Polar Code Decoding with Symmetric Parameterization and Fixed Memory
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Solution Overview
Problem
Conventional techniques for decoding polar codes face challenges with increasing memory usage, which in turn increases calculation time, especially in list decoding processes.
Innovation Solution
A decoding device is implemented with an input unit for polar code-encoded code words, a computation unit that decodes the original message using conditional probabilities parameterized symmetrically, and an output unit for the decoded message. This approach reduces memory usage by employing symmetric parameterization and fixed address memory spaces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If conventional decoding techniques are used, then decoding functionality is achieved, but memory usage increases
Solution Approach 1:
The patent applies parameter changes by transforming the conditional probability parameters into a symmetric form. Specifically, the conditional probabilities P(0|y) and P(1|y) are converted into symmetric parameters θ that range from -1 to 1, where θ = 2P(0|y) - 1. This parameter transformation reduces the memory requirements while maintaining the decoding functionality, as the symmetric parameters can be stored more efficiently and allow for simplified computation in the decoding process.
2Loss of time
If memory amount increases, then decoding capability is maintained, but calculation time increases
Solution Approach 1:
The patent reduces calculation time by changing the parameters to symmetric form, which enables more efficient computation. The symmetric parameters θ allow for simplified arithmetic operations during decoding, reducing the computational burden. Additionally, the use of fixed address memory spaces with these transformed parameters minimizes memory access time, thereby reducing the overall calculation time required for decoding.
Solution Approach 2:
The patent segments the decoding process into distinct stages: parameter transformation, conditional probability computation, and final decoding decision. By dividing the decoding process and using fixed address memory spaces for different stages, the patent optimizes memory access patterns and reduces calculation time. The segmentation allows for parallel processing opportunities and reduces the critical path length in the decoding algorithm.
Data Source
AI summary
A decoding device includes a memory and a processor configured to execute inputting a code word encoded by a polar code from an original message; decoding the original message from the code word based on a conditional probability expressed by a symmetric parameterization and having observation information as a condition; and outputting the decoded original message.