Hybrid MIMO Architectures for Millimeter Wave Communications: Phase Shifters or Switches?

By Roi Méndez-Rial, Cristian Rusu, Nuria González-Prelcic, Ahmed Alkhateeb, Robert W. Heath. IEEE Access, 2015

829 citations recorded by the source corpus.

Hybrid analog/digital multiple-input multiple-output architectures were recently proposed as an alternative for fully digital-precoding in millimeter wave wireless communication systems. This is motivated by the possible reduction in the number of RF chains and analog-to-digital converters. In these architectures, the analog processing network is usually based on variable phase shifters. In this paper, we propose hybrid architectures based on switching networks to reduce the complexity and the power consumption of the structures based on phase shifters. We define a power consumption model and use it to evaluate the energy efficiency of both structures. To estimate the complete MIMO channel, we propose an open-loop compressive channel estimation technique that is independent of the hardware used in the analog processing stage. We analyze the performance of the new estimation algorithm for hybrid architectures based on phase shifters and switches. Using the estimate, we develop two algorithms for the design of the hybrid combiner based on switches and analyze the achieved spectral efficiency. Finally, we study the tradeoffs between power consumption, hardware complexity, and spectral efficiency for hybrid architectures based on phase shifting networks and switching networks. Numerical results show that architectures based on switches obtain equal or better channel estimation performance to that obtained using phase shifters, while reducing hardware complexity and power consumption. For equal power consumption, all the hybrid architectures provide similar spectral efficiencies.

Subfields: Electrical and Electronic Engineering

View Paper: https://www.semanticscholar.org/paper/c81da8262325c76d190fc89950fa64c779d9a8a1

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Citations in the corpus

A Comprehensive Survey on Millimeter Wave Communications for Fifth-Generation Wireless Networks: Feasibility and Challenges (2020, methodology): “For example, the phased-based architecture is compared to the switched-based architecture in [99], demonstrating a large performance gap of approximately 2 b/s/Hz in favor of phased-based architecture, in the realistic range of 1 − 7 RF chains.”
Dynamic Subarrays for Hybrid Precoding in Wideband mmWave MIMO Systems (2016, methodology): “The use of switches at mmWave and massive MIMO has been motivated by the work in [29]–[31].”
Beam Focusing for Near-Field Multi-User MIMO Communications (2021, methodology): “To alleviate this, hybrid analog/digital architectures are commonly considered for massive MIMO communications [18]–[20].”
Modeling and Analyzing Millimeter Wave Cellular Systems (2016, methodology): “To further reduce the power consumption, [106] and [117] proposed to replace”
Toward Millimeter-Wave Joint Radar Communications: A signal processing perspective (2019, background): “Thus, a feasible multiantenna Tx/Rx structure and its beamformers should be analog or hybrid (wherein the potential array gain is exploited without using a dedicated RF chain per antenna and phase shifter) [15] because fully digital beamforming is infeasible.”
Hybrid Beamforming for Massive MIMO - A Survey (2016, background): “The switching networks are also advantageous in comparison to full-complexity analog beamforming circuitries in terms of their cost and energy efﬁciency [32].”
Millimeter Wave Communications for Future Mobile Networks (2017, background): “The analog circuits of the hybrid architecture can be implemented by different circuit networks, leading to different hardware constraints [14], [115], [116].”
Channel Estimation for Hybrid Architecture-Based Wideband Millimeter Wave Systems (2016, background): “Due to the complicated structure of the sensing matrix, however, only a few special cases are considered in [13].”
Enabling Large Intelligent Surfaces With Compressive Sensing and Deep Learning (2019, background): “Estimating these channel vectors at the LIS, however, normally requires that every LIS antenna gets connected to the baseband processing unit through a fully-digital or hybrid architecture [23], [25], [33].”
A Survey on Hybrid Beamforming Techniques in 5G: Architecture and System Model Perspectives (2018, methodology): “It shows optimal points in EE-SE trade-off curves while considering the static power consumption (power dissipated in electronic components) for different number of RF chains and transmit antennas.”
Energy Efficient Multi-User MISO Communication Using Low Resolution Large Intelligent Surfaces (2018, background): “By assuming that each of these elements is actually a phase shifter, typical values of its consumed power are 15, 45, 60, and 78mW for 3-, 4-, 5-, and 6-bit resolution phase shifting [23], [24].”