Polar Code Length Selection for Low-Complexity Rate Matching

Solution Overview

Problem

Polar codes face challenges in rate matching, leading to increased complexity and overhead during encoding and decoding, particularly when adjusting code lengths from a mother code to a target code, which affects encoding gain and operational efficiency.

Innovation Solution

A method for rate matching in polar codes that involves selecting a mother code length based on preset conditions, either repeating or shortening/puncturing encoded bits to achieve the target code length, thereby reducing complexity and balancing encoding gain and complexity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If puncturing or shortening is used for rate matching to adjust code length from mother code to target code, then the target code length can be achieved, but additional overheads increase and complexity increases when large quantities of bits are shortened or punctured

Engineering Contradiction:

Improvecode length adjustmentVSAvoidencoding complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies dynamics by making the rate matching method adaptive based on code rate conditions. The system dynamically selects between repetition and puncturing/shortening methods according to whether the code rate is below or above a threshold, allowing the encoding process to adjust its behavior based on operational conditions rather than using a fixed approach

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of code rate threshold to determine the rate matching method. By comparing the actual code rate against a preset threshold, the system selects different encoding strategies, thereby optimizing performance based on the specific parameter values rather than using a single method for all conditions

Inventive Principle:

Principle #35Parameter changes

2Adaptability or versatility

If puncturing or shortening is used for rate matching to adjust code length from mother code to target code, then the target code length can be achieved, but additional overheads increase

Engineering Contradiction:

Improvecode length adjustmentVSAvoidoverhead

Core Design Contradiction:

Adaptability or versatilityVSLoss of substance

Solution Approach 1:

The patent changes the parameter of code rate threshold to determine the rate matching method. By comparing the actual code rate against a preset threshold, the system selects different encoding strategies, thereby optimizing performance based on the specific parameter values rather than using a single method for all conditions

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent applies dynamics by making the rate matching method adaptive based on code rate conditions. The system dynamically selects between repetition and puncturing/shortening methods according to whether the code rate is below or above a threshold, allowing the encoding process to adjust its behavior based on operational conditions rather than using a fixed approach

Inventive Principle:

Principle #15Dynamics

3Reliability

If mother code length increases to achieve lower code rate and higher encoding gain, then encoding gain increases, but complexity increases

Engineering Contradiction:

Improveencoding gainVSAvoidencoding complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies dynamics by making the rate matching method adaptive based on code rate conditions. The system dynamically selects between repetition and puncturing/shortening methods according to whether the code rate is below or above a threshold, allowing the encoding process to adjust its behavior based on operational conditions rather than using a fixed approach

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of code rate threshold to determine the rate matching method. By comparing the actual code rate against a preset threshold, the system selects different encoding strategies, thereby optimizing performance based on the specific parameter values rather than using a single method for all conditions

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS10341044B2Method for encoding information in communication network

Publication Date: 2019.07.02 HUAWEI TECH CO LTD

AI summary

Embodiments of the application provide a method for encoding data in a wireless communication network. A communication device obtains K data bits and a target code length M. The device determines a mother code length N1. The device encodes the K data bits to obtain an encoded bit sequence of code langth N1. The mother code length N1 is determined according to a minimum value of values Na, Nmax and N. The values Na, Nmax and N satisfy the following conditions: (1) the value Na satisfies with: a rate R1 is less than or equal to a preset rate, wherein the rate R1 is determined according to the value K and the value Na; (2) the value Nmax is a preset maximum mother code length, and Nmax is an integer power of 2; and (3) the value N satisfies with M≤N*(1+δ), and δ is a preset constant.