Computation of Optimal Path Length for Terrestrial Line of Sight Microwave Link Using Newton–Raphson Algorithm

Abstract

This paper presents an efficient algorithm for determination of optimal path length of terrestrial line of sight microwave communication link. The algorithm computes and adjusts the path length based on the difference between the maximum fade depth the link can accommodate and the actual fade depth that is expected in the link. The algorithm uses Newton-Raphson iteration method to adjust the path length until it arrives at the optimal path length at which the maximum fade depth the link can accommodate and the actual fade depth that is expected in the link at the given set of link parameters. A numerical example is performed for a Ku-band microwave link at 12 GHz. The results show that after 4 cycle the algorithm converged when the path length dropped from its initial value of 19.9903km to the optimal value of 5.89Km. In addition, for free space, the initial value of 140.40dB drops to a value of 129.43dB at the optimal point and maximum fade depth dropped from initial value of 104.04dB to optimal value of 30.65dB.