Sidelink CSI Reporting and MCS Control Through Layer 2 Relaying
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Solution Overview
Problem
Existing wireless communication systems, particularly in LTE and NR, face challenges in efficiently managing aperiodic channel state information (CSI) reporting and modulation and coding scheme (MCS) control for sidelink communications, which affects the optimization of transmission parameters and resource allocation.
Innovation Solution
Implementing aperiodic CSI reporting and MCS control through layer 2 relaying, where a relay user equipment (UE) transmits CSI requests and receives MCS indications from a base station to modulate sidelink communications, enabling efficient sidelink communication management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If aperiodic CSI reporting is implemented for sidelink communications, then transmission parameter optimization is improved, but device complexity increases
Solution Approach 1:
The relay UE acts as an intermediary between the destination UE and the base station. The relay UE receives the aperiodic CSI request from the base station, forwards it to the destination UE, receives the CSI report from the destination UE, and relays it back to the base station. This intermediary approach enables complex CSI reporting functionality while distributing the complexity across multiple nodes rather than concentrating it in one device.
Solution Approach 2:
The CSI reporting process is segmented into distinct functional stages: (1) base station generates and sends aperiodic CSI request, (2) relay UE forwards request to destination UE, (3) destination UE processes and sends CSI report, (4) relay UE forwards report to base station, (5) base station uses CSI for MCS determination. This segmentation allows each node to perform only its specific function, reducing individual device complexity while maintaining overall system capability.
2Productivity
If MCS control is implemented through layer 2 relaying, then communication efficiency is improved, but signal transmission complexity increases
Solution Approach 1:
The relay UE serves as a layer 2 intermediary that handles MCS control signaling. It receives MCS-related information from the base station, processes it according to layer 2 protocols, and applies appropriate modulation and coding schemes to sidelink transmissions. This intermediary function enables efficient MCS control while isolating the complexity of signal transmission management from the end devices.
Solution Approach 2:
The patent introduces a new dimension of control by implementing MCS management at the layer 2 relay level rather than directly at the physical layer or application layer. This dimensional shift in the protocol stack allows for more flexible and efficient control of sidelink communications, as the relay UE can adapt MCS parameters based on channel conditions and QoS requirements without requiring direct base station involvement in every transmission decision.
3Measurement precision
If relay UE forwards CSI requests and reports, then resource allocation optimization is improved, but loss of time in message transmission occurs
Solution Approach 1:
The relay UE is pre-configured with the necessary protocols and procedures for forwarding CSI requests and reports. The layer 2 relaying framework is established in advance, allowing the relay UE to immediately forward messages when requested without requiring setup or negotiation at the time of transmission. This preliminary configuration minimizes the time loss associated with message forwarding while maintaining accurate resource allocation based on CSI feedback.
Data Source
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AI summary
Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a relay user equipment (UE) may transmit an aperiodic channel state information (CSI) request to a UE, wherein the aperiodic CSI request is for sidelink communications; receive, from a base station, an indication of one or more modulation and coding schemes (MCSs) for sidelink communications between the relay UE and the UE based at least in part on transmitting the aperiodic CSI request; receive, from the base station, a communication to be relayed to the UE; and relay the communication to the UE via a sidelink communication that is modulated using an MCS of the one or more MCSs. Numerous other aspects are provided.