Noncoherent Uwb Impulse Radio and Fm-dcsk: What Makes Them Different

For lack of empty radio bands, ultrawideband (UWB) radio system allowing reuse of already occupied frequency bands is the only solution to accommodate new wireless data communication services. Two types of UWB carriers are considered here, the frequency-shifted Gaussian pulse and chaotic signal with FM-DCSK modulation. A generalized model of transmitted reference systems is introduced first that makes the comparison of noncoherent UWB impulse radio and chaotic FM-DCSK system possible. The noise and interference rejection capability of a detector depends on the amount of a priori information exploited. In indoor radio applications the autocorrelation receiver is preferred since it provides the best robustness against the channel distortions. The paper shows that the autocorrelation receiver exploits only a limited part of a priori information, consequently, the noise performances of noncoherent UWB impulse radio and FM-DCSK are identical. Finally, the feasibility of noncoherent UWB impulse radio and chaotic FM-DCSK is verified. It is shown that UWB radios may be built by chaotic carriers and that UWB application offers a new research field for the chaotic research community.