Adaptive multi-channel equalisation experiments with HF STANAG 4285 transmissions in interference

Adaptive multi-channel equalisation is investigated for HF STANAG 4285 transmissions by processing data collected during March-April 2000. The demodulation performance of a conventional multi-channel receiver is compared to that of a bespoke multiple, steered-beam one in interference scenarios in which a single-channel receiver either could not acquire, or had difficulty in acquiring, a signal. It is shown that the multiple-beam architecture can adapt using a short training sequence while maintaining excellent demodulation performance. Multi-channel processing for HF STANAG 4285 is shown to provide a reduction in the probability of bit error of two orders of magnitude or more over a single-channel COTS modem.