Extended quadrature spatial modulation for MIMO wireless communications Article uri icon

abstract

  • This paper presents an extended quadrature spatial modulation (EQSM) scheme that combines K quadrature spatial modulation (QSM) constellations to achieve a K-fold spectral efficiency (SE) enhancement. The idea underlying EQSM consists in using the average powers of the K QSM constellations as an additional dimension for the transmission of information bits. The modulation process starts with the design of a conventional QSM constellation. The remaining (K−1) QSM constellations are then configured with scaled amplitudes considering the same group of transmit antennas. The EQSM constellation is obtained by the superposition of the K scaled QSM constellations. A novel near maximum likelihood (ML) low-complexity algorithm for EQSM signal detection is also proposed in this paper. Analytical and simulation results obtained for independent and identically distributed (i.i.d.) Rayleigh fading channels show that the proposed EQSM scheme provides gains of up to 2.5, 5, 7, and 8 dB in bit error rate (BER) performance as compared to spatial multiplexing (SMux), double spatial modulation (DSM), conventional QSM, and spatial modulation (SM), respectively. In terms of detection complexity, EQSM allows a 67%25 complexity reduction when compared to SMux, and a 20%25 increase as compared to SM/QSM schemes. The obtained results also show that the proposed near ML detection algorithm reduces the complexity of the ML criterion by 82%25, while achieving near optimal ML performance. © 2018 Elsevier B.V.

publication date

  • 2019-01-01