Beam-Space Channel Estimation Using Historical Beam Selection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current channel estimation methods in wireless communication systems, particularly in large antenna arrays, face challenges with low uplink signal-to-noise ratio (SNR) leading to inaccurate downlink beamforming, especially in non-line-of-sight scenarios, as they often discard or include unnecessary beam directions in channel estimation.
Innovation Solution
A method that utilizes historical data to select a subset of beam directions based on the likelihood of containing channel information, using beam space processing to enhance channel estimation accuracy without increasing power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If beam space processing is used to improve uplink SNR, then channel estimation accuracy improves, but the complexity of processing multiple beam directions increases
Solution Approach 1:
The patent extracts only the necessary beam directions for channel estimation by comparing historical beam data with current channel conditions. Instead of processing all available beam directions, the system identifies and processes only those beams that are likely to contain useful channel information, thereby reducing processing complexity while maintaining estimation accuracy.
Solution Approach 2:
The system performs preliminary analysis by storing historical beam direction data and channel information from previous measurements. This pre-computed information is used to predict which beam directions are most relevant for current channel estimation, allowing the system to prepare and prioritize processing of only the most important beams before actual estimation occurs.
2Measurement precision
If all beam directions are processed for channel estimation, then measurement completeness improves, but processing time and computational load increase
Solution Approach 1:
The patent extracts only the relevant beam directions from the complete set of available beams by comparing historical data with current channel conditions. This selective extraction ensures that processing is focused only on beams that are likely to contain useful channel information, reducing processing time while maintaining measurement completeness for the necessary directions.
Solution Approach 2:
The system performs partial processing by selecting a subset of beam directions based on historical likelihood rather than processing all beams. This partial action is sufficient to achieve accurate channel estimation without the excessive computational burden of processing every possible beam direction, especially in non-line-of-sight scenarios.
3Reliability
If codebook-based CSI feedback is used, then downlink beamforming information is provided, but feedback overhead increases with larger antenna arrays
Solution Approach 1:
The system uses self-service by having the user equipment transmit sounding reference signals that enable the base station to autonomously estimate the channel conditions. This eliminates the need for the UE to provide detailed CSI feedback about preferred beam directions, as the base station independently determines the channel state and optimal beamforming parameters from the uplink sounding signals.
Solution Approach 2:
Instead of the traditional approach where the UE provides feedback about downlink beamforming preferences, the patent inverts the process by having the UE transmit uplink sounding signals that allow the base station to estimate the downlink channel directly. This inversion leverages channel reciprocity to obtain downlink CSI information without requiring extensive uplink feedback from the UE.
Data Source
AI summary
One aspect of the disclosure provides a method for estimating a radio channel between a base station and a wireless device. The base station includes an antenna system which is configurable to utilize beam space processing for receiving radio transmissions. The method includes: using the antenna system to detect wireless energy from the wireless device in a plurality of beam directions; obtaining historical data relating to a likelihood that wireless energy in the plurality of beam directions contains channel information; selecting a subset of the plurality of beam directions based on the detected wireless energy and the historical data; and processing wireless energy detected in the subset of beam directions to estimate a channel between the base station and the wireless device.