Differential Fade Depth with Path Length Adjustment (DFD-PLA) Method for Computing the Optimal Path Length of Terrestrial Fixed Point Line of Sight Microwave Link

Eke Godwin Kelechi, Constance Kalu, Akinloye Bolanle Eunice


In this paper, development of Differential Fade Depth with Path Length Adjustment (DFD-PLA) algorithm for calculating the optimal path length for fixed point terrestrial line of sight microwave communication link is presented.  The optimal path length for such link is defined as the path length at which the maximum fade depth is equal to the available fade margin the communication system can accommodate at the given set of link parameters. The DFD-PLA algorithm involved iterative adjustment of the path length based on the difference between the effective maximum fade depth and the available fade margin the system can accommodate. Sample 12GHz microwave link is analyzed and the results show that after 28 cycle the algorithm converged when path length, free space path loss and maximum  fade depth in the link dropped from their initial to optimal values of 19.9903 km to 5.8726 Km, 140.40 dB to 129.40 dB and 104.04 dB to 30.56 dB respectively.


Optimal Path Length; Microwave Link; Fade Margin; Fade Depth; Rain Fading; Multipath Fading; Differential Fade Depth

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