Intersymbol Interference Cancellation Based on Wavelet Transformation for Indoor Ultrawideband Positioning Systems

For
ultrawideband
(UWB) positioning using impulse radio,
intersymbol interference
(ISI) is unavoidable, which affects the positioning accuracy. In this paper, a novel ISI cancellation scheme based on wavelet transformation for indoor UWB positioning is proposed. Knowledge of the channel is not required. The desired signal pulse can be distinguished from the interference pulse and precisely located. Instead of using the traditional received pulse, wavelet transformation is applied to generate a new spike signal for detection. A detailed theoretical analysis is presented and closed-form expressions are derived. The proposed scheme is applicable to any types of UWB pulse waveforms and robust in the case of multiple interference pulses. Both simulation and experimental results show that the UWB positioning system with the proposed ISI cancellation scheme can achieve significantly higher positioning accuracy than the original positioning system without ISI cancellation.