Chip Discrimination for UWB Impulse Radio Networks in Multipath Channels

In this paper we present a technique that eliminates the need for centralized power control in ultrawideband (UWB) radio networks in multipath channel environments. The technique we call chip-discrimination, exploits the low duty cycle waveform of UWB impulse radio to mitigate the effects of high power interference using locally measured information at the receiver. Chip discrimination has been applied to UWB systems in non-multipath channels with matched filter reception. Here we develop a chip discrimination technique for multipath channels with RAKE receivers. A chip discriminator located at each RAKE finger selectively removes interfering pulses that exceed a dynamic threshold for each received multipath component. Computer simulation is used to demonstrate the effectiveness of the technique using the IEEE 802.15.3a channel model under the assumptions of both perfect and imperfect channel estimation using maximal ratio combining (MRC).