Frequency-domain equalization for multi-h CPM — An application to aeronautical telemetry

Frequency-domain equalization (FDE) is a low-complexity approach to remove the effects of intersymbol interference (ISI) introduced by propagation over a frequency-selective channel. In this paper, we present a novel receiver architecture for frequency-domain equalization of multi-h continuous phase modulation (CPM). The receiver front-end is a matched-filter bank, which is derived from a Laurent decomposition of the signal. A circulant-matrix model obtained for the samples of the matched filter is used to perform the equalization in frequency domain. It is shown that receiver complexity can be reduced by allowing a slight degradation in performance. The reduction in the complexity of the equalizer is proposed by dropping the FDE branches corresponding to low-energy Laurent pulses. It is observed that the loss in performance is acceptable even when a few significant branches are considered. Simulation results are presented for the IRIG-106 aeronautical telemetry dual-h CPM waveform.