Joint Source-Channel Coding with Frozen Bits for Low-Overhead Decoding

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Solution Overview

Problem

Existing system-polar-based joint source-channel coding (JSCC) solutions in communications systems face high error detection probabilities due to the need for control signaling to convey probability distribution values, leading to increased overheads and decoding inefficiencies.

Innovation Solution

Determine frozen bit sequences based on the probability distribution of the information bit sequence, decouple pre-transformation operations from check bit sequence determination, and implement early decoding stopping using check bits to reduce error detection probabilities and improve decoding efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If control signaling is used to convey probability distribution values, then decoding accuracy is improved, but control signaling overheads increase

Engineering Contradiction:

Improvedecoding accuracyVSAvoidcontrol signaling overheads

Core Design Contradiction:

Measurement precisionVSQuantity of substance

Solution Approach 1:

The patent extracts the probability distribution information from control signaling and embeds it directly into the frozen bit sequences. This removes the need for separate control signaling to convey probability distribution values, thereby reducing overhead while maintaining decoding accuracy.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent performs preliminary encoding by determining frozen bit sequences based on probability distribution values before transmission. This preliminary action embeds the probability information into the code structure itself, eliminating the need for subsequent control signaling.

Inventive Principle:

Principle #10Preliminary action

2Quantity of substance

If probability distribution values are not conveyed to the decoder, then control signaling overheads are reduced, but error detection probability increases

Engineering Contradiction:

Improvecontrol signaling overheadsVSAvoiderror detection probability

Core Design Contradiction:

Quantity of substanceVSReliability

Solution Approach 1:

The patent performs preliminary determination of frozen bit sequences based on probability distribution values before transmission. This allows the decoder to use these pre-determined sequences for accurate decoding without needing explicit probability information, reducing overhead while maintaining reliability.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The frozen bit sequences serve as an intermediary that carries probability distribution information implicitly. Instead of directly transmitting probability values or using them as decoding parameters, the frozen bit sequences mediate the information transfer, enabling accurate decoding without explicit probability signaling.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Adaptability or versatility

If the decoder tries different probability distribution values sequentially, then decoding flexibility is maintained, but processing time increases

Engineering Contradiction:

Improvedecoding flexibilityVSAvoidprocessing time

Core Design Contradiction:

Adaptability or versatilityVSLoss of time

Solution Approach 1:

The patent performs preliminary determination of the correct probability distribution value by embedding it in the frozen bit sequences before transmission. This eliminates the need for the decoder to sequentially try different values, significantly reducing processing time while maintaining the ability to handle different probability distributions.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The frozen bit sequences provide feedback information about the probability distribution used during encoding. This feedback mechanism allows the decoder to immediately identify the correct probability distribution value without exhaustive search, reducing processing time while maintaining adaptability.

Inventive Principle:

Principle #23Feedback

4Reliability

If pre-transformation operations are performed on the information bit sequence, then source redundancy is better utilized, but decoding complexity increases

Engineering Contradiction:

Improvesource redundancy utilizationVSAvoiddecoding complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the pre-transformation operation with the channel coding process by determining frozen bit sequences based on the transformed information bit sequence. This integration reduces decoding complexity compared to performing separate transformation and decoding operations, while still utilizing source redundancy effectively.

Inventive Principle:

Principle #5Merging (Combining)

Data Source

PatentUS12413249B2Coding method, decoding method, and communications apparatus

Publication Date: 2025.09.09 HUAWEI TECH CO LTD

AI summary

This application provides coding/decoding methods and communications apparatuses thereof. In an implementation, a coding method includes: obtaining a first information bit sequence; determining a first frozen bit sequence based on a probability distribution value P1 of the first information bit sequence, determining a check bit sequence based on a second information bit sequence, where the second information bit sequence is the first information bit sequence or a sequence obtained after a pre-transformation operation is performed on the first information bit sequence, obtaining a first bit sequence based on the second information bit sequence, the check bit sequence, and the first frozen bit sequence, where the first bit sequence includes bits in the second information bit sequence.