Sounding Reference Signal Port Grouping for Multi-Antenna UEs
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional NR technology does not provide a method for transmitting Sounding Reference Signals (SRS) using more than 4 antenna ports of a User Equipment (UE), which is inadequate for devices with increased antenna capabilities.
Innovation Solution
The method involves dividing UE antenna ports into two groups and applying distinct parameters such as group index, cyclic shift, time division multiplexing, and frequency division multiplexing to maintain orthogonality between SRSs transmitted over these groups, allowing for the generation and transmission of SRSs using multiple antenna ports.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional NR technology uses a fixed number of SRS antenna ports (typically 4), then the system complexity remains manageable, but the capability to support devices with large number of antennas (more than 4 antenna ports) is lost
Solution Approach 1:
The patent divides the SRS antenna ports into two distinct groups: first group antenna ports and second group antenna ports. Each group is configured with separate parameter sets (first set of parameters and second set of parameters), allowing the system to handle more than 4 antenna ports by segmenting them into manageable groups while maintaining orthogonality through group-specific configuration
Solution Approach 2:
The patent introduces a new dimension of differentiation by applying distinct parameter sets to different antenna port groups. Specifically, it uses different group indices, cyclic shifts, time division multiplexing configurations, and frequency division multiplexing configurations for the first and second groups, thereby expanding the system's capability beyond the conventional 4-port limit without proportionally increasing complexity
2Measurement precision
If more than 4 antenna ports are used for SRS transmission, then the channel state information estimation accuracy improves, but maintaining orthogonality between SRS signals becomes more difficult
Solution Approach 1:
The patent applies different parameter configurations to different antenna port groups to maintain orthogonality. The first group antenna ports use a first set of parameters while the second group antenna ports use a second set of parameters, allowing each group to be optimized locally for orthogonality maintenance while collectively supporting more than 4 antenna ports for improved channel estimation accuracy
Solution Approach 2:
The patent changes key parameters differently for the two antenna port groups, including group index, cyclic shift values, time division multiplexing timing, and frequency division multiplexing frequency allocations. These parameter changes ensure that SRS signals from different antenna ports remain orthogonal even when more than 4 ports are active, thereby maintaining measurement precision without excessive complexity
Data Source
AI summary
A method of communication in a cellular network is described. The method comprises determining Sounding Reference Signal (SRS) antenna ports of a user equipment configured for transmission of SRSs to a base station. The SRS antenna ports are divided into a first group of antenna ports and a second group of antenna ports when a number of antenna ports is greater than a predefined number of antenna ports. Orthogonality is maintained between the SRSs of the first group of antenna ports and the SRSs of the second group of antenna ports using one of a group index, a cyclic shift, time division multiplexing, and frequency division multiplexing. A first set of SRSs are transmitted over the first group of antenna ports and a second set of SRSs are transmitted over the second group on antenna ports.