HARQ CQI Multiplexing Reducing Signaling Overhead
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Solution Overview
Problem
Current wireless communication systems face inefficiencies due to high signaling overheads, particularly in the transmission of channel quality indicators (CQI) during Hybrid Automatic Repeat Request (HARQ) operations, which limit spectral efficiency and reliability.
Innovation Solution
A method and apparatus for multiplexing and transmitting CQI with retransmission data using initial or retransmission uplink grants, where the transmission parameters for CQI are determined based on the initial uplink grant, allowing for reduced signaling overhead by aligning the CQI's Modulation and Coding Scheme (MCS) with the uplink data, thereby optimizing resource allocation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If CQI is transmitted separately during HARQ operations, then CQI transmission reliability is improved, but signaling overhead increases and spectral efficiency decreases
Solution Approach 1:
The patent combines CQI transmission with uplink data transmission by multiplexing CQI on the PUSCH channel. Instead of transmitting CQI separately on dedicated control channels, the system merges CQI with data packets, thereby reducing signaling overhead and improving spectral efficiency while maintaining transmission reliability through the same HARQ mechanisms.
2Measurement precision
If separate CQI transmission resources are allocated, then CQI transmission accuracy is improved, but device complexity and resource allocation overhead increase
Solution Approach 1:
The patent makes the PUSCH channel serve multiple functions: it carries both uplink data and CQI information. This multi-functional approach eliminates the need for separate dedicated CQI transmission resources, thereby reducing device complexity and resource allocation overhead while maintaining CQI transmission accuracy through proper modulation and coding scheme selection.
3Reliability
If HARQ retransmission is performed without CQI multiplexing, then retransmission reliability is improved, but signaling overhead increases
Solution Approach 1:
The patent merges CQI transmission with HARQ retransmission data on the same PUSCH channel. During retransmission, the system multiplexes CQI with the retransmitted data packets, allowing the base station to obtain channel quality information without requiring separate signaling messages, thereby reducing signaling overhead while maintaining retransmission reliability.
Solution Approach 2:
The patent maintains continuous channel quality feedback during the HARQ process by incorporating CQI transmission within the retransmission timeline. Instead of interrupting retransmission for separate CQI signaling, the system continuously obtains CQI information within the same transmission opportunity, eliminating idle signaling periods and reducing overall overhead.
Data Source
AI summary
A method of supporting Hybrid Automatic Repeat Request (HARQ) includes receiving an initial uplink grant on a downlink channel, transmitting uplink data on an uplink channel using the initial uplink grant, receiving a request for retransmission of the uplink data, determining at least one transmission parameter of a channel quality indicator (CQI) from the initial uplink grant, multiplexing retransmission data of the uplink data with the CQI, and transmitting the multiplexed data on the uplink channel. Amount of resources for transmission of the CQI is determined based on the at least one transmission parameter.