PBCH Polar Coding With CRC Placement by Subchannel Reliability
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Solution Overview
Problem
Current polar coding methods for physical broadcast channels (PBCH) in wireless communications systems do not fully optimize transmission reliability, as they do not effectively differentiate between various types of information bits based on their reliability, leading to suboptimal encoding and decoding processes.
Innovation Solution
A polar encoding method that maps cyclic redundancy check (CRC) bits to high-reliability positions and predictable information bits to low-reliability positions within the polar code, based on ascending order of subchannel reliability, to enhance the transmission reliability of broadcast signaling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If polar coding is applied to physical broadcast channel without differentiation of information bit reliability, then coding complexity is kept low, but transmission reliability is insufficient
Solution Approach 1:
The patent applies local quality by differentiating the reliability requirements of different information bits and assigning them to different subchannel positions accordingly. CRC bits are mapped to high-reliability subchannels while other information bits are mapped to lower-reliability subchannels, creating localized quality optimization without requiring complete redesign of the polar coding structure.
Solution Approach 2:
The patent changes the parameter of subchannel reliability assignment by introducing a specific mapping rule that considers the reliability characteristics of different information bits. This parameter change enables the system to optimize transmission reliability by aligning bit reliability requirements with subchannel reliability characteristics.
2Reliability
If all information bits are treated equally in polar encoding, then encoding process is simple, but critical information bits cannot be protected with higher reliability
Solution Approach 1:
The patent implements local quality by assigning different reliability levels to different information bits based on their importance. CRC bits, which are critical for error detection, are specifically mapped to high-reliability subchannels, while other information bits are mapped to subchannels with lower reliability requirements, thereby providing differentiated protection.
Solution Approach 2:
The patent applies preliminary action by pre-determining the reliability requirements of different information bits before the encoding process. The mapping rule is established in advance, specifying which subchannels should carry CRC bits and which should carry other information bits, thereby preparing the system for optimized reliability protection before actual transmission occurs.
3Reliability
If subchannel reliability is not considered in bit mapping, then mapping process is straightforward, but transmission errors increase
Solution Approach 1:
The patent applies local quality by considering the reliability characteristics of different subchannels when mapping information bits. The mapping rule specifically identifies high-reliability subchannels for CRC bits and assigns other information bits to subchannels according to their reliability characteristics, thereby optimizing overall transmission reliability through localized quality matching.
Solution Approach 2:
The patent changes the mapping parameter by introducing subchannel reliability as a key consideration in the bit-to-subchannel assignment process. This parameter change transforms the mapping from a simple sequential assignment to a reliability-aware assignment, improving transmission reliability while maintaining manageable mapping complexity.
Data Source
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AI summary
Embodiments of this application provide a method for coding in a wireless communication network. A communication device interleave a first bit sequence to obtain a first interleaved sequence having sequence number starting with a sequence number of 0, wherein the first bit sequence comprises bits for indicating timing, wherein the bits for indicating timing comprises a set of bits for indicating synchronization signal block index (SSBI); wherein the set of bits for indicating SSBI are placed in positions indicated by sequence numbers of 2, 3 and 5 in the first interleaved sequence. The devices then add d a first CRC bits on the first interleaved sequence to obtain a second bit sequence, then interleave on the second bit sequence according to an interleave pattern to obtain a second interleaved sequence, and finally polar encode the second interleaved sequence to obtain the encoded sequence.