Rateless Polar Coding for Incremental Redundancy Adaptation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing polar coding schemes require knowledge of code length before transmission, limiting flexibility and impacting reliability, and do not support fine-grained adaptation to varying channel conditions, especially in scenarios requiring incremental redundancy.
Innovation Solution
Implementing rateless polar coding with flexible encoding that outputs encoded bits in multiple segments, allowing incremental redundancy by varying starting positions and bit indices for predetermined values, enabling adaptive code length and rate adjustment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If code length is fixed before transmission in polar coding, then encoding reliability is improved, but flexibility and adaptability to varying channel conditions deteriorate
Solution Approach 1:
The patent implements rateless polar coding where the code length is not fixed beforehand but dynamically determined during transmission based on channel conditions. The encoder continuously transmits encoded bits until the decoder successfully recovers the original data, allowing the actual code length to adapt to varying channel quality without compromising encoding reliability.
Solution Approach 2:
The system changes the code length parameter dynamically during transmission. By using rateless coding, the effective code length becomes a variable parameter that adjusts according to channel conditions rather than being a fixed parameter, enabling both reliability and adaptability.
2Device complexity
If code rate is fixed in polar coding, then encoding simplicity is improved, but fine-grained adaptation to channel conditions deteriorates
Solution Approach 1:
The code rate becomes a dynamic parameter that adjusts automatically through the rateless coding mechanism. As the decoder successfully decodes more encoded bits, the effective code rate changes without requiring complex pre-calculation or reconfiguration, achieving fine-grained adaptation while maintaining encoding simplicity.
3Productivity
If code length is determined before transmission, then encoding efficiency is improved, but support for incremental redundancy deteriorates
Solution Approach 1:
The patent implements continuous encoding where the encoder generates encoded bits in a continuous stream without stopping or reconfiguring. This continuous action enables incremental redundancy by allowing the transmission to proceed with increasing code length until successful decoding, maintaining encoding efficiency throughout the process.
4Reliability
If polar coding uses fixed code construction, then decoding reliability is improved, but flexibility in code length and rate adjustment deteriorates
Solution Approach 1:
The polar code construction becomes dynamic in the rateless implementation. While the underlying polar coding structure maintains decoding reliability, the code length and rate parameters are no longer fixed but adapt dynamically based on decoding progress and channel conditions, achieving both reliability and flexibility.
Data Source
AI summary
Reduced numbers of encoded bits obtained by encoding input bits by a polar code are incrementally output, for transmission for example. The polar code comprises bit indices for placing bit values before encoding. The bit indices include a first set of bit indices for placing values of the input bits and a second set of bit indices for placing a predetermined bit value. A first reduced number of the encoded bits start from a first starting position, and a second reduced number of the encoded bits start from a second starting position different from the first starting position. The second reduced number of the encoded bits include one or more of the encoded bits not included in the first reduced number of the encoded bits. The reduced numbers of encoded bits may be output from continuous positions, in a circular buffer for example, or may include repeated bits.