Power Delay Profile estimation for MIMO-OFDM systems over time-varying multipath channels

This paper investigates the problem of estimating the Power Delay Profile (PDP) for Multi-Input Multi-Output Orthogonal Frequency Division Multiplexing (MIMO-OFDM) systems over fast time-varying multipath channels. By using the information of both the Cyclic Prefix (CP) segment and partial received samples, we propose a blind Maximum-Likelihood (ML) PDP estimation algorithm without any assistance of pilots. Furthermore, to reduce the computational complexity, the exact solution of ML estimation is simplified to a series of two-dimensional searches by the alternating-projection method. Finally, the performance of our algorithm is verified by extensive simulations.