Polar HARQ Retransmission Bit Mapping by Redundancy Version
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Solution Overview
Problem
Current wireless communication systems, particularly those using Polar codes, lack specifications for selecting bits during hybrid automatic repeat request (HARQ) processes, especially in scenarios requiring data retransmissions, which can lead to inefficiencies and decoding failures due to insufficient resource allocation and signal quality issues.
Innovation Solution
The method involves defining Redundancy Versions (RVs) and selecting codeword bits based on Polar encoding techniques such as Shortening and Puncturing, with specific starting points for RV0 and RV1 determined by the code rate and bit positions, ensuring efficient data transmission and retransmission by selecting appropriate bits for transmission, including sub-block interleaving and XOR operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If Polar encoding is used for data transmission, then spectral efficiency and data rate are improved, but bit selection for retransmission becomes undefined leading to decoding failures
Solution Approach 1:
The patent changes the parameter of bit selection by defining specific starting points for different redundancy versions (RV0, RV1, RV2, RV3) based on Polar encoding characteristics. Each RV has a predetermined starting point position in the code bits, transforming the undefined bit selection into a controlled parameterized selection process that ensures successful decoding while maintaining high data rates
Solution Approach 2:
The patent performs preliminary action by pre-defining the starting points for all redundancy versions before transmission. The starting points are calculated in advance based on the Polar code structure and code rate, so that when retransmission is needed, the appropriate bits can be selected immediately without additional processing or negotiation, ensuring both efficiency and reliability
2Productivity
If redundancy versions are defined with specific starting points, then retransmission efficiency is improved, but system complexity increases due to additional bit selection logic
Solution Approach 1:
The patent simplifies the system by changing the approach from complex dynamic bit selection to simple parameter-based selection. The starting points are defined as straightforward parameters (e.g., first code bit, middle code bit, or specific positions like N/4, N/2, 3N/4) that can be easily calculated and implemented without complex logic
Solution Approach 2:
The system performs self-service by having both transmitter and receiver independently calculate the same starting points using the same rules based on code rate and Polar code structure. No additional signaling or coordination is needed between transmitter and receiver for bit selection, reducing overall system complexity while improving retransmission efficiency
3Reliability
If code bits are selected from different positions for retransmission, then data reliability is improved, but resource allocation becomes more challenging
Solution Approach 1:
The patent changes resource allocation from a complex optimization problem to a simple parameter-based assignment. Each redundancy version is assigned a specific starting point position (RV0: position 0, RV1: position N/4, RV2: position N/2, RV3: position 3N/4), transforming resource allocation into a straightforward parameter selection process that improves reliability without increasing complexity
Data Source
AI summary
Methods, systems, and devices related to wireless communication are described. A method of wireless communication includes determining respective starting points of data, in accordance with Polar encoding, that are associated with each Redundancy Version (RV) of a plurality of RVs and selecting data for transmission in accordance with at least one of the plurality of RVs.