Polar Code Transmission with Adaptive Mother Code Length
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Solution Overview
Problem
Existing wireless communication systems face challenges in achieving ideal performance for short packets and high reliability due to the complexity of turbo codes and LDPC codes, and require a new coding technology that can support wider coverage and more devices at low costs and complexity.
Innovation Solution
The implementation of polar code coding with a mother code length related to the quantity of sending times, which reduces retransmission requests and signaling overheads by optimizing polar code coding gain through rate matching and puncturing techniques.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If polar code coding is performed with traditional fixed mother code length, then coding implementation is simple, but coding gain is not fully utilized and transmission reliability is insufficient for wide coverage scenarios
Solution Approach 1:
The patent applies dynamics by making the mother code length adjustable rather than fixed. The base station dynamically configures different mother code lengths based on channel conditions and coverage requirements, allowing the system to adapt between short packet scenarios (smaller code length) and wide coverage scenarios (larger code length), thereby resolving the contradiction between reliability and complexity
Solution Approach 2:
The patent changes the parameter of mother code length from a fixed value to a configurable parameter. By modifying this parameter according to different transmission scenarios and indicating it to the terminal through signaling, the system achieves improved transmission reliability without excessive complexity increase, as the complexity only rises when larger code lengths are configured
2Reliability
If HARQ retransmission is used for wide coverage, then transmission reliability is improved, but signaling overheads increase due to repeated ACK/NACK messages
Solution Approach 1:
The patent applies preliminary action by pre-configuring the mother code length at the beginning of transmission based on predicted channel conditions and coverage requirements. This eliminates the need for multiple HARQ retransmissions and associated ACK/NACK signaling, as the initial transmission is optimized to succeed in wide coverage scenarios, thereby reducing signaling overhead while maintaining reliability
Solution Approach 2:
The patent converts the potential harm of increased coding complexity into benefit by using larger mother code lengths to achieve better error correction performance in wide coverage scenarios. This reduces the need for retransmissions, and the initial complexity investment prevents subsequent signaling overhead from multiple HARQ cycles
3Area of stationary object
If larger mother code length is used, then coding gain increases and coverage is extended, but signaling overheads increase for indicating code length
Solution Approach 1:
The patent merges the mother code length indication with existing downlink control signaling resources. By integrating this new information into already allocated signaling channels rather than creating separate dedicated signaling, the system extends coverage with larger code lengths while minimizing additional signaling overhead
Data Source
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AI summary
Embodiments of the present invention provide a data transmission method, including: performing polar code coding on to-be-coded bits, to obtain a mother code, where a code length of the mother code is related to K and Mi, i = 1,2,···,K, K is a quantity of sending times, Mi is a length of bits sent at an ith time, and K and Mi are positive integers greater than 1; performing rate matching on the mother code, to obtain to-be-sent bits, where a quantity of the to-be-sent bits is a sum of lengths of bits sent at K times; and sending the Mi to-be-sent bits at the ith time. A mother code that better meets an actual transmission requirement may be obtained by using the quantity of sending times during polar code coding, so that a polar code coding gain can be fully used. In addition, signaling does not need to be sent in real time to request retransmission, so that signaling overheads can be reduced.