Variable forgetting factor PASTd algorithm for time-varying subspace estimation

A new subspace tracking algorithm based on the PASTd algorithm is proposed. The algorithm is obtained by introducing the variable forgetting factor, which adapts itself to the time-varying subspace environments. The tracking capability of the proposed algorithm is demonstrated by computer simulations in an abruptly changing DOA scenario. The estimation results of the variable forgetting factor PASTd (VFF-PASTd) algorithm outperform those of the PASTd algorithm in the nonstationary case as well as in the stationary case