Uplink HARQ-ACK and CSI Coding to Prevent CSI Dropping
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Solution Overview
Problem
In 3GPP LTE systems, simultaneous transmission of HARQ-ACK and CSI can lead to excessive CSI dropping, degrading downlink throughput due to timely CSI reports not being received by the eNB scheduler, especially in scenarios with steady downlink traffic requiring frequent HARQ-ACK information on the uplink.
Innovation Solution
A method for simultaneous transmission of HARQ-ACK and CSI involves separately encoding and transmitting these information bits at different power levels and using rate matching techniques to ensure reliable decoding, with HARQ-ACK bits prioritized for higher reliability, and CSI bits distributed across multiple slots to balance interference and error protection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If HARQ-ACK and periodic CSI are transmitted in the same subframe, then the uplink control information is complete, but the periodic CSI is dropped and downlink throughput degrades
Solution Approach 1:
The patent segments the uplink control information transmission by separating HARQ-ACK and CSI into different transmission opportunities. When HARQ-ACK needs to be transmitted, the patent uses PUCCH format 3 for reliable HARQ-ACK delivery, and schedules aperiodic CSI reports on PUSCH in subsequent subframes, thereby avoiding CSI dropping while maintaining complete control information flow.
2Productivity
If periodic CSI is dropped to prioritize HARQ-ACK transmission, then HARQ-ACK reliability is maintained, but downlink throughput degrades due to lack of timely CSI
Solution Approach 1:
The patent applies preliminary action by scheduling aperiodic CSI reports in advance on PUSCH resources that are allocated ahead of time. The eNB configures the UE with specific PUSCH resources for aperiodic CSI reporting, ensuring that CSI information is ready to be transmitted as soon as HARQ-ACK transmission is complete, thus maintaining downlink throughput without compromising HARQ-ACK reliability.
3Loss of time
If simultaneous transmission of HARQ-ACK and CSI is implemented, then transmission efficiency improves, but decoder failure rate increases
Solution Approach 1:
The patent uses PUSCH as an intermediary carrier for CSI transmission when HARQ-ACK is being sent on PUCCH format 3. By using PUSCH resources configured by the eNB for aperiodic CSI reporting, the patent avoids the interference and decoding conflicts that would arise from simultaneous transmission on the same channel, thus maintaining both transmission efficiency and decoding accuracy.
Data Source
AI summary
A method and user equipment for simultaneous transmission of a first set of information bits and a second set of information bits by a user equipment, either separately encoded utilizing transmit power or rate matching to increase successful decoding of a set of information bits, or jointly encoding using a priori knowledge or bit positioning to increase successful decoding. Also, the use of joint coding where a first set of information bits is encoded first and then encoded with a second set of information bits, and modulation symbol mapping are provided.