Polar Encoding with Puncturing and Permutation for Variable Code Lengths
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Polar codes are inflexible in terms of codeword length and inefficient in decoding, limiting their adaptability to varying channel conditions and throughput constraints.
Innovation Solution
A method and device that employ punctured shortened polar codes optimized for pre-selected modulation, allowing for variable codeword lengths and efficient decoding by selecting extension bits and applying permutation operations to minimize decoding errors, while maintaining low complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If polar codes are used with fixed length (integer power of two), then encoding complexity is low and decoding is efficient, but adaptability to varying channel conditions and throughput constraints is poor
Solution Approach 1:
The polar code is divided into multiple segments or blocks, each capable of independent encoding and decoding. This segmentation allows the code to be adapted to different channel conditions and throughput requirements by selectively activating or deactivating specific segments, thereby improving adaptability without proportionally increasing overall encoding complexity.
Solution Approach 2:
The code structure is made dynamic by allowing flexible configuration of code parameters such as code rate, block length, and freezing patterns based on real-time channel conditions and throughput constraints. This dynamic adaptability enables the system to optimize performance for varying conditions while maintaining relatively simple encoding operations through standardized polar code construction methods.
2Reliability
If concatenated codes with inner or outer polar codes are used to achieve better correction capability, then error correction capability is improved, but decoding complexity becomes too high
Solution Approach 1:
A carefully designed intermediate code structure is introduced that serves as a bridge between the inner and outer codes. This intermediate structure enables efficient decoding by reducing the computational burden of successive cancellation decoding while maintaining the error correction benefits of concatenated polar codes, thus improving reliability without proportionally increasing decoding complexity.
3Adaptability or versatility
If punctured or shortened polar codes are used to achieve variable lengths, then adaptability to different code lengths is improved, but error correction capability deteriorates
Solution Approach 1:
Freezing bits are predetermined and positioned in advance during code design to ensure that even when codes are punctured or shortened to achieve variable lengths, the remaining information bits maintain sufficient redundancy and structure for reliable decoding. This preliminary arrangement of frozen bits preserves error correction capability while enabling flexible code length adaptation.
Data Source
AI summary
Encoding devices and methods, arranged to execute encoding, wherein an input vector for polar encoding is computed, wherein the input vector comprises a set of information bits and a set of frozen bits, and an intermediate codeword is generated by executing a polar encoding of the input vector. Further, punctured and shortened bits are removed from the intermediate codeword, to obtain a reduced intermediate codeword, and an output codeword is generated by applying a permutation operation on the reduced intermediate codeword. A sequence of extension bits is selected from the intermediate codeword bits and information bits, and modulated symbols are generated by applying bitmapping on the output codeword and on the sequence of extension bits.