Iterative Interference Reduction in Single Carrier Block Transmission without Cyclic Prefix

Single carrier systems with frequency domain equalization (FDE) have attracted much attention for their efficient implementation of equalization and superiority over multi-carrier schemes from the practical point of view. In this paper, we consider a single carrier system in which for achieving higher spectral efficiency the cyclic prefix is not transmitted at the beginning of blocks. This poses a major inter block interference at the receiver which we suppress by a method known as overlap FDE. However, even by using this method we still deal with a significant amount of residual interference from the previous block. In this paper, we suggest using an iterative structure, known as iterative block frequency domain equalizer (IBDFE), to reduce the residual interference. We also utilize a Gaussian approximation approach to model the residual interference and modify the filter design in IBDFE accordingly. We show that with this modification we are able to reduce the residual interference very efficiently such that for a major part of the block the overall interference is comparable with that of a CP-assisted single carrier system.