ABEP Performance of AF System Employing QSSK over IoT Network

Quadrature space shift keying (QSSK) modulation in cooperative communication, combined with cooperative relaying, improves the reliability in communication and enhances the overall spectral efficiency. Here, QSSK scheme is analyzed for complete uplink and downlink transmission system between a base station and a connected device for Internet-of-Things (IoT) application with dual-hop amplify-and-forward (AF) relaying systems using a single relay, multiple relays and relay selection techniques. Analytical expressions for cumulative distribution function (CDF) of the end-to-end signal-to-noise ratio are derived and used to evaluate the average bit error probability (ABEP) of QSSK modulation in mixed Rayleigh-Rician fading channel. The obtained ABEP expressions are in the form of Whittaker function which can be numerically evaluated using its numerical or series representation. Numerical and simulation results are presented to illustrate the impact of fading parameters on the system performance.