Multipath propagation measurements on an overwater path in New Zealand

The results are described of a 140 Mb/s, 16 QAM digital microwave radio field trial to characterize multipath fading on a 60-km overwater route in New Zealand. Propagation data have been collected from the path between September 1985 and September 1986, and include one fading season of the Southern Hemisphere. The authors specifically apply and extend work on multipath fading by W.D. Rummler and others (1979, 1981, 1986). To the spectral data collected from the trial, a Rummler-type model (echo delay 6.35 ns) has been fitted. Distributions for the parameters a, b, and f_o ar observed to be similar to those presented by Rummler (1979) for the 26.4-mile Atlanta to Palmetto, Georgia path. Data which cannot be characterized well by the Rummler model include samples which show the evidence of a ray with equivalent long delay (⩾10 ns). This ray is either conjectured to be a sea reflection (however sea reflections are blocked at an Earth radius factor of k=4/3), or is indicative of the presence of more than one secondary ray