In this paper, the problem of estimation

of fast time-varying radio channels is considered. A

new algorithm, Iterative Channel Estimation is

presented. This algorithm is designed for radio

channel estimation in multiple-input multipleoutput

systems with space-time block coding. The

channel transfer matrix is estimated on the basis of

a previously decoded data, so it can be performed

simultaneously with the data transmission. The

estimation process is a simple operation, just a

multiplication of two matrices. As a result, bit error

rate is reduced. The algorithm is compared to the

differential space-time block codes and verified by

Monte-Carlo simulations.