Three-Level Beamforming for Millimeter-Wave Hardware Complexity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current beamforming technologies in millimetric-wave communication face challenges such as high costs and power consumption due to the need for large quantities of ADCs/DACs, reduced flexibility in beam control, and inaccuracies in beam direction due to susceptibility to rain and atmospheric absorption, which complicates the achievement of high spectral efficiency and precision in beamforming.
Innovation Solution
A three-level structure beamforming method that includes a transmit-end and receive-end precoding module, intermediate-frequency beamforming module, and radio-frequency beamforming module, using feedback information to adjust beam direction and width, reducing the number of required ADCs/DACs and allowing gain adjustment through intermediate-frequency and radio-frequency port adjustments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a beamforming scheme based on digital precoding is used, then beam control precision is improved, but hardware cost and power consumption increase due to requiring a very large quantity of radio-frequency link ADCs/DACs
Solution Approach 1:
The patent divides the beamforming process into three distinct stages: baseband precoding, intermediate-frequency beamforming, and radio-frequency beamforming. Each stage processes a reduced dimensionality signal, so the total number of ADCs/DACs required is the sum of products of dimensions at each stage, which is significantly less than full digital precoding while maintaining beam control precision.
Solution Approach 2:
The patent introduces an intermediate frequency dimension between baseband and radio frequency. By performing beamforming operations in this intermediate dimension with reduced signal dimensionality, the system achieves the same beam control precision with fewer hardware resources, effectively solving the contradiction between precision and complexity.
2Device complexity
If a beamforming scheme based on analog phase shifters is used, then hardware cost is reduced, but beam control flexibility is reduced
Solution Approach 1:
The patent applies different processing qualities to different stages: baseband precoding uses full digital processing for maximum flexibility, intermediate-frequency beamforming uses hybrid processing for balanced flexibility and simplicity, and radio-frequency beamforming uses analog processing for hardware efficiency. This local differentiation resolves the contradiction between hardware simplicity and control flexibility.
Solution Approach 2:
The patent makes the beamforming system dynamically adaptable by allowing independent configuration of digital and analog components at each stage. The system can adjust the degree of digital vs. analog processing based on specific application requirements, providing flexibility while maintaining hardware efficiency.
3Device complexity
If a hybrid beamforming scheme based on digital and analog two-level-controller is used, then hardware cost is reduced compared to full digital, but beam direction accuracy deteriorates due to particular deviation in accuracy
Solution Approach 1:
The patent segments the beamforming control into three precise stages with progressively reduced dimensionality. By performing precise digital precoding at baseband followed by two stages of hybrid beamforming at intermediate and radio frequencies, the system accumulates precision across stages while maintaining hardware efficiency, overcoming the accuracy limitations of traditional two-level hybrid schemes.
Solution Approach 2:
The patent introduces an intermediate frequency stage as a mediator between baseband precoding and radio-frequency beamforming. This intermediate stage provides an additional degree of freedom for precise beam direction control, allowing the system to achieve high accuracy that compensates for the inherent limitations of hybrid analog-digital control.
4Productivity
If millimetric wave is used for communication, then spectral efficiency and transmission bandwidth are improved, but transmission loss increases due to susceptibility to rain and atmospheric absorption
Solution Approach 1:
The patent combines three beamforming stages (baseband precoding, intermediate-frequency beamforming, and radio-frequency beamforming) to achieve cumulative transmission gain. This merged approach provides sufficient transmission gain to overcome the high path loss and atmospheric absorption characteristics of millimetric wave propagation, enabling practical high-speed wireless communication.
Solution Approach 2:
The patent employs large-array beamforming with precise three-stage control to create highly focused directional beams. This concentrated beamforming approach maximizes the effective isotropic radiated power in the desired direction, compensating for the high free-space path loss and atmospheric attenuation of millimetric waves through directional concentration rather than omnidirectional spreading.
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
Embodiments of the present invention relate to the communications field, and provide a beamforming based communications method and apparatus, where a three-level structure is used to control a beam direction and a beam width while reducing use of hardware. The solution includes: obtaining, by a transmit end, a transmit-end precoding matrix TrBB, a transmit-end intermediate-frequency beamforming matrix TrIF, and a transmit-end radio-frequency-end beamforming matrix TrRF according to feedback information that is from a receive end; acquiring a first data stream, and performing precoding processing on the first data stream according to TrBB, to generate a first analog signal; performing weighting and power amplification processing on the first analog signal according to TrIF, to generate a second analog signal; performing weighting and power amplification processing on the second analog signal according to TrRF, to generate a third analog signal; and determining an antenna array matching the third analog signal, and transmitting the third analog signal to the receive end by using the antenna array matching the third analog signal.