A Fast Converging Blind Receiver for Space-Time Block Codes over Frequency Selective Channels

Space-time block coding (STBC) and a number of derivative techniques have been developed to maximise the diversity gain of a multiple-input multiple-output (MIMO) channel. For frequency selective fading - i.e. dispersive - MIMO channels, solutions in the literature are fewer, and are in their majority block based, such as MIMO OFDM or time-reversal STBC. In order to ultimately achieve better tracking behaviour, in this paper we focus on the development of a non-block-based method which utilises the constant modulus algorithm (CMA). Due to the slow convergence of the CMA, we propose the use of Newton´s method to find the optimum solution for the equalizer. A comparison of two different techniques of estimating the inverse of the correlation matrix is presented.