Threshold Forwarding Protocol of Cooperative LEO Satellites Communication System

In order to improve the reliability of low-earth-orbit (LEO) satellite communications, in this paper, we propose a forwarding protocol for cooperative LEO satellites communication system, called threshold-and-forward protocol. Note that multi-satellites can receive and forward the user's signal. After one satellite receives the signal, it compares the power of the signal with a given threshold value. If the signal is higher than the threshold value, the signal is limited to a given value. Otherwise, it is linearly processed and forwarded to the receiver. Receiver combines the signal from different satellites and tries to decode it. The P.D.F. of signal with different forwarding protocols are analyzed. Simulation results show that the performance of the proposed forwarding protocol outperforms the existing forwarding protocols such as amplify-and-forward, demodulate-and-forward and estimate-and-forward in the multi-satellites cooperative scenario.