Analytical performance bounds are presented for trellis-coded MPSK, transmitted over a satellite-based land mobile channel. Upper bounds are evaluated using the well-known transfer function bounding technique, and lower bounds are achieved through knowledge of exact pairwise error probabilities. In order to analyze practical trellis-codes (four or more states), the uniform properties displayed by a certain class of trellis-codes are exploited, enabling the encoder transfer function to be obtained from a modified state transition diagram, having no more states than the encoder itself. Monte Carlo simulation results are presented in confirmation of all performance bounds and indicate a general weakness in the transfer function upper bounds. A new asymptotically tight upper bound is derived based on a simple modification to the standard transfer function bound, and results are presented for the four- and eight-state trellis-codes in Rician and Rayleigh fading.>

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/sub 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 (>or=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.>