Chips Equalization for Third Generation MIMO High Data-Rate Applications

Equalisers designed to restore the chip pulse shape [thus] are also effective in re-orthogonalising the transmit signals, and combining multipath components of the one transmit stream in order to reduce total mean squared error (MSE). Such structures have been described for single antenna configurations [5] [4] [3]. This paper extends the concept to multi-in-multi-out (MIMO) channels and furthermore utilises a correlator in the equaliser tap-update algorithm to reduce adaptation noise. Such a correlator was also proposed in [5] for the 1 x 1 case. Section II establishes a mathematical framework of the system, and derives the Minimum Mean Squared Error (MMSE) result, which sets a bound on the equalizer performance. The MIMO normalized least mean squares (NLMS) equaliser is derived in Section III. This is extended with a correlator in Section IV. Numerical comparisons are made in Section V.