Improved RLS Based Adaptive Decision Directed MC-CDMA Receiver With Frequency Domain Interpolation for Rayleigh Fading Channels

In this paper an Improved RLS Based Adaptive MMSE Decision Directed MC-CDMA Receiver With Frequency Domain Interpolation (ImRLS-P) for Rayleigh Fading Channels is developed. The technique adopted by the ImRLS-P, is to reduce the noise components in the RLS-estimated channel frequency response before applying it to the MMSE adaptive detector and to reduce the computational rate as well. This is done by an IFFT, limiting window and an FFT. Simulation results in Rayleigh fading multiuser environments shows the ImRLS-P to outperforms the RLS in terms of BER and channel estimation average mean square error (AVMSE) with only an additional IFFT/FFT complexity increase. Furthermore, the ImRLS-P shows a comparable performance to that of the Pilot-Symbol-Aided approach for a mobile speed ¿ 60 km/h.