Bringing High-Mobility to MISO-OFDM Systems based on FFT

Inhalt:
Orthogonal Frequency Division Multiplexing (OFDM) has become one of the key techniques in today’s wireless communications. Although recently wireless communications are developing very fast, the mobility of those systems often is limited. In time-variant channels moving transmitters and receivers create frequency shifts (Doppler effect) which destroy the orthogonality of the subcarriers. In this paper we propose a high-mobility feature: A Doppler compensation for multipleinput and single-output (MISO) OFDM systems which can be implemented with low complexity based on the fast Fourier transform (FFT). At the end, we compare different channel estimation algorithms and show that based on the orthogonal matching pursuit algorithm the channel can be estimated for the proposed Doppler compensation algorithm which can be implemented accurately based on the FFT.