PUCCH CSI and ACK/NACK Multiplexing via SC-FDMA Symbol Mapping
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Solution Overview
Problem
In the LTE-A system, the simultaneous transmission of CSI and ACK/NACK on PUCCH leads to a decrease in downlink throughput due to the need to drop CSI, and ACK/NACK bundling results in unnecessary data retransmissions and increased resource overhead.
Innovation Solution
The method involves selecting information from CSI and transmitting it together with hybrid automatic repeat request acknowledgement information and scheduling requests on the physical uplink control channel, using specific mapping and coding techniques to ensure accurate transmission of both CSI and ACK/NACK, thereby avoiding the need to drop CSI and reducing resource overhead.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If CSI is dropped when transmitting ACK/NACK on PUCCH, then ACK/NACK transmission is ensured, but downlink throughput decreases due to loss of channel quality information
Solution Approach 1:
The patent merges CSI and ACK/NACK transmissions by mapping both types of information onto the same PUCCH resources. Specifically, CSI bits are mapped to certain SC-FDMA symbols while ACK/NACK bits are mapped to other symbols within the same PUCCH format, allowing simultaneous transmission of both information types without dropping either.
Solution Approach 2:
The patent utilizes the time-domain dimension by differentiating resource allocation within the PUCCH structure. Different SC-FDMA symbols within the same PUCCH transmission are assigned to different information types (CSI vs ACK/NACK), effectively adding a temporal dimension to the multiplexing strategy.
2Quantity of substance
If ACK/NACK bundling is performed to transmit with CSI, then resource overhead is reduced, but unnecessary data retransmissions occur and throughput is influenced negatively
Solution Approach 1:
The patent applies local quality by treating different information types (CSI and ACK/NACK) with different mapping strategies within the same PUCCH transmission. Instead of uniform bundling, the system selectively maps CSI bits to specific SC-FDMA symbols and ACK/NACK bits to other symbols, preserving the integrity of individual bits while achieving efficient resource utilization.
3Device complexity
If all CSI is dropped when simultaneous transmission is needed, then PUCCH resources for ACK/NACK are sufficient, but base station cannot obtain downlink channel quality for accurate scheduling
Solution Approach 1:
The patent merges CSI and ACK/NACK transmissions by mapping both types of information onto the same PUCCH resources. Specifically, CSI bits are mapped to certain SC-FDMA symbols while ACK/NACK bits are mapped to other symbols within the same PUCCH format, allowing simultaneous transmission of both information types without dropping either.
Data Source
AI summary
The present invention discloses a method and a device for transmitting information on a physical uplink control channel (PUCCH). The method includes the following steps: a user equipment (UE) selects information from channel state information (CSI) to transmit (S1); the information selected from the CSI is transmitted on the PUCCH with one or both of hybrid automatic retransmission acknowledgment information and a scheduling request (S2), which enables a base station to obtain not only the information in the CSI but also one or both of the hybrid automatic retransmission acknowledgement information and the scheduling request from the PUCCH. The present invention avoids the problem of system downlink throughput degradation caused by dropping all CSI by the UE in the prior art, and avoids the problem that system downlink throughput is influenced by unnecessary data retransmission on a downlink carrier caused by ACK/NACK bundling among carriers.