Rate-Compatible Polar Codes for Robust HARQ Across Wireless Channels
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing polar code construction methods are not robust enough to handle variations in wireless channels and do not provide a universally good solution for arbitrary channels, making them unsuitable for practical applications, especially in HARQ transmissions where channel conditions can change.
Innovation Solution
A method and apparatus for constructing rate-compatible polar codes using a base code of short length with progressive puncturing, allowing for the generation of polar codes at different rates and lengths, and incorporating a two-step polarization process to preserve polarization and simplify hardware implementation, enabling efficient HARQ transmissions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If polar codes are optimized for transmission across a certain channel, then error rate performance is improved, but adaptability to channel variations deteriorates
Solution Approach 1:
The patent applies universality by designing a base polar code that can serve multiple channel conditions through progressive puncturing. The base code is constructed to be universally applicable, and by systematically puncturing it at different rates, it adapts to various channel variations without requiring separate optimized codes for each channel condition.
Solution Approach 2:
The patent implements dynamics through progressive puncturing, where the code rate can be dynamically adjusted by puncturing additional bits from the base code. This allows the system to adapt to changing channel conditions in real-time, transitioning from a static optimized code to a dynamic rate-compatible family of codes.
2Reliability
If polar codes are constructed for each specific channel condition, then error rate performance is improved, but device complexity increases
Solution Approach 1:
The patent applies segmentation by dividing the code construction process into two independent parts: (1) constructing a single base polar code of length 2^n, and (2) generating rate-compatible codes through systematic puncturing. This segmentation eliminates the need for complex construction algorithms for each code rate, reducing overall device complexity while maintaining good error rate performance.
Solution Approach 2:
The patent implements preliminary action by pre-construction of a base polar code that contains all the information needed to generate rate-compatible codes at any desired rate through puncturing. This preliminary construction eliminates the need for complex real-time code construction for each specific rate, significantly reducing computational complexity.
3Adaptability or versatility
If rate-compatible polar codes are constructed using traditional methods, then code rate flexibility is improved, but manufacturing precision deteriorates
Solution Approach 1:
The patent applies parameter changes by systematically varying the puncturing pattern based on the desired code rate. Instead of using arbitrary or complex puncturing patterns, the method changes parameters in a regular, predictable manner by puncturing additional bits from the base code according to a defined sequence, maintaining manufacturing precision while achieving rate flexibility.
Data Source
AI summary
A method, apparatus, and chipset are provided for constructing hybrid automatic repeat request (HARQ) rate-compatible polar codes for communication channels. The method includes constructing, in a terminal, a base polar code of length 2n; and determining a sequence of m<2n bits to puncture in the base polar code by testing a predetermined criterion at most (22n+2n)/2−1 times.