Polar Code Rate Matching with Bit Channel Lookup and Interpolation
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Solution Overview
Problem
Polar code construction does not account for rate matching, leading to compromised gains and reduced throughput in wireless communication systems, as the number of bits generated by the polar code encoder may not match the desired code rate or codeword size, requiring additional processes like puncturing or shortening to adjust.
Innovation Solution
Implementing techniques that map transmission capacity factors to codeword lengths and number of transmitted bits using lookup tables or interpolation functions to determine bit channel locations for rate matching, allowing for selection between different rate matching schemes based on polar coding parameters and switching between them as needed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If polar code construction is performed without accounting for rate matching, then the encoding process is simpler, but the throughput and efficiency are reduced due to mismatched bit counts
Solution Approach 1:
The patent applies preliminary action by pre-calculating and storing bit channel locations for different code rates in lookup tables before actual transmission. This allows the system to quickly retrieve appropriate bit channel locations during rate matching without performing complex real-time calculations, thereby improving throughput while maintaining manageable coding complexity.
Solution Approach 2:
The patent changes parameters by using different bit channel location configurations from lookup tables based on the desired code rate. Instead of recalculating bit channel locations for each code rate, the system selects pre-computed configurations corresponding to different code rates, efficiently adapting to rate matching requirements while avoiding excessive computational complexity.
2Productivity
If lookup tables with pre-computed bit channel locations are used for rate matching, then rate matching efficiency is improved, but memory requirements increase
Solution Approach 1:
The patent applies segmentation by dividing the lookup table into multiple sections, each storing bit channel locations for specific code rates or code rate ranges. This segmentation allows the system to store pre-computed values efficiently in manageable segments rather than requiring a single large table, improving rate matching efficiency while controlling memory storage requirements through organized data structure.
3Adaptability or versatility
If interpolation functions are used to determine bit channel locations for code rates not in lookup tables, then adaptability is improved, but computational complexity increases
Solution Approach 1:
The patent uses interpolation functions as an intermediary mechanism to determine bit channel locations for code rates not explicitly present in lookup tables. By interpolating between known bit channel locations from the table, the system achieves smooth adaptation to arbitrary code rates without requiring exhaustive pre-computation for every possible code rate, balancing adaptability with computational complexity through this mediating approach.
Data Source
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AI summary
Methods, systems, and devices for wireless communication are described for polar coding with rate matching. A transmitter may construct input channels into a polar encoder to provide an information bit vector that does not include punctured or shortened bits. One or more transmission capacity factors may be used in identifying the information bit vector, which may be mapped to one or more of a codeword length of the polar code or a number of transmitted bits in each codeword. A number of different rate matching schemes may be available for transmissions, and may be selected based on one or more polar coding parameters. In some cases, mapping techniques may be used in two or more different rate matching schemes.