Modified Successive Interference Cancellation for MIMO OFDM on Doubly Selective Channels

This paper proposes a new inter-carrier interference (ICI) cancelling scheme for multiple input multiple output (MIMO) orthogonal frequency division multiplexing (OFDM) in time and frequency selective fading channels. Based on the ICI distributions, we try to extend the conventional MIMO detection schemes. Nevertheless this extension increases the computational complexity significantly whereas the performance gain is not satisfactory. To improve the capability of ICI cancellation, we employ successive interference cancellation (SIC) method not in MIMO detection but in ICI cancellation. However, the processing delay time due to the SIC in OFDM will grow according to the increase of the number of subcarriers. To overcome this effect, we propose a modified SIC (MSIC) that can reduce the processing delay dramatically at the expense of some performance degradation. In simulation, we show the expense is so small that it can be ignored in severe time-selective channels.