Improving the performance of space shift keying (SSK) modulation via opportunistic power allocation

In this Letter, we show that the performance of Space Shift Keying (SSK) modulation can be improved via opportunistic power allocation methods. For analytical tractability, we focus on a 2 × 1 Multiple-Input-Multiple-Output (MIMO) system setup over correlated Rayleigh fading channels. A closed-form solution of the optimal power allocation problem is derived, and it is shown that the transmit-power of each transmit-antenna should be chosen as a function of the power imbalance ratio and correlation coefficient of the transmit-receive wireless links. Numerical results are shown to substantiate the analytical derivation and the claimed performance improvement.