MULTI-SYMBOL NONCOHERENT DETECTION OF MULTI-H CPM

Abstract

Two receivers are presented for the general case of noncoherent detection of multi-h continuous phase modulation (CPM). Both receivers yield performance gains using multi-symbol observations. The first is an existing receiver [1, 2] which has previously been applied to PCM/FM [3] and is now applied to the ARTM Tier II telemetry waveform. The second receiver is presented for the first time in this paper. The existing noncoherent receiver is found to perform poorly (and with high complexity) for the ARTM Tier II case. For single-symbol observations, the new receiver outperforms conventional FMdemodulation for both telemetry waveforms, and for multi-symbol observation lengths its performance approaches that of the optimal coherent receiver. The performance is evaluated using computer simulations. Receiver performance is also evaluated using a simple channel model with varying carrier phase. The traditional FM demodulator approach is found to outperform both receivers as channel conditions worsen.