Polar Code Scrambling for Reliable PBCH Control Transmission
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Solution Overview
Problem
Current polar code implementation in 5G communications systems, particularly for the Physical Broadcast Channel (PBCH), faces challenges in encoding and decoding performance, especially in scenarios with poor channel quality, where existing methods struggle to ensure reliable transmission of control information.
Innovation Solution
The proposed solution involves using polar encoding and decoding methods, including Arikan, CA, and PC polar encoding, with rate matching and scrambling techniques to enhance the reliability and efficiency of control information transmission, specifically by fragmenting and scrambling encoded sequences using multiple scrambling sequences and performing modulation and mapping operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If polar code is used for PBCH encoding in 5G systems, then encoding and decoding performance should be improved, but in poor channel conditions, reliable transmission of control information cannot be ensured
Solution Approach 1:
The encoded sequence is segmented into multiple segments, and different scrambling sequences are applied to different segments. This segmentation allows the receiver to combine multiple received segments with different scrambling sequences to reconstruct the original information, improving reliability in poor channel conditions where some segments may be lost or corrupted.
Solution Approach 2:
Multiple scrambling sequences with different parameters are used to scramble different segments of the encoded sequence. By changing the scrambling parameters across segments, the system can maintain reliability when channel conditions vary, as different segments may be received at different times or under different channel states.
2Reliability
If multiple scrambling sequences are used to segment and scramble encoded sequences, then transmission reliability in poor channel conditions is improved, but signaling overheads increase
Solution Approach 1:
The same encoded information is copied into multiple segments with different scrambling sequences. Instead of transmitting additional signaling information about channel conditions or retransmission requests, the system creates multiple scrambled copies that can be independently received and combined, reducing signaling overhead while maintaining reliability.
3Reliability
If polar encoding is applied to PBCH, then channel coding performance is improved, but encoding and decoding complexity increases
Solution Approach 1:
The polar encoding process is segmented into multiple stages with different scrambling operations. By dividing the encoded sequence into multiple segments and applying different scrambling sequences, the overall complexity is distributed across multiple simpler operations rather than requiring a single complex decoding process, making the system more manageable while maintaining performance.
Data Source
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AI summary
This application discloses a transmission method, a transmission apparatus, and a communications device. The transmission method includes: performing polar polar encoding on a bit sequence, to obtain an encoded sequence, where the bit sequence includes control information and a cyclic redundancy check CRC sequence; fragmenting the encoded sequence, to obtain n encoded subsequences, where n is an integer, and n>0; and scrambling the n encoded subsequences by using n scrambling sequences respectively, to obtain n scrambled sequences. In the transmission method, the n scrambling sequences are newly defined based on encoding and decoding features of a polar code, and the n scrambling sequences additionally carry ┌log2n┐ -bit information. According to the foregoing encoding method, signaling overheads are reduced.