Performance of a layered space-time cellular system used with a fractionally-spaced channel estimator operated in a time-varying, frequency-selective wireless channel

A novel fractionally-spaced MIMO channel estimation scheme is presented for the layered space-time system that operates in a time-varying, frequency selective, fading channel. The new method estimates delay-spreads of several symbols, where the spacing of the echo arrivals is within fractions of a symbol period. The new method uses pilot symbols to estimate the channel characteristics. These are generated from a Paley-Hadamard pilot symbol matrix whose orthogonal and Toeplitz-like structure is able to resolve interference as well as minimise the length of the pilot sequence. Results of the performance of the fractionally-spaced MIMO channel estimator in a layered space-time system are presented for different channel scenarios.