A new MAP-based channel estimation technique for multiple input multiple output diversity schemes

This paper presents a channel estimation technique amenable to space‐time coding (STC). An array of transmission antennas operates in band‐limited channels with intersymbol interference. The effectiveness of STC schemes requires the development of practical and high‐performance algorithms for channel estimation. The channel parameters, to be estimated at the reception antennas, are the attenuations and delays incurred by the signals transversal along the different propagation paths. The estimation technique is based on an iterative procedure derived through the maximum a posteriori probability (MAP) approach. Unlike classic estimation techniques, we iterate on the different probabilities of different coefficients rather than the coefficient values themselves. Two practical approaches are proposed, which are simplified versions of the general approach to implement the derived expressions required to estimate the actual channel coefficients. The performance of the two proposed algorithms has been assessed by simulation. Combined analysis/simulation results are presented and compared against those of conventional channel estimation techniques. Simulation results show that the required performance can be achieved with fewer number of iterations compared to conventional techniques. Copyright © 2006 AEIT