Precoded Generalized Spatial Modulation for Downlink MIMO Transmissions in Beyond 5G Networks
; Velez, V.
; Farto, B.
Applied Sciences (Switzerland) Vol. 10, Nº 18, pp. 6617 - 6636, September, 2020.
ISSN (print): 2076-3417
Journal Impact Factor: 1,679 (in 2016)
Digital Object Identifier: 10.3390/app10186617
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The design of multiple input multiple output (MIMO) schemes capable of achieving both
high spectral and energy efficiency constitutes a challenge for next-generation wireless networks.
MIMO schemes based on generalized spatial modulations (GSM) have been widely considered
as a powerful technique to achieve that purpose. In this paper, a multi-user (MU) GSM MIMO
system is proposed, which relies on the transmission of precoded symbols from a base station to
multiple receivers. The precoder’s design is focused on the removal of the interference between users
and allows the application of single-user GSM detection at the receivers, which is accomplished
using a low-complexity iterative algorithm. Link level and system level simulations of a cloud
radio access network (C-RAN) comprising several radio remote units (RRUs) were run in order to
evaluate the performance of the proposed solution. Simulation results show that the proposed GSM
MU-MIMO approach can exploit efficiently a large number of antennas deployed at the transmitter.
Moreover, it can also provide large gains when compared to conventional MU-MIMO schemes with
identical spectral efficiencies. In fact, regarding the simulated C-RAN scenario with perfect channel
estimation, system level results showed potential gains of up to 155% and 139% in throughput and
coverage, respectively, compared to traditional cellular networks. The introduction of imperfect
channel estimation reduces the throughput gain to 125%.