Precoding stacked space-time designs with quantized feedback

In this paper, we investigate limited feedback precoding for stacked space-time architectures over Rayleigh fading MIMO channels, for the cases where the components are taken from orthogonal or algebraic non-orthogonal designs. Stacked constructions allow to achieve high spectral efficiency. Our precoding approach enables an efficient decoding of the component codes and an improvement of the array gain. We use at the receiver a VBLAST signal processing which is based on a successive component interference suppression. For selecting the optimum precoding matrix among grassmannian codebook matrices, we consider a criterion based on maximizing the minimum signal to interference and noise ratio over all components of the stacked design. Simulations show that limited feedback precoding for a stacked algebraic design performs better than precoding for the cases of stacked Alamouti design and of spatial multiplexing scheme for the same number of transmit and receive antennas, the same spectral efficiency and the same number of bits on the feedback link.