Estimation of Doubly Selective MIMO Channels Using Superimposed Training and Turbo Equalization

We propose superimposed training in conjunction with space time turbo equalization for communication over multiple-input-multiple-output (MIMO) wireless links in doubly selective environments. The iterations of the turbo algorithm provide the flexibility to reincorporate data energy along with the pilot energy into channel estimation so that simultaneous data transmission actually aids in channel estimation rather than interfering with it. We demonstrate the iterative method has the ability to improve the BER performance significantly over a comparable non iterative scheme.