Ultrawide bandwidth signals as shot noise: a unifying approach

Abstract

Abstract-We present a shot noise based model for a large family of ultrawide bandwidth (UWB) signals. These include time-hopping and direct-sequence signaling with pulse position, interval, and amplitude modulations. Each specific signal is constructed by adding features to a basic model in a modular, simple, and tractable way. Our work unifies the contributions scattered in the literature and provides a general approach that allows various extensions of previous works as well as new results. The exact power spectrum is then evaluated using shot noise spectral theory, which provides a simpler, systematic, and rigorous approach to the spectra evaluation of complicated UWB signals. The strength of our methodology is that different features of the signal model contribute clearly and separately to the resulting spectral expressions.Index Terms-Point processes, power spectrum, pulse modulated signals, shot noise, ultrawide bandwidth.

Frequency Offset Estimation for MB-OFDM-based UWB Systems

“…(1,5,6,7) Cor. (1,5,6,7,11) compensation are performed independently in each band and there is no averaging across the three bands.…”

“…, H q,p } and 1 denotes the all-one column vector, whose size should be apparent from the expression. Next, we combine the CFO estimates { υ q,p } obtained from the different preamble parts in the various frequency bands by using the BLUE principle, together with (6) and (16) (20) where the weighting values are given bȳ…”

“…If the abrupt channel change results in an increase of the received snap-shot SNR from below to above the SNR threshold of the sync detection (from bad to good SNR), the preamble part before the abrupt channel change would not be detected and hence, is not used in the OFO estimation. In addition, if the number of preamble symbols with good SNR in each band is less than a certain value ζ (we use ζ = 3 for the pattern 1 (or 2) and ζ = 4 for the pattern 3 (or 4) in our simulation), neither the OFO estimation nor data detection would be reliable 6 . Hence, we skip the OFO estimation (and 6 Recall that the operating SNR of UWB systems is low.…”

“…In addition, if the number of preamble symbols with good SNR in each band is less than a certain value ζ (we use ζ = 3 for the pattern 1 (or 2) and ζ = 4 for the pattern 3 (or 4) in our simulation), neither the OFO estimation nor data detection would be reliable 6 . Hence, we skip the OFO estimation (and 6 Recall that the operating SNR of UWB systems is low. If the abrupt channel change results in a drop of the received snap-shot SNR below the SNR threshold, the receiver would not be able to detect the remaining data correctly.…”

“…Due to ultra-wide bandwidth, UWB systems can operate at low power spectral density which allows overlay with other narrow-band systems. The coexistence issue and the spectral analysis of UWB systems have been investigated in [4]- [6]. Another approach to realize UWB systems is multi-band orthogonal frequency division multiplexing (MB-OFDM) [7] which has been proposed for the IEEE 802.15.3a standard [8] and adopted in European Computer Manufacturers Association (ECMA) standard [9].…”