Polar Code CRC Interleaving for Low-Delay Wireless Encoding
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Solution Overview
Problem
In distributed CRC encoding for wireless communications, the existing systems face challenges in reducing encoding delay and false alarm probability when the information bit quantity is less than the maximum information bit quantity, due to high storage overheads and inefficient interleaving processes.
Innovation Solution
The proposed solution involves obtaining an interleaving sequence based on a system-supported maximum-length interleaving sequence, allowing for efficient interleaving operations by using either natural-order or reverse-order numbering, which reduces encoding delay and storage requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If a maximum-length interleaving sequence is stored to support the maximum quantity of information bits, then system storage overheads are reduced, but encoding delay increases due to extra calculation required when information bit quantity is less than maximum
Solution Approach 1:
The patent segments the maximum-length interleaving sequence into multiple sub-sequences based on the actual information bit quantity. Instead of using the full maximum-length sequence for all cases, the system divides it into appropriate segments that match the current data size, thereby reducing unnecessary calculation and encoding delay while maintaining support for variable information bit quantities
Solution Approach 2:
The patent dynamically adjusts the effective length of the interleaving sequence based on the information bit quantity parameter. By changing the parameter of sequence length from a fixed maximum value to a variable value that adapts to actual data size, the system optimizes both storage efficiency and encoding speed for different transmission scenarios
2Loss of time
If distributed CRC encoding is used to enable early termination capability, then decoding delay and energy consumption are reduced, but false alarm probability increases due to interleaving operations
Solution Approach 1:
The patent performs preliminary validation checks on the interleaving sequence before final CRC verification. By conducting preliminary checks on the distributed CRC bits after interleaving but before complete decoding, the system can detect potential false alarm conditions early and adjust the verification process accordingly, reducing false alarms while preserving early termination benefits
Solution Approach 2:
The patent implements a feedback mechanism where the results of partial CRC checks on interleaved distributed CRC bits are used to adjust subsequent verification steps. When early termination is triggered, the feedback from partial checks helps distinguish between genuine decoding failures and false alarms, thereby reducing false alarm probability while maintaining the speed advantages of early termination
Data Source
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AI summary
This application provides an encoding method and apparatus. The method includes: performing CRC encoding on A to-be-encoded information bits, to obtain a first bit sequence, where the first bit sequence includes L CRC bits and A information bits; performing an interleaving operation on the first bit sequence, to obtain a second bit sequence, where a first interleaving sequence used for the interleaving operation is obtained based on a system-supported maximum-length interleaving sequence and a preset rule, and a length of the first interleaving sequence is equal to A+L; or a second interleaving sequence used for the interleaving operation is the maximum-length interleaving sequence, a length of the second interleaving sequence is equal to Kmax+L, and Kmax is a maximum information bit quantity corresponding to the maximum-length interleaving sequence; and performing polar encoding on the second bit sequence. Therefore, during distributed CRC encoding, when an information bit quantity is less than the maximum information bit quantity, an interleaving sequence required for completing an interleaving process is obtained based on the system-supported maximum-length interleaving sequence.