Title :
Effect of Doppler spread in OFDM-based UWB systems
Author :
Capoglu, Ilker Rafet ; Li, Ye ; Swami, Ananthram
Author_Institution :
Sch. of Electr. & Comput. Eng., Georgia Inst. of Technol., Atlanta, GA, USA
Abstract :
Orthogonal frequency division multiplexing (OFDM) can be used in ultrawideband (UWB) communications to deal with delay spread of UWB channels. Relative motion between transmitter, receiver, and scattering environment induces Doppler spread. Since Doppler shift is proportional to subcarrier frequency, the time-selective fading is subcarrier dependent. In a narrowband (NB) system, this dependence is negligible, and all subcarriers are subjected to the same time-selective fading. However, in a UWB system, different subcarriers will experience different fading. In this paper, intercarrier interference (ICI) caused by the relative motion between transmitter and receiver in OFDM-based UWB communications is investigated. An exact expression as well as bounds is derived for the degradation of performance measured by signal-to-interference ratio (SIR). A design example is given to illustrate the concepts developed in the paper.
Keywords :
Doppler shift; OFDM modulation; fading channels; radio receivers; radio transmitters; radiofrequency interference; ultra wideband communication; Doppler shift; Doppler spread; OFDM-based UWB system; delay spread; intercarrier interference; narrowband system; orthogonal frequency division multiplexing; signal-to-interference ratio; time-selective fading channel; ultrawideband communication; underwater communication; Delay; Doppler shift; Fading; Interference; Narrowband; Niobium; OFDM; Scattering; Transmitters; Ultra wideband technology; Doppler spread; intercarrier interference (ICI); orthogonal frequency division multiplexing (OFDM); ultrawideband (UWB); underwater communications;
Journal_Title :
Wireless Communications, IEEE Transactions on
DOI :
10.1109/TWC.2005.853978
