Reduced Switching Connectivity for Large Scale Antenna Selection

Abstract

In this paper, we explore reduced-connectivity radio frequency (RF) switching networks for reducing the analog hardware complexity and switching power losses in antenna selection (AS) systems. In particular, we analyze different hardware architectures for implementing the RF switching matrices required in AS designs with a reduced number of RF chains. We explicitly show that fully-flexible switching matrices, which facilitate the selection of any possible subset of antennas and attain the maximum theoretical sum rates of AS, present numerous drawbacks such as the introduction of significant insertion losses, particularly pronounced in massive multiple-input multiple-output (MIMO) systems. Since these disadvantages make fully-flexible switching suboptimal in the energy efficiency sense, we further consider partially-connected switching networks as an alternative switching architecture with reduced hardware complexity, which we characterize in this work. In this context, we also analyze the impact of reduced switching connectivity on the analog hardware and digital signal processing of AS schemes that rely on received signal power information. Overall, the analytical and simulation results shown in this paper demonstrate that partially-connected switching maximizes the energy efficiency of massive MIMO systems for a reduced number of RF chains, while fully-flexible switching offers sub-optimal energy efficiency benefits due to its significant switching power losses.

On the Performance of Physically Constrained Multi-Pair Two-Way Massive MIMO Relaying with Zero Forcing

“…Moreover, there is no direct link between user pairs as assumption. Generally, massive MIMO system is assumed to be performed in a time-division duplexing (TDD) mode [11], [12] while in the same frequency band [13]. Therefore, we assume that the proposed system is modeled as spatially-correlated Rayleigh fading under TDD protocol and channel reciprocity works.…”

Efficient large scale antenna selection by partial switching connectivity

“…Moreover, although not explicitly shown here for reasons of space, the computation of P (T j ) is tractable for channels without correlation at the BS [1,24]. Intuitively, these probabilities can be derived by noting that the probability of finding the ordered statistic B B j i :N at a given antenna port is identical for all antennas when the above assumption is adopted, as detailed in [24].…”

A mixed-integer programming approach to interference exploitation for massive-MIMO

“…The selection can be performed according to several metrics, such as: received signal-to-noise ratio [9] and achievable capacity [10]. Recent works focused on antenna selection algorithms precisely designed for M-MIMO systems, since a direct application to M-MIMO is nearly prohibitive [11]- [13]. More specifically, [14] and [15] proposed the use of convex optimization for M-MIMO AS systems, for a massively distributed antenna system and for channel capacity optimization, respectively.…”