Information Theoretic Capacity Bounds for Protected SATCOM

Fast frequency hopped spread-spectrum is used in military satellite communication systems for providing resilience to different types of jamming. Most analyses focus either on the worst case jamming to obtain performance metrics such as Bit Error Rate (BER), or use specific waveforms and evaluate system performance by means of simulations. Recently there has been a growing interest in using Adaptive Coding and Modulation (ACM) and tune the modulation and coding to specific jamming scenarios, in order to maximize system throughput. This paper provides information theoretic bounds for such systems with wide-band and pulse jammers. Developing these bounds also provide insight into how to construct waveforms which maximize system capacity, while providing the desired jamming resistance. Since fast frequency hopped spread-spectrum systems also typically use Time Division Multiple Access (TDMA), there is synchronization overhead. So, information theoretic bounds for capacity, where the transmitter and receiver are not perfectly carrier phase synchronized are also developed. These bounds will prove useful in determining the "best" system capacity, which can then be compared with the actual throughput achieved by a specific waveform.