Channel pre- and post-equalization in uplink OFCDM systems with mobility

In this paper, we propose an up-link orthogonal frequency and code division multiplexing (OFCDM) mobile cellular system that uses channel pre-equalization at the mobile terminal (MT) and adaptive detection at the base station (BS). Assuming a time division duplex that may offer channel reciprocity between down- and up-links, a low-complexity channel pre-equalization avoids explicit channel estimation at the BS with a very good performance for low MT velocities. A data-aided adaptive detection at the BS starting directly in a tracking mode thanks to pre-equalization can compensate for the increasing mismatch between channel pre-equalization and actual channel response caused by large velocities all along the uplink frame. Simulation results using a 4G realistic scenario show that the proposed uplink OFCDM system offers a good performance with a high spectral efficiency, as it is able to transmit large data rates with mobility and no need of pilot symbols.