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

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

Rain granularity effects on bandwidth demand for faded DVB‐RCS systems

Broadband satellite communication networks, operating at Ka band and above, play a vital role in today's worldwide telecommunication infrastructure. The problem, however, is that rain can be the most dominant impairment factor for radio propagation above 10 GHz. This paper studies bandwidth and time slot allocation problem for rain faded DVB‐RCS satellite networks. We investigate how using finer rain granularity can improve bandwidth utilization in DVB‐RCS return links. The paper presents a mathematical model to calculate the bandwidth on demand. We formulate the radio resource allocation as an optimization problem and propose a novel algorithm for dynamic carrier bandwidth and time slots allocation, which works with constant bit rate type of traffic. We provide theoretical analysis for the time slot allocation problem and show that the proposed algorithm achieves optimal results. The algorithm is evaluated using a MATLAB simulation with historical rain data for the UK. Copyright © 2014 John Wiley & Sons, Ltd.