Beamforming Gain Compensation for Wireless Channel Quality
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Solution Overview
Problem
Ultrahigh frequency wireless communication systems face challenges in maintaining performance due to channel multipath propagation reduction, terminal mobility, and channel condition changes, leading to sensitivity issues and propagation loss, especially in outdoor environments with Non-Line-of-Sight paths and obstacles.
Innovation Solution
A method for compensating beamforming gain differences by measuring and adjusting channel quality information, including CINR and RSSI, to optimize beamforming for both control and data channels, using a hybrid beamforming system that combines analog and digital techniques to adapt beam patterns and gains dynamically.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If beamforming is applied to maximize beamforming gain in ultrahigh frequency wireless communication, then propagation loss and penetration loss are reduced, but the system becomes sensitive to channel fading and obstacles due to strong directivity and reduced multipath propagation
Solution Approach 1:
The patent applies dynamics by making the beam pattern adaptable rather than fixed. The base station dynamically switches between first and second beam patterns with different beamwidths and beamforming gains based on channel conditions. When channel conditions are good, a narrower beam pattern with higher gain is used; when conditions deteriorate, a wider beam pattern with lower gain provides better coverage and robustness against fading and obstacles.
Solution Approach 2:
The patent changes key parameters of the beamforming system - specifically the beamwidth and beamforming gain - by switching between different beam patterns. This parameter adaptation allows the system to optimize performance for different channel conditions, reducing sensitivity to fading and obstacles while maintaining the benefits of beamforming gain.
2Reliability
If different beam patterns with different beamwidths and gains are operated for control and data channels, then channel quality is optimized, but beamforming gain difference arises in a particular direction according to the trade-off between beamwidth and beamforming gain
Solution Approach 1:
The patent implements feedback by measuring the actual beamforming gain in a particular direction and comparing it with the expected beamforming gain. Based on this feedback, the base station calculates compensation information and adjusts the transmit power or beamforming weights to compensate for the gain difference, ensuring that the actual channel quality matches the expected quality across different channels.
Solution Approach 2:
The patent applies counterweight by introducing compensation information that offsets the beamforming gain difference caused by using different beam patterns. This compensation acts as a counterbalancing mechanism that equalizes the effective beamforming gain across control and data channels, eliminating the unfair advantage or disadvantage that would otherwise arise from the beamwidth-gain trade-off.
3Measurement precision
If narrow bandwidth beamforming is operated with directivity to maximize beamforming gain in a particular direction, then sensitivity increases, but performance degrades in outdoor environments with mobility and Non-Line-of-Sight paths
Solution Approach 1:
The patent makes the beam pattern dynamic and adaptable to different environments. Instead of using a fixed narrow beam pattern that provides high sensitivity but poor adaptability, the system switches between narrow and wide beam patterns based on detected channel conditions. In outdoor environments with mobility or NLOS paths, the wider beam pattern provides better coverage and robustness while maintaining adequate sensitivity.
Solution Approach 2:
The patent changes the beamwidth parameter based on the operating environment. For indoor LoS environments, a narrow beamwidth is used to maximize sensitivity and beamforming gain. For outdoor environments with mobility or obstacles, the beamwidth is increased to provide broader coverage and maintain performance despite channel variations and NLOS conditions.
Data Source
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AI summary
A method of operating a Mobile Station (MS) in a wireless communication system using beamforming includes receiving a reference signal over a plurality of downlink transmit (Tx) beams, measuring channel quality information of the received reference signal, and generating effective channel quality information by compensating for beamforming gain compensation information according to the channel quality information.