Wideband Massive MIMO Beam Squint Compensation With Lens Subarrays
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Solution Overview
Problem
Existing methods for compensating the spatial-wideband effect in massive MIMO systems are either too complex, costly, or result in reduced array gain and spectral efficiency, making them impractical for next-generation wireless networks.
Innovation Solution
A transceiver design using lens antenna subarrays with analog filters and switches, replacing phase shifters, and employing a simplified exhaustive search to control beam squint, maintaining beam gain and reducing hardware complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If phase shifters and bandpass filters are added to compensate for spatial-wideband effect, then beamforming performance is improved, but hardware complexity and implementation cost increase
Solution Approach 1:
The patent extracts and removes the complex phase shifter and bandpass filter components from the beamforming system. Instead of using these traditional compensation mechanisms, the invention uses a simplified codebook design that achieves spatial-wideband effect compensation through algorithmic optimization rather than additional hardware, thereby reducing implementation cost and hardware complexity while maintaining beamforming performance
Solution Approach 2:
The patent changes the approach from hardware parameter adjustment (phase shifters) to codebook parameter optimization. By designing a codebook that accounts for spatial-wideband effects through mathematical modeling and optimization, the system achieves compensation without modifying physical hardware parameters, thus avoiding the complexity of additional phase shifters and filters
2Reliability
If codebook size is increased to guarantee minimum beam gain for all subcarriers, then beamforming performance is improved, but beamforming time and latency increase
Solution Approach 1:
The patent optimizes the codebook parameters to achieve a balance between codebook size and beamforming performance. By using mathematical optimization techniques, the invention determines the minimum necessary codebook size that guarantees minimum beam gain for all subcarriers while minimizing the number of codebook entries, thus reducing beamforming time and latency without sacrificing beam gain performance
3Device complexity
If fixed-size codebook is used to optimize beam pattern, then hardware complexity is reduced, but spatial-wideband effect compensation is insufficient
Solution Approach 1:
The patent optimizes the fixed codebook parameters specifically to account for spatial-wideband effects. By adjusting the codebook design parameters (such as beam spacing, coverage angles, and weighting factors) to compensate for frequency-dependent beam squint, the system achieves adequate spatial-wideband effect compensation with a fixed-size codebook, maintaining low hardware complexity while improving compensation performance
Solution Approach 2:
The patent incorporates spatial-wideband effect compensation into the codebook design phase itself. By pre-calculating and embedding compensation factors into the fixed codebook structure during system design, the invention enables the codebook to inherently account for spatial-wideband effects without requiring real-time adjustments or additional hardware, thus achieving compensation with a fixed-size codebook
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The design provides a spectrum-efficient and cost-effective solution that compensates for beam squint without performance loss, facilitating affordable and energy-efficient wireless networks.
Implementation Method 1
A transceiver design using lens antenna subarrays with analog filters and switches
Data Source
AI summary
This invention provides a novel transceiver design to control/compensate for the spatial-wideband effect in wideband massive multiple-input multiple-output (MIMO) systems for both sensing and communication networks. The proposed design aims to divide the ultra-wideband signal into narrow band beams and control them with a simplified exhaustive search-based precoding to align the beam angle to the target direction.