Pilot Sequence Design Scheme for MIMO OFDM Systems under Time-Varying Channels
Orthogonal frequency division multiplexing (OFDM) systems encounter performance degradations due to the time varying (TV) channels in wireless environments. As delay spread increases, symbol duration should also increase, and then OFDM systems become more susceptible to time-variations. Time-variations introduce inter-carrier interference (ICI), which must be mitigated to improve the performance in high delay and Doppler spread environments. In this paper, a pilot design scheme for multiple input multiple output (MIMO) OFDM system is proposed under TV channels. The properties of these pilots are described, and the simulation results are presented.