An improved technique for calculating outage time due to multipath fading effect

The authors present a unified analytical method for calculating the outage time of a digital radio relay system due to the multipath interference effect over line-of-sight paths. A computer program is used to simulate a two-path multipath transmission channel and the pulse-shaping networks in the modem. These simulations are used to obtain channel outage time caused by both multipath channel characteristics and design imperfections in the actual modem filters. Two illustrative examples are numerically performed on the DRAMA (Digital Radio and Multiplex Acquisition) system, which features both QPSK and QPR modulation schemes at carrier frequencies of 4 and 8 GHz. It is noted that this method of calculation can be easily extended to any multipath scenario consisting of three or more paths.<
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