Tracking a MIMO Channel Singular Value Decomposition via Projection Approximation

A bidirectional multiple-input multiple-output (MIMO) time varying channel is considered. The projection approximation subspace tracking (PAST) algorithm is used on both terminals in order to track the singular value decomposition of the channel matrix. Simulations using an autoregressive channel model and also a sampled MIMO indoor channel are performed, and the expected capacity degradation due to the estimation error is evaluated.