A receiver architecture for maximum diversity transmissions over doubly-selective channels

In this paper, equalization of time-varying channels is discussed, where the channel is modeled by a complex exponential basis expansion model (CE-BEM). We consider a system where on the transmit side a precoder is employed to achieve maximum diversity. Along with an FFT decoder on the receive side, the resulting channel resembles an FIR filter on both matrix and scalar-level. We propose therefore a decision feedback equalizer (DFE), which bears a similar FIR structure as the channel. The equalizer taps can either be computed based on the channel knowledge, or adaptively estimated with the assistance of pilots. Simulations show that the proposed equalizer yields a satisfactory performance at a low hardware cost.