Combining space frequency coding with a pre-filtering technique for TDD downlink MC-CDMA systems in a beyond 3G context

Abstract

This paper deals with downlink space-frequency block coding with a joint pre-filtering and spreading technique for time division duplex MC-CDMA. We consider the use of antenna arrays at the base station (BS) and a single antenna at the mobile terminal (MT). The space-frequency block codes allow that the spatial diversity be efficiently exploited and the linear multi-user pre-filtering technique allows to format the transmitted signals so that the multiple access interference and channel distortions at mobile terminals are completely removed, keeping the MT at low complexity. Simulations results are carried out in scenarios with both perfect and imperfect channel estimates and using the channel turbo code specified for current UMTS system, to demonstrate the effectiveness of the proposed SFBC with a linear multi-user pre-filtering approach.