A MPR optimization algorithm for FSO communication system with star topology

In this paper, we introduce the multi-packet reception (MPR) technology to the outdoor free space optical (FSO) communication system to provide excellent throughput gain. Hence, we address two challenges: how to realize the MPR technology in the varying atmospheric turbulence channel and how to adjust the MPR capability to support as many devices transmitting simultaneously as possible in the system with bit error rate (BER) constraints. Firstly, we explore the reliability ordering with minimum mean square error successive interference cancellation (RO-MMSE-SIC) algorithm to realize the MPR technology in the FSO communication system and derive the closed-form BER expression of the RO-MMSE-SIC algorithm. Then, based on the derived BER expression, we propose the adaptive MPR capability optimization algorithm so that the MPR capability is adapted to different turbulence channel states. Consequently, the excellent throughput gain is obtained in the varying atmospheric channel. The simulation results show that our RO-MMSE-SIC algorithm outperforms the conventional MMSE-SIC algorithm. And the derived exact BER expression is verified by Monte Carlo simulations. The validity and the indispensability of the proposed adaptive MPR capability optimization algorithm are verified as well.