  In ultra-wideband (UWB) communication systems with impulse radio (IR)
modulation, the bandwidth is usually 1GHz or more. To process the received
signal digitally, high sampling rate analog-digital-converters (ADC) are
required. Due to the high complexity and large power consumption, monobit ADC
is appropriate. The optimal monobit receiver has been derived. But it is not
efficient to combat intersymbol interference (ISI). Decision feedback
equalization (DFE) is an effect way dealing with ISI. In this paper, we
proposed a algorithm that combines Viterbi decoding and DFE together for
monobit receivers. In this way, we suppress the impact of ISI effectively, thus
improving the bit error rate (BER) performance. By state expansion, we achieve
better performance. The simulation results show that the algorithm has about
1dB SNR gain compared to separate demodulation and decoding method and 1dB loss
compared to the BER performance in the channel without ISI. Compare to the full
resolution detection in fading channel without ISI, it has 3dB SNR loss after
state expansion.
