Linear precoding for layered space-time block coding with correlation feedback

We propose a linear precoder for the layered space-time block coding system [2] over spatially correlated channels with channel covariance matrix feedback at the transmitter. The precoder is a combination of the well known waterfilling solution and the precoder for spatial multiplexing system that minimizes the probability of decoding error. At the receiver, decoding schemes of group zero-forcing and group minimum mean squared error with successive interference cancellation are utilized to decode the transmitted signals. Simulation results demonstrate the superiority of the combined linear precoder over the pure waterfilling solution or the spatial multiplexing precoder in correlated channel. This conclusion confirms the intuition that the optimal linear precoding should be robust to both the space-time block coding and spatial multiplexing systems.