Quadrature Joint Transmitter-receiver Spatial Modulation

In this paper, we propose a multiple-input multiple-output (MIMO) communication technique called quadrature joint transmitter-receiver spatial modulation (QJSM) scheme, which extends the conventional joint transmitter-receiver spatial modulation (JSM) by including an additional degree of freedom to deliver the information. Specifically, in the proposed QJSM scheme, the in-phase and the quadrature components of the modulated symbols are separately transmitted and received, and the corresponding transmit and receive antenna indices convey additional spatial information. Therefore, the spectral efficiency in the spatial domain is twice than that of the conventional JSM scheme. Moreover, the proposed QJSM scheme also benefits from an enhanced system reliability. We derive the bit error ratio of the proposed QJSM system with the maximum-likelihood detection at the receiver. Numerical results show that the proposed QJSM scheme outperforms the conventional JSM scheme significantly in reliability when they have the identical antenna configuration and spectral efficiency.