Multi-stream space shift keying modulation over MIMO channels

Abstract

Multiple-input multiple-output (MIMO) techniques take advantage of transmitting multiple data streams at the transmitter simultaneously to increase the spectrum efficiency. However, it is difficult for the newly emerging spatial modulation (SM) MIMO techniques to transmit multiple data streams directly, because of the multi-signal confliction problem. In this paper, we present a new multi-stream space shift keying (MSSK) modulation scheme for MIMO system, which modulates the multiple streams of signals to the transmitter by space shift keying (SSK) method without signal confliction. We adopt rotated signals to identify different streams and enlarge the Euclidean distance between streams without conveying any information. By smartly combining the rotated signals at the transmitter, the proposed MSSK modulation scheme is able to solve the multi-signal confliction problem in SSK system and increase the spectrum efficiency significantly. We also derive the tight upper bounds of bit error probability for MSSK and compare the proposed scheme with the existing SM MIMO schemes in this paper. Numerical results verify its effectiveness.