Fixed threshold on-off keying differential detection for satellite optical communications.

In this paper, on-off keying (OOK) differential detection with fixed threshold is proposed to deal with intensity fluctuation for satellite optical communications (SOCs). Since the intensity fluctuation is relatively slow compared to data rate, sequential symbols are in a quasi-stationary channel. Based on this characteristic, the proposed technique is implemented through the comparison between the difference of sequential symbols and the fixed threshold. The optimum fixed threshold is simply estimated with the knowledge of the channel model and noise power. The simulation results demonstrate that it overcomes the BER limitation of fixed threshold detection. Therefore, the proposed technique enables OOK detection with fixed threshold and real-time implementation in high-speed satellite optical communications.