Dynamic Frozen Polar Codes for Adaptive 5G Control Channels

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Solution Overview

Problem

Current wireless communication systems, particularly in 5G networks, face challenges in optimizing error correction for control channels due to the static nature of frozen bits in polar codes, which does not adapt well to varying channel conditions, leading to suboptimal performance across different service requirements and channel states.

Innovation Solution

The implementation of dynamic frozen polar codes, where some frozen bits have values dependent on information bits, allowing for adaptive error detection and correction based on channel reliability, enhancing encoding and decoding efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If static frozen bits are used in polar codes, then the encoding structure is simple, but the error correction performance is suboptimal under varying channel conditions

Engineering Contradiction:
Improveerror correction performanceVSAvoidadaptability to channel conditions
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent applies dynamics by making frozen bit values dependent on information bits rather than static. Specifically, frozen bits are determined as functions of information bits (e.g., u_i = f(u_0, u_1, ..., u_{i-1})), allowing the code to adapt to varying channel conditions and service requirements while maintaining the polar code structure

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of frozen bit values from fixed constants to dynamic values based on information bits. This parameter change enables the same polar code structure to achieve different error correction performances under different channel conditions by varying the frozen bit values according to the information bits

Inventive Principle:
Principle #35Parameter changes

2Reliability

If different frozen sets are used for different channel states, then error correction performance is improved, but memory cost and complexity increase

Engineering Contradiction:
Improveerror correction performanceVSAvoidmemory cost
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Instead of storing multiple frozen sets for different channel states, the patent changes the approach by generating frozen bit values dynamically through functions of information bits. This reduces memory requirements while maintaining adaptability to different channel conditions

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The system uses the information bits themselves to generate the frozen bit values through deterministic functions. This self-service approach eliminates the need for external storage of multiple frozen sets, reducing memory cost while maintaining the ability to adapt to different channel states

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP3568920B1Dynamic frozen polar codes
Publication Date: 2024.12.11 QUALCOMM INC
  • EP3568920B1 patent drawingFigure 1
  • EP3568920B1 patent drawingFigure 2
  • EP3568920B1 patent drawingFigure 3

AI summary

Certain aspects of the present disclosure generally relate to wireless communications and, more particularly, to methods and apparatus for dynamic frozen polar codes, for example, for control channels. An exemplary method may be performed at the encoder. The method generally includes encoding a stream of bits using a polar code. The encoding includes selecting a first set of channel indices for encoding information bits. The encoding includes selecting a second set of the channel indices smaller than a channel index for a first information bit for encoding fixed frozen bits. The encoding includes selecting remaining channel indices for dynamic frozen (PCF) bits having values based on one or more of the information bits. The method includes transmitting the encoded stream of bits.