Channel Estimation and Data Detection for Insufficient Cyclic Prefix SIMO-OFDM with Pilot Sub-carriers

In this work, we consider joint channel estimation and detection for orthogonal frequency-division multiplexing (OFDM) systems using insufficient cyclic prefix (CP) and pilot sub-carriers. A shorter CP can enable a significant reduction in bandwidth usage in OFDM systems. Alternatively, our methods can enable range extension for OFDM transmission with a certain CP length. The cost is increased inter-symbol interference (ISI) and inter-carrier interference (ICI), which corrupt the pilot sub-carriers. This can lead to a large channel estimation error. In this work, the effect of ICI and ISI on the received signal is analyzed. We then formulate a pilot sub-carrier based minimum mean square error (PSB-MMSE) scheme to estimate the time domain (TD) channel response for single input multiple output (SIMO) systems in the presence of ISI and ICI. From this, an iterative reception process of channel estimation and data detection is constructed. Simulation results show that the proposed scheme maintains satisfactory performance for channel delay spread more than twice the CP.