On Implementing Spatial-Correlation-Information Aided Feedback in Practical MIMO Systems

This work investigates implementing spatial-correlation-information aided feedback in practical multiple-input multiple-output (MIMO) systems. It is presented that the existing spatial-correlation-information aided feedback approach could be simplified in computational complexity with little performance loss. In comparison with Grassmannian codebooks, the feedback codebooks in the 3GPP LTE Release-8 specification is shown to be a near-optimal base codebook. An efficient quantization approach is proposed for quantizing transmit spatial covariances matrices for closely-spaced co-polarized uniform linear arrays (ULA). The good performance of the entire practical feedback solution is demonstrated via system-level simulation.