On Multi RF chain Time Successive SSK-M-ary Modulation Transmitter

Abstract

Space shift keying (SSK) is a modulation technique that conveys information using the indices of the activated antenna. Media Based Modulation (MBM) proposed recently uses the ON/OFF status of radio frequency (RF) mirrors to create distinct channel fade realizations with a single transmit antenna. Multi RF chain Time successive SSK-$M$-ary modulation (MRF-TSSM) is a new second-order transmit diversity scheme. The number of antennas needed at the MRF-TSSM transmitter increases exponentially with spectral efficiency as it uses SSK. To overcome this, two system models are proposed in this work. Generalized TSSM (GTSSM) uses the activation of antenna combinations to reduce the antenna count. The condition on the combination of antennas to achieve second-order transmit diversity, the bit error rate (BER) performance and its asymptotic form are derived for GTSSM. MBM based MRF-TSSM (MBM-TSSM) exploits MBM to realize the SSK phase of MRF-TSSM with one antenna per modulator. Further for MBM-TSSM, a mirror activation pattern (MAP) selection criterion is shown and its improved diversity order is analyzed. Simulation results are provided to validate all the analysis. From the results, it is found that GTSSM with a lesser number of active antennas performs better. Moreover, MBM-TSSM is found to provide the same performance as MRF-TSSM. Based on the number of MAPs used for selection, the diversity order of MBM-TSSM is also found to increase.