Reliability Analysis of Open-Loop Switching Loran Signal Generator Using Omoe Indicator

There are various parameters for conceptual design of a LORAN transmitter based on multi-level pulse width modulation (PWM), such as structural arrangement of amplifiers and number of modulation levels. The parameters should be considered in different aspects, such as implementation possibility, realization of LORAN signal standards and reliability analysis. In this paper, the overall measure of efectiveness (OMOE) indicator is used to simulate the reliability results of various open-loop LORAN transmitters based on multi-level PWM. So, by selecting the basic parameters and determining the weight of each parameter, the target value and the minimum acceptable value of each parameter, based on LORAN standards, are determined and OMOE is derived for several scenarios. The results of simulations show that the nine-level PWM arrangement is the most reliable structure. The OMOE of this structure is equal to 0.573, 0.506 and 0.451 (with average of 0.510) for the three states of all-safe amplifier blocks, and one- and two- damaged blocks, respectively. The average of this indicator for the same states are equal to 0.455, 0.463 and 0.485 for pulse amplitude modulation, and seven- and eleven-levels PWM structures, respectively, which have smaller values relative to the optimum structure.