Two dimensional equalization scheme of orthogonal coding multi-carrier CDMA under frequency selective fading environment

This paper describes a two dimensional (2D) equalization scheme using a higher degree equation to estimate the phase/amplitude variations of the frequency selective fading. The 2D equalization scheme reduces the multiple access interference (MAI) using the estimated parameters which is obtained by iterative estimation of the 2D coding preamble signal. The estimated phase variation of the frequency selective fading is obtained by a minimum square law using a higher degree predictive equation. The first degree and quadric equations are evaluated for frequency domain estimation. The estimated values are updated by a decision feedback equalizer (DFE). This paper evaluates the characteristics of the 2D equalization for the case of 2.048 Mbps of high speed data transmission under a frequency selective fading environment, when the fading frequencies are 50 and 100 Hz and two path conditions exist.