GLRT-Based Combining Schemes for PPM IR-UWB Systems with Multiple Receive Antennas

This paper deals with impulse-radio ultra wide-band systems with multiple receive antennas. For binary PPM modulations, we propose various combining/detection schemes derived by the generalized likelihood ratio criterion. These schemes first combine delayed versions of the waveforms received at the different antennas and then compute the energies of the resulting signal over intervals smaller than half the symbol period. The decision statistic is finally obtained by a linear combination of these energies. The proposed algorithms can be implemented using currently available technology. They outperform a detection scheme that simply combines the decision statistics obtained (at each antenna) by means of a conventional energy-based detector. Their advantage increases with the number of antennas.