Transmit Antenna Subset Selection for Single and Multiuser Spatial Modulation Systems Operating in Frequency Selective Channels

Abstract

Abstract-The extensive study of transmit antenna (TA) subset selection (TAS) in the context of spatial modulation (SM) has recently revealed that significant performance gains are attainable compared to SM systems operating without TAS. However, the existing TAS techniques conceived for SM were studied by considering a frequency-flat channel, which does not represent practical frequency-selective channels. In this paper, we address this open problem by designing TAS schemes for zero-padded single-carrier SM systems. Specifically, we employ a partial successive interference cancellation (SIC) receiver and invoke Euclidean distance based transmit antenna subset selection (ED-TAS) for each of the sub-channels. Furthermore, we show using theoretical analysis that the parallel sub-channels obtained are nearly identical, which enables us to employ majority logic decision to obtain a single TA subset to be used in all the subchannels. The computational burden is additionally reduced by restricting the number of sub-channels over which the ED-TAS technique is invoked. Furthermore, the proposed TAS schemes are extended to the multi-user scenario. The theoretical insights developed are validated using simulation results. Specifically, a signal-to-noise ratio (SNR) gain as high as 3dB is observed in the single user scenario and about 1dB in case of a two-user scenario upon employing our TAS.

Hierarchical Energy Efficient Hybrid Precoding for Configurable Sub-Connected MIMO Systems

“…The problem of RF chain selection can be expressed as finding a permutation matrix Π such that   eq 1 2 = H Π HH (23) where H1 contains the K most linearly independent columns in Heq (condition 1), or equivalently the best linear combination of H1 is close to H2 such that minz‖H1z− H2‖2 is sufficiently small (condition 2). Identifying the most important columns in a matrix has been studied in solving rank-deficient least square (LS) problems [47], information retrieval [48], genetics [49], and wireless communication [50].…”

Transmit Antenna Subset Selection in Generalized Spatial Modulation Systems

“…Since the number of active transmit antennas (TAs) is restricted, they suffer from the lack of transmit diversity. Several open-loop [9]- [12] and closed-loop techniques [13]- [24] were conceived in order to overcome this impediment. The closed-loop techniques can be broadly classified into a) modulation-order selection [13], b) TA-subset selection [14]- [24].…”

“…Several open-loop [9]- [12] and closed-loop techniques [13]- [24] were conceived in order to overcome this impediment. The closed-loop techniques can be broadly classified into a) modulation-order selection [13], b) TA-subset selection [14]- [24]. In [13], Yang et al studied a link-adaptive scheme based on modulation order selection, while both capacity based and Euclidean distance (ED) based transmit antenna selection (ED-TAS) schemes were proposed in [14].…”

“…In [22], Naresh et al studied the ED based mirror activation pattern selection schemes in the context of RF-mirror aided spatial modulation systems. A generalized transmit and receive diversity condition was proposed in [23] for MIMO systems based on the ED metric, while ED-TAS was studied in frequency selective channels for the first time in [24]. In [25], the authors have studied the benefits of TAS in secure communication in the presence of an eavesdropper.…”

“…1) The existing TA-subset selection algorithms [14]- [24] were mainly conceived for SM systems, where only a single TA is activated in each channel use. In this paper, we consider the generalized spatial modulation (GSM) system [3] employing ED-TAS, where multiple TAs are activated simultaneously.…”