Combination of Kalman filter and constant modulus algorithm with variable stepsize for the equalisation of fast-fading channels

In fast-fading channels, the constant modulus algorithm (CMA) is unable to properly track the time-variations because the magnitude of the received signal changes too rapidly. The Kalman filter (KF), however, works well in time-varying channels but needs a training sequence to operate. Therefore, a combined CMA and KF algorithm is proposed in order to utilise the advantages of both algorithms. The associated step sizes of the CMA and the KF algorithm are also varied in accordance with the magnitude of the output. Simulations are presented to demonstrate the potential of the combination