K1, K2, . . . , and Km, which are greater than a first threshold LB and less than a second threshold HB, 1=<m<(HB−LB−1), LB+1<HB, HB<=a length B of an outer-code subcode, X, HB, and B are positive integers, and LB is an integer >=0; and performing encoding based on I.