Abstract In this paper we focus our studies on LTE, which is a development under 3G technologies Release-8 of the 3GPP Project plan and is considered a baseline and step towards the LTE-Advanced. In orthogonal frequency division multiplexing networks, inter-cell interference results in poor performance, especially universal frequency reuse scheme has already been used. Soft Frequency Reuse (SFR) scheme, one of the most promising... In this paper we focus our studies on LTE, which is a development under 3G technologies Release-8 of the 3GPP Project plan and is considered a baseline and step towards the LTE-Advanced. In orthogonal frequency division multiplexing networks, inter-cell interference results in poor performance, especially universal frequency reuse scheme has already been used. Soft Frequency Reuse (SFR) scheme, one of the most promising inter-cell interference coordination (ICIC) schemes, has been introduced in LTE-Advanced networks. In this paper, we develop an analytical queuing model for the SFR scheme taking into account the features of SFR scheme and its impact on system performance firstly. Then, we improve the iterative algorithm called successive over-relaxation (SOR) to solve the set of linear equations and get the steady state probability distribution. Finally, performance analysis shows that maximum number of resource that cell-edge users can use and the number of cell-edge users correlate with the performance of SFR scheme. Read More Read Less

Abstract Economic load dispatch is performed by the utilities in order to determine the best generation level at the most feasible operating cost. In order to guarantee satisfying energy delivery to the consumer, a precise calculation of generation level is required. In order to achieve accurate and practical solution, several considerations such as prohibited operating zones, valve-point effect and ramp-rate limit need to be... Economic load dispatch is performed by the utilities in order to determine the best generation level at the most feasible operating cost. In order to guarantee satisfying energy delivery to the consumer, a precise calculation of generation level is required. In order to achieve accurate and practical solution, several considerations such as prohibited operating zones, valve-point effect and ramp-rate limit need to be taken into account. However, these considerations cause the optimization to become complex and difficult to solve. This research focuses on the valve-point effect that causes ripple in the fuel-cost curve. This paper also proposes Differential Evolution Immunized Ant Colony Optimization (DEIANT) in solving economic load dispatch problem with valve-point effect. Comparative studies involving DEIANT, EP and ACO are conducted on IEEE 30-Bus RTS for performance assessments. Results indicate that DEIANT is superior to the other compared methods in terms of calculating lower operating cost and power loss. Read More Read Less