The performance or PRS-OFDM in multiple antenna system

Abstract

The main advantage of OFDM transmission comes from the fact that the Fourier basis forms an eigenbasis for time invariant channels [1]. This allows simplification on hardware implementations especially at the receiver. For example, when the channel is time-invariant within one OFDM transmission block, the equalizer is just a single-tap filter in the frequency domain. Combined with multiple-input multiple-output channels (MIMO), MIMO-OFDM has a potential of achieving high data rates. However, the block time-invariance assumption may not be valid at high mobile speeds where impairments such as frequency offset are likely to occur. Such scenario resulted to loss of orthogonality of the OFDM subcarriers that leads to inter-carrier interference (ICI) in addition to signal rotation and attenuation. With the increasing frequency offset occurrence, the degradation of BER performance in OFDM system enhances further [1].