Codeword Group Segmentation for HARQ Feedback Reliability
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Solution Overview
Problem
Current wireless communication systems, particularly in DC-HSDPA+MIMO systems, face challenges in reducing errors in HARQ ACK/NACK responses due to the limitations of single codeword groups for multiple transport blocks across dual carriers, which affects the reliability of feedback signaling.
Innovation Solution
The implementation of a method that selects a codeword group based on the number of transport blocks detected on each carrier and utilizes a single channelization code for composite HARQ ACK/NACK responses, improving the distance properties of codewords to enhance error detection and reduce errors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single codeword group is used for all HARQ ACK/NACK hypotheses across dual carriers, then device complexity is reduced, but error rate increases due to insufficient distance properties for diverse transport block scenarios
Solution Approach 1:
The patent segments the single codeword group into four distinct codeword groups (Group 0-3), each optimized for specific transport block detection scenarios on dual carriers. This segmentation allows each group to have tailored distance properties appropriate to its specific use case, thereby improving HARQ feedback reliability without requiring a single complex universal codeword group to handle all scenarios equally well
2Measurement precision
If multiple codeword groups are implemented for different transport block scenarios, then error detection capability is improved through optimized distance properties, but device complexity increases
Solution Approach 1:
The patent implements preliminary action by pre-defining four distinct codeword groups (Group 0-3) with optimized distance properties for different transport block scenarios before actual HARQ feedback transmission. Each group is pre-configured for specific scenarios (e.g., Group 0 for 1 TB on both carriers, Group 1 for 2 TBs on first carrier, etc.), allowing the UE to simply select the appropriate pre-prepared group based on detected transport blocks, thereby improving error detection precision while keeping the selection mechanism manageable
3Manufacturing precision
If codewords are optimized for specific transport block scenarios, then HARQ feedback accuracy is improved, but adaptability to different carrier configurations decreases
Solution Approach 1:
The patent achieves universality by designing a comprehensive four-group codeword system that collectively covers all possible transport block detection scenarios across dual carriers. Each codeword group is multi-functional in that it handles specific combinations of transport blocks on first and second carriers, and the system as a whole provides universal coverage for any carrier configuration scenario, maintaining high HARQ feedback accuracy across diverse situations
Data Source
AI summary
A method, an apparatus, and a computer program product for wireless communication are provided in which a single channelization code may be utilized on an uplink channel for providing a HARQ ACK/NACK response corresponding to DC-HSDPA+MIMO. Here, the set of channelization codes includes four codeword groups, each codeword group corresponding to a scenario wherein a node B schedules a single transport block or dual transport blocks on each of the two downlink carriers. Thereby, each of the four codeword groups may be designed to have an improved distance property in comparison to the utilization of a single codeword group for all HARQ ACK/NACK hypotheses, reducing errors.