Comparative analysis and performance of two predictive fade detection schemes for Ka-band fade countermeasures

The design of Ka-band satellite fade countermeasure (FCM) systems is condit ioned by the detection/prediction algorithm to be included within practical DSP-based FCM controllers. It depends upon the ability of systems to effic iently integrate the dynamic and stochastic nature of the Ka-band fading pr ocess which is dominated by rain attenuation and amplitude scintillation. T he paper analyzes the modeling and statistical performance of two predictiv e fade detection algorithms: Prediction is introduced as a way to minimize the impact of the finite response time on the BER/throughput of practical F CM systems, Both fixed (FDM) and variable (VDM) detection margin strategies are introduced and compared in terms of their margin requirements, FCM uti lization factor, and channel capacity utilization. The VDM is shown to be m ore efficient than its fixed counterpart. The long-term BER availability an d average user data throughput of a VDM/fixed-FEC/adaptive transmission rat e ECM are then evaluated for a typical low-power low-rate Ka-band in-bound VSAT link.