Polar Channel Encoding Without Rate Matching for 5G Packets
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Solution Overview
Problem
Current channel encoding schemes, such as Turbo codes and LDPC codes, face challenges in supporting a wide range of bit rates with low complexity, particularly in 5G communication systems, especially for medium and short packet transmissions, and struggle with achieving ideal performance and reliability, especially in ultra-reliable and low latency communications.
Innovation Solution
The implementation of polar codes, which are proven to reach the Shannon limit with low encoding/decoding complexity, by determining a mother code length based on the channel load size to eliminate the need for rate matching, thereby reducing information transmission complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If Turbo codes or LDPC codes are used for channel encoding in 5G systems, then data transmission can be supported, but the encoding/decoding complexity becomes relatively high
Solution Approach 1:
The patent changes the fundamental parameter of the encoding scheme from Turbo codes or LDPC codes to polar codes. This parameter change enables the system to achieve comparable or superior transmission reliability while significantly reducing encoding/decoding complexity, as polar codes have inherently simpler structure and lower computational requirements
Solution Approach 2:
The patent segments the channel into multiple polarized channels with different reliability characteristics through the polar encoding process. By selecting and transmitting only on the most reliable polarized channels (information bit positions), the system achieves efficient transmission with reduced complexity compared to traditional approaches that treat all channels uniformly
2Adaptability or versatility
If rate matching is performed to match coded bits to channel load size, then transmission adaptability is improved, but encoding overheads and latency increase
Solution Approach 1:
The patent performs preliminary action by pre-determining the mother code length N of the polar code to exactly match the channel load size. This preliminary sizing eliminates the need for subsequent rate matching operations, thereby reducing encoding overheads and latency while maintaining transmission adaptability through the polar encoding process itself
3Adaptability or versatility
If Turbo codes are used for encoding, then existing LTE systems can maintain compatibility, but the codes cannot support extremely low or high bit rates
Solution Approach 1:
The patent changes the encoding scheme parameter from Turbo codes to polar codes, which fundamentally alters the bit rate support characteristics. Polar codes can naturally support extremely low and high bit rates by adjusting the information bit position selection, achieving reliable transmission at extreme bit rates where Turbo codes fail
4Device complexity
If polar codes are used with mother code length matching channel load size, then rate matching is eliminated, but encoding flexibility may be reduced
Solution Approach 1:
The patent introduces dynamics by allowing the mother code length N of the polar code to be flexibly determined based on the channel load size. This dynamic adaptation maintains encoding flexibility while eliminating rate matching, as the polar encoding process itself can be configured to match any required output length through appropriate selection of the mother code length
Data Source
AI summary
Embodiments of this application provide a channel encoding method for use by a communication device. The communication device obtains a quantity K of information bits, and determines a load size of a channel for transmitting the K information bits. The load size of the channel is N bits, where N≥K, N=2n, and n is a positive integer. The communication device performs a polar encoding process on the K information bits, to obtain a polar code sequence that includes N bits. The N-bit polar code sequence is transmitted using the channel, without rate matching. Because a quantity of coded bits obtained after the polar encoding is equal to a load size of a channel, no rate matching process is required. This reduces encoding overheads of a channel. Complexity and latency of channel encoding are greatly reduced, and performance loss associated with the rate matching operation is avoided.