Band-limited frequency efficient orthogonal pulse shape modulation for UWB communications

This paper addresses the design of an equally frequency limited set of orthogonal pulses adequate for an impulse radio (IR) ultra wideband (UWB) communication system employing M-ary pulse shape modulation (PSM). UWB systems have to face many spectrum restrictions due to potential interference to sensitive existing systems, comply with maximum bandwidth regulations or fit into spectrum masks like the one emitted by the Federal Communications Commission (FCC). Then, UWB systems have to restrict their bandwidth and maximize its usage efficiency. Additionally, future narrowband communication systems can be allocated in portions of the spectrum where UWB systems operate, and they may not tolerate possible interference from UWB emissions, this would lead to the mandatory use of a stop-band filter in the UWB transmitters. The proposed set of orthogonal pulse-shapes provides both pulses equally limited in frequency and robustness against such a narrowband interference canceller filter.