Outage capacity of pulsed-OFDM ultra wideband communications
Pulsed-OFDM is a novel modulation scheme proposed to enhance the baseline multi-band OFDM proposal for the IEEE 802.15.3a wireless personal area networks. Pulsating the OFDM symbols spreads the spectrum of the modulated signals in the frequency domain, leading to enhanced performance in multipath fading environments and reduced complexity and power consumption for transceivers. We study the information theoretic aspects of the pulsed-OFDM system. We provide formulas for average capacity and capacity versus outage probability characteristics in Rayleigh fading channels and use these formulas to determine the optimum spreading factor for the pulsed-OFDM system in a given channel condition. We also show that the optimum spreading factor is a function of the signal-to-noise ratio and capacity versus outage probability characteristics of the channel.