On the performance of space modulations over κ-μ fading channels with imperfect CSI

Space modulation techniques, such as spatial modulation (SM) and space shift keying (SSK), are spatial multiplexing MIMO techniques that use multiple transmit- and receive-antenna in a new and resourceful fashion to enhance the overall spectral efficiency of wireless communication systems. In this paper, the performance of space modulations over the generalized κ-μ fading channels under imperfect channel state information (CSI) is analyzed. In particular, a generalized, simple and exact closed-form expression for the pairwise error probability (PEP) of SM- and SSK-MIMO systems that operate over the generalized κ - μ fading channels is derived and evaluated. The PEP expression jointly considers the envelope-phase distribution of the fading channel. Based on the derived PEP and the union bound technique, a closed-form expression for the average bit error rate (BER) is obtained. The system performance is analyzed and discussed through representative numerical examples over a wide range of the fading parameters (κ and μ) and under the channel estimation error. The numerical results are corroborated with Monte-Carlo simulations to validate our analytical results.