Radio Node Precoder Determination for Beamforming
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing wireless communication network solutions for determining precoders for beamforming of reference signals are costly and computationally heavy, especially when using large numbers of antennas, and consume significant downlink resources, leading to inefficiencies and increased overhead.
Innovation Solution
A method where a radio node estimates the quality of a forward link channel based on reverse link reference signals to determine precoders for beamforming, reducing the reliance on channel quality feedback from the UE and optimizing the rank of precoders to minimize resource consumption, allowing for faster beamforming and improved network performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If full-dimension precoder reporting is used for beamforming with large numbers of antennas, then beamforming accuracy is improved, but downlink resource consumption and computational complexity increase significantly
Solution Approach 1:
The precoding process is divided into two stages: first, a reduced set of candidate precoders is selected based on simplified channel quality indicators; second, the final precoder is determined from these candidates using more detailed channel state information. This segmentation reduces the computational burden while maintaining beamforming accuracy.
Solution Approach 2:
Instead of using the complete channel state information for all precoder selections, the invention uses partial channel quality indicators (such as Rank Indicator and Channel Quality Indicator) to make preliminary precoder selections. This partial action approach reduces downlink resource consumption while achieving sufficient beamforming performance for most scenarios.
2Productivity
If the number of transmit antennas is increased to improve data rates and reliability, then MIMO channel performance is improved, but the overhead for reference signal transmission and precoder determination increases
Solution Approach 1:
The invention enables the same downlink reference signals to serve multiple functions: channel estimation for MIMO performance and precoder determination for beamforming. By making the reference signals multi-functional, the system achieves high data rates with large antenna arrays without proportionally increasing the overhead for precoder determination.
Solution Approach 2:
The system dynamically adjusts the rank parameter based on channel conditions and uses this adjusted parameter to determine the appropriate precoder. This parameter change approach allows the system to optimize the balance between data rate and overhead by selecting lower ranks when conditions permit, thereby reducing the number of reference signal resources needed while maintaining high productivity.
3Measurement precision
If channel quality feedback from UE is required for precoder determination, then precoder accuracy is improved, but the latency and complexity of the feedback loop increase
Solution Approach 1:
The network node determines a preliminary precoder using only downlink channel quality indicators (Rank Indicator and Channel Quality Indicator) before receiving detailed channel state feedback from the UE. This preliminary precoder can be applied immediately, reducing latency, while the system continues to refine the precoder selection using the feedback loop for accuracy-critical scenarios.
Data Source
AI summary
A method performed by a first radio node for determining one or more precoders for beamforming of reference signals is provided. The reference signals relate to Channel State Information, CSI, of a forward link channel from the first radio node to a second radio node. The first radio node receives (201) reverse link reference signals from the second radio node and estimates (202) a first quality value of the forward link channel based on the received reverse link reference signal. The first radio node then determines (203) one or more first precoders of respective one or more first ranks based on the reverse link reference signal and the estimated first quality value. When the one or more first precoders have been determined, the first radio node triggers (204) a first transmission of one or more first forward link reference signals to the second radio node. The one or more first forward link reference signals are beamformed according to the determined respective one or more first precoders.