Performance of non coherent N-DPSK receivers with convolutional coding under additive white Gaussian noise and partial band noise jamming for a MDR frequency hopping system

Future EHF military satellite communication systems with on board processing (OBP) will have to provide a capacity in medium data rates (MDR) with a good protection against jamming to fulfil operational requirements. This protection can be achieved by the use of a frequency hopping system on a large bandwidth and the design of the on board receiver. For direct interoperability requirements with US MDR standard (188-136) the up-link modulation is limited to differential phase shift keying (DPSK). The studied N-DPSK non-coherent receivers have been described previously by Bataille, Testard and Levannier (see Proc. of IEEE Military Communications Conf., 1996). Its performance without coding has been evaluated analytically and simulated either under additive white Gaussian noise (AWGN) or partial band noise jamming (PBNJ) conditions. This receiver is based on the maximum likelihood criterion on N chips (or PSK symbols) and the L-diversity combining is achieved by weighting each repeated hop with a noise estimator. In this paper, we study the behavior of this new family of receivers with convolutional coding and a soft Viterbi decoder. We analyze the error statistics, the impact of interleaving and the length of the coder memory on the global performance. Our results has been obtained by simulations for several jamming conditions and for several window sizes N of the N-DPSK receiver to show the robustness of this waveform