On the transceiver types of IR-UWB systems at sub-Nyquist sampling rates

In this paper, we present a unified performance analysis for different impulse radio (IR) ultra-wideband (UWB) transceiver types employing various modulation options and operating at sub-Nyquist sampling rates. Stored reference (SR), transmitted reference (TR), and energy detector (ED) receivers are considered employing one of the binary phase shift keying (BPSK), pulse position modulation (PPM), and on-off keying (OOK) modulation types. Realistic UWB channel models (the IEEE 802.15.4a channels) and practical pulse shapes (the root-raised cosine pulse) are used to characterize the statistics of the captured energies of different transceiver types at low sampling rates. The bit error rate (BER) expressions for different transceiver/modulation types are provided explicitly in additive white Gaussian noise channels. In multipath channels, the BER expressions are conditioned on the captured energies; then, the captured energy histograms at sub-Nyquist rates are used towards a semi-analytic evaluation of the BER for different transceiver/modulation combinations. The analyses are then verified via simulations using IEEE 802.15.4a channel models. The results show that in addition to their lower implementation complexities, the TR and ED receivers may be more favorable compared to SR receivers at low sampling rates in terms of their BER characteristics as well.