Diffused Channel Estimation and Reception for Cyclic Prefix-free MC-CDMA Arrayed-MIMO Communication Systems

An arrayed-MIMO communication system, which employs antenna arrays at both ends of the wireless link, is proposed to leverage upon spatial information such as directions-of-arrival to achieve an improvement in performance. This is in contrast with conventional MIMO systems, which typically assume multiple independent antenna elements at the transmitters and receivers. This paper focuses on an arrayed-MIMO communication system operating over a frequency selective fading channel and employs MC-CDMA as the modulation technique. However, in a departure from conventional MC-CDMA systems, cyclic pre xes or guard intervals are not used for the MCCDMA system employed here so that valuable bandwidth is not wasted on cyclic pre xes or guard intervals. Localized scattering is assumed to occur for each multipath; hence the wireless channel is modelled as a diffused vector channel. A robust blind estimation method is presented to estimate the parameters of the spatially diffused channel, followed by reception based on these parameters. The feasibility of the proposed system is supported by simulation results. Index Terms Antenna arrays, MC-CDMA, channel estimation, multipath channels, spatial diffusion, angular spread.