Hybrid Beamforming Transmitter Modeling for Millimeter-Wave MIMO Applications

Abstract

Hybrid digital and analog beamforming is an emerging technique for high-data-rate communication at millimeter-wave (mm-wave) frequencies. Experimental evaluation of such techniques is challenging, time-consuming, and costly. This article presents a hardware-oriented modeling method for predicting the performance of an mm-wave hybrid beamforming transmitter. The proposed method considers the effect of active circuit nonlinearity as well as the coupling and mismatch in the antenna array. It also provides a comprehensive prediction of radiation patterns and far-field signal distortions. Furthermore, it predicts the antenna input active impedance, considering the effect of active circuit load-dependent characteristics. The method is experimentally verified by a 29-GHz beamforming subarray module comprising an analog beamforming integrated circuit (IC) and a 2 × 2 subarray microstrip patch antenna. The measurement results present good agreement with the predicted ones for a wide range of beam-steering angles. As a use case of the model, far-field nonlinear distortions for different antenna array configurations are studied. The demonstration shows that the variation of nonlinear distortion versus steering angle depends significantly on the array configuration and beam direction. Moreover, the results illustrate the importance of considering the joint operation of beamforming ICs, antenna array, and linearization in the design of mm-wave beamforming transmitters.

Issues, Challenges, and Research Trends in Spectrum Management: A Comprehensive Overview and New Vision for Designing 6G Networks

“…Conventional digital beamforming involves the complexity of large antenna arrays in addition to the increased cost of the system, whereas analog beamforming can handle only a single data signal at a time. Therefore, various low-cost and less complex hybrid precoding methods are required to model efficient transmitters and testbeds to mitigate jamming for MIMO-based mmWave systems [285][286][287][288][289]. This goal can be achieved by designing architecture with a combination of analog and digital processing that can be utilized to enable beamforming and spatial multiplexing with minimum complexity in achieving optimal performance [290,291].…”

Two-Dimensional Switchable Beam Transmitarray Antenna for mm-Wave Base Stations and Vehicular Networks

“…In literature, various beamforming prototypes using active phase shifters are reported [17][18][19][20][21] to validate the performance at mm-wave frequencies. A 8 x 4 uniform planar array antenna is used along with phase shifters and mixers in VOLUME 4, 2016 FIGURE 1.…”

“…The phase shifter-based 3-D hybrid beamforming prototype at millimeter-wave is presented in [18]. A 29 GHz hybrid beamforming IC, using phase shifters and a 2 x 2 patch antenna, is presented in [19]. The primary purpose of beamforming reported in [16][17][18] is to direct the radiation beams in different directions to multiple users.…”

A Digitally assisted nonlinearity suppression architecture using over‐the‐air beam cancelation

“…However, the experiments in this article did not discuss the case of strong nonlinear distortion. Most recently, an iterative algorithm is proposed to predict the far‐field radiation pattern and static nonlinear distortion of a mmWave hybrid beam‐forming transmitter 5 . However, it did not solve the problem of the varying nonlinear characteristics caused by the change of the beam direction.…”