Algorithms for the implementation of adaptive coding modulation on earth observation satellites

The paper discusses some algorithms for the imple­mentation of Adaptive Coded Modulation on Earth observation satellites. In the proposed system, the ground station (G/S) receiver estimates the downlink signal to noise ratio, and at time t 0 predicts the downlink signal to noise ratio that will affect the frame received at time t 0 + L, being L the overall system latency. Two different prediction techniques are analyzed, one suitable for short latencies and the other for long latencies. The G/S, from the predicted signal to noise ratio, chooses the ModCod scheme that the satellite will have to use at time t 0 + L and, if it is different from the previous one, sends a telecommand to the satellite to require a mode change. The paper shows the simulation results obtained by considering a realistic propagation model at 26 GHz, in terms of outage probability and throughput.