DMRS Virtual Antenna Port Design for Large Subcarrier Spacing
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Solution Overview
Problem
Existing wireless communication systems face challenges in efficiently utilizing large sub-carrier spacing for demodulation reference signals, particularly in scenarios with non-coherent or partially-coherent antenna ports, leading to reduced transmit power and reliability of data transmissions.
Innovation Solution
The proposed solution involves combining non-coherent or partially-coherent antenna ports into virtual antenna ports through precoding and cyclic delay diversity, allowing for improved channel estimation and data transmission by using a single virtual port for DMRS transmissions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If separate antenna ports are used for DMRS transmissions to multiple UEs, then spatial multiplexing capability is improved, but transmit power per port is reduced and reliability deteriorates
Solution Approach 1:
The patent combines multiple non-coherent or partially-coherent antenna ports into a single virtual antenna port for DMRS transmissions. This merging allows the base station to transmit DMRS signals to multiple UEs using the same physical antenna port, thereby concentrating transmit power on that port while maintaining the ability to serve multiple users through the virtual port abstraction.
2Stability of the object's composition
If transmit power is distributed across multiple antenna ports, then spatial diversity is improved, but power per port is reduced leading to lower signal quality
Solution Approach 1:
Multiple antenna ports are merged into a single virtual antenna port, allowing the system to maintain spatial diversity benefits while concentrating transmit power on the physical port, thereby improving signal quality without sacrificing diversity.
Solution Approach 2:
The virtual antenna port acts as an intermediary between the multiple physical antenna ports and the DMRS transmissions. It enables the system to manage power allocation and signal transmission in a way that preserves spatial diversity while ensuring adequate power per physical port for high signal quality.
3Quantity of substance
If multiple antenna ports are used for co-scheduled UEs, then user capacity is improved, but channel estimation accuracy deteriorates due to power reduction
Solution Approach 1:
The patent merges multiple antenna ports into a virtual antenna port for DMRS transmissions to co-scheduled UEs. This approach maintains user capacity by allowing multiple UEs to be served simultaneously while improving channel estimation accuracy through concentrated transmit power on the virtual port.
Data Source
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AI summary
Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment may receive a demodulation reference signal (DMRS) configuration that indicates a code-division multiplexing (CDM) group configured for the UE; receive a first indication of an antenna port, included in the CDM group, assigned to the UE for reception of a first set of DMRS transmissions; receive a second indication of whether a second set of DMRS transmissions for another antenna port, included in the CDM group, is present or absent for another UE; and perform channel estimation based at least in part on the first indication of the antenna port and the second indication of whether the second set of DMRS transmissions for the other antenna port is present or absent. Numerous other aspects are provided.