Narrowband interference detection in UWB systems

In February 2002, the FCC (2002 a, b) [1] issued a ruling that UWB could be used for data communications as well as radar and safety applications. UWB system is constrained to have a maximum power transmission of -41 dB and a bandwidth ranging from 3.1-10.6 GHz. UWB co-exists and does not interfere with existing narrowband or wideband communication systems in the same spectrum. However, due to low transmitting power, UWB is affected by the so-called narrowband interference. This paper presents a method to estimate and detect narrowband signals in radio impulse receiver with the intention of eliminating them. The method uses a power spectral density estimation technique called spectrogram to track down the narrowband signal. The spectrogram at specific frequency range of the active narrowband is larger than its overall average power. A threshold detector is built which reports detection at the frequency range where the narrowband is located The design correctness has been validated by means of Monte-Carlo simulation using UWB IEEE channel models, Time Hopping-Pulse Position Modulation technique and Rake receiver.