Polar Code Decoding Using Cyclic Shifts to Cut Sorting Latency
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Solution Overview
Problem
The increasing number of UEs and data volume in wireless communication systems necessitates efficient methods for using limited radio resources, particularly for high-density nodes and UEs, and there is a need to improve the performance of polar codes to reduce implementation complexity and latency.
Innovation Solution
A method involving cyclic shifting and successive cancellation decoding with a list size for polar codes, utilizing shift parameters and grouping operation values based on a predefined metric to optimize decoding performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If list successive cancellation decoding is used for polar code decoding, then decoding performance is improved, but implementation complexity and latency increase significantly due to sorting operations for each bit
Solution Approach 1:
The patent changes the parameter of decoding approach from conventional list successive cancellation decoding with sorting operations to parallel decoding without sorting. By modifying the decoding parameters and using cyclic shifting with parallel processing, the system achieves comparable or improved decoding performance while significantly reducing implementation complexity and latency.
Solution Approach 2:
The patent replaces the mechanical sorting operation in conventional decoding with a parallel decoding mechanism that uses cyclic shifting and simultaneous processing of multiple bit sequences. This substitution eliminates the need for complex sorting hardware while maintaining decoding effectiveness.
2Reliability
If list successive cancellation decoding is used for polar code decoding, then decoding performance is improved, but latency increases due to sorting operations for each bit
Solution Approach 1:
The patent employs periodic cyclic shifting of the bit sequence with a fixed shift parameter, replacing the iterative sorting process. This periodic action allows parallel processing of multiple bit sequences simultaneously, reducing the time required for decoding while maintaining performance.
Solution Approach 2:
The patent performs preliminary cyclic shifting of the bit sequence before decoding, preparing the data in advance for parallel processing. This preliminary action eliminates the need for time-consuming sorting operations during the actual decoding process, thereby reducing latency.
3Productivity
If the number of UEs and data volume increase in wireless communication systems, then communication capacity demand increases, but available radio resources remain limited
Solution Approach 1:
The patent creates an efficient decoding environment by using parallel processing and cyclic shifting techniques that maximize the utilization of limited radio resources. This approach allows the system to handle increased communication capacity demands without proportionally increasing resource consumption.
Data Source
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AI summary
This communication device may: generate P second bit sequences by cyclically shifting, on the basis of P different shift parameters, a first bit sequence obtained from a received signal; and determine a codeword by performing successive erase decoding of a list size L on each of the P second bit sequences. Each of the P different shift parameters satisfies the following. A predefined metric for a plurality of groups, which is determined on the basis of an index i of a weak bit from among N bits within the first bit sequence, is greater than a predetermined threshold value. The predefined metric is obtained by adding differences between the greatest and smallest operation values of each of the plurality of groups.