Performance of multiband orthogonal frequency division multiplexing network in ultra wideband channels incorporating people shadowing and channel fading

Abstract

Ultra wideband (UWB) systems transmit signals across a much wider frequency than conventional systems and are usually very difficult to detect. UWB systems tend to be useful for short-range indoor applications. However, because of the short duration of UWB pulses, it is easier to engineer extremely high data rates. In multi-band orthogonal frequency division multiplexing (MB-OFDM) architecture, designers gain flexibility, reduction in power consumption, high spectrum efficiency and cost. In the earlier study, people shadowing has been considered to model attenuation in a packet-level UWB channel model. However, in dense short-range indoor applications, the effect of scatterers, diffractors and reflectors cannot be ignored. This happens mostly when the transmit antenna is omni-directional. Compared with the earlier work which incorporated only shadowing effects, this study discusses a packet-level UWB channel model subject to both multipath fading and people shadowing, which can arise even in an indoor channel (e.g. inside a hall of dimensions ∼ 10 m), and is incorporated in an MB-OFDM system. The performance analysis of the link is made based on link throughput and delay in servicing packets. The numerical results show the relative effects of various fading distributions, viz., Rayleigh, Rician, Weibull and Nakagami, together with people shadowing on the MB-OFDM system.