Open AccessComplex Quadrature Spatial Modulation
Author(s) -
Mohaisen Manar,
Lee Saetbyeol
Publication year - 2017
Publication title -
etri journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.295
H-Index - 46
eISSN - 2233-7326
pISSN - 1225-6463
DOI - 10.4218/etrij.17.0116.0933
Subject(s) - quadrature (astronomy) , quadrature amplitude modulation , mathematics , phase shift keying , modulation (music) , spatial modulation , transmission (telecommunications) , constellation diagram , algorithm , topology (electrical circuits) , channel (broadcasting) , optics , physics , computer science , acoustics , telecommunications , bit error rate , mimo , combinatorics , decoding methods
In this paper, we propose a spatial modulation ( SM ) scheme referred to as complex quadrature SM ( CQSM ). In contrast to quadrature SM ( QSM ), CQSM transmits two complex signal constellation symbols on the real and quadrature spatial dimensions at each channel use, increasing the spectral efficiency. To achieve that, signal symbols transmitted at any given time instant are drawn from two different modulation sets. The first modulation set is any of the conventional QAM / PSK alphabets, while the second is a rotated version of it. The optimal rotation angle is obtained through simulations for several modulation schemes and analytically proven for the case of QPSK , where both results coincide. Simulation results showed that CQSM outperformed QSM and generalized SM by approximately 5 dB and 4.5 dB , respectively, for the same transmission rate. Its performance was similar to that of QSM ; however, it achieved higher transmission rates. It was additionally shown numerically and analytically that CQSM outperformed QSM for a relatively large number of transmit antennas.