Inter-cell Interference Analysis on Multi-Carrier CDMA System

Abstract

In this paper the downlink inter-cell interference (ICI) of the multi-carrier CDMA systems is analyzed. Based on the concept that is always employed in the WCDMA multi-cell link-level simulation, radio geometry concept, we build a multicell MC-CDMA link-level simulation model with acceptable computing complexity and reliability. The question whether ICI can be modeled by additive white Gaussian noise (AWGN), i.e. Gaussian Approximation (GA), which is always assumed for most of the simulations, is addressed. In different scenarios, with different number of users in surrounding interfering cells and synchronization offset, the interference is analyzed by simulation on the model. The results turn out that the interference in the MC-CDMA system is not always perfectly white. It depends on some factors in the system. Furthermore, the difference between real ICI and GA is also presented.

Application of Fractional-Order PI^λ Controller for PMSM Speed Control

“…Therefore, we have the following conclusion based on graphical stability criterion: The critical roots are in the right-half plane in the parameter space to the left of the curve (k p (ω),k i (ω)) when we follow this curve in the direction od increasing ω, whenever det(J)<0 and to the right when det(J)>0. Solving equation (7) for k p and k i in terms of λ and ω yields…”

“…Fractional-order controller and its system attaches highly importance in control field. Especially in analysis and design, we have gotten some achievements [1][2][3][4][5][6][7]. The control properties and parameters tuning of PI λ D µ controller were investigated by using the mapping root locus in [1].…”

“…A modified differential evolution algorithm with parameter self-adjusting was presented to tune the controller in [6]. Considering fractional controller from the sight of system zeros or poles, using fractional-order extended frequency domain analysis method, the authors provided a simply reasonable type of fractional-order PI λ D µ controller and a kind of separable fractional lead-lag compensator in [7]. In addition, the fractional-order controller and its application also gets certain results [8][9][10][11].…”