Joint Beam Pattern Training for 60 GHz WPAN Systems
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Solution Overview
Problem
60 GHz millimeter wave communication systems face challenges in determining a globally optimal beam pattern due to line-of-sight obstructions, which hinder performance and require complex hardware configurations, while existing beam training methods like alternate antenna weight vector training are susceptible to bias and do not efficiently exploit the beamforming gain in large-scale MIMO systems.
Innovation Solution
A method for joint training of beam patterns in a 60 GHz wireless personal area network (WPAN) system using a transmitter and receiver array, where both entities simultaneously try out different beam patterns, and a low-complexity antenna selection method that exploits the strong line-of-sight property, employing subspace-tracking-based adaptive beamforming and a low-rate feedback channel to inform the transmitter about preferred beams, thereby reducing hardware complexity and improving beamforming efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If alternate antenna weight vector training is used, then beam pattern training can be performed, but the method is susceptible to bias and does not efficiently exploit beamforming gain
Solution Approach 1:
The patent combines transmit and receive beam pattern training into a joint training process. Instead of alternating between training transmit and receive beams separately, both beam patterns are trained simultaneously by having the transmitter try different transmit beam patterns while the receiver tries different receive beam patterns, and they identify the combination that maximizes received signal power. This merging eliminates the bias inherent in alternate training and efficiently exploits beamforming gain.
2Reliability
If complex hardware configurations are used to overcome line-of-sight obstructions, then communication reliability improves, but device complexity increases
Solution Approach 1:
The patent employs dynamic beam pattern adjustment where the transmitter and receiver continuously adapt their beam patterns based on real-time channel conditions. The system dynamically selects from multiple beam patterns and adjusts beamforming weights to track the optimal communication path, allowing reliable communication through obstructions without requiring complex fixed hardware configurations.
Solution Approach 2:
The system changes beam pattern parameters (antenna weight vectors) adaptively based on channel state information. By varying the beamforming weights and selecting from different beam patterns, the system can overcome line-of-sight obstructions and maintain reliable communication without adding complex hardware, instead utilizing software-controlled parameter adjustments.
3Reliability
If exhaustive beam pattern search is performed to find globally optimal beam pattern, then beamforming performance improves, but training time increases
Solution Approach 1:
The patent uses preliminary sector sweep or initial beam alignment to quickly identify coarse beam directions before performing fine-tuned joint beam pattern training. This preliminary action narrows down the search space, allowing the system to find the globally optimal beam pattern faster without exhaustive search across all possible beam patterns.
Solution Approach 2:
The patent transforms the beam pattern search problem by having both transmitter and receiver simultaneously explore different beam patterns in parallel rather than sequentially. This dimensional change from alternating single-sided training to joint two-sided training reduces the overall training time while still achieving globally optimal beam patterns, as both sides converge together toward the optimal solution.
Data Source
AI summary
Systems and methods for joint training of beam patterns in a system having a transmitter and a receiver. Initial transmit and receive beam pattern vectors are first selected. The beam pattern vectors are perturbed to produce a plurality of perturbed transmit and receive beam pattern vectors. A received signal power between the transmitter and the receiver is estimated for each combination of the perturbed transmit and the perturbed receive beam pattern vectors. The transmit and receive beam pattern vectors having a highest received signal power are applied to the transmitter and the receiver respectively. The perturbation, estimation, and application steps are iterated until the received signal power meets a convergence criterion.