Shadowing correlation assessment and modeling for satellite diversity in urban environments

Abstract

SUMMARYNon-geostationary orbit satellite networks have dynamic, yet deterministic topologies. This paper deals with the consequences of relying on the use of multiple visible satellites to improve availability with time/locations through satellite diversity techniques. The assumption of independent blockage events in two di!erent satellite-to-mobile links is generally not accurate and information on shadowing correlation should be taken into account in the assessment of availability. In this paper a shadowing correlation study for urban environments is presented and a model for the real environments, as well as for a generic urban environment is inferred. The model proposed here is simple and can be run on a computer. It also relates urban and constellation geometries thus allowing the identi"cation of those cases for which satellite diversity gain should be expected. As a result of this analysis and modelling, we present empirical analytical expressions describing positive correlation coe$cient as a function of satellite angular separation (azimuth and elevation). We also show that an angle exists above which correlation can be negative and satellite diversity can sensibly improve link availability.

An enhanced Markov chain based model for the narrowband LMS channel in built-up areas

“…In both instances, the resulting models reproduce the same satellite-to-mobile geometrical conditions. Additionally, building blockage correlation models have also been developed [6][7][8][9]. They address the needs of future LMS systems requiring several satellites illuminating the receiver's location to achieve the needed macro-diversity gain to overcome building blockage effects.…”

MIMO over Satellite: A Review

“…In [96] a methodology based on taking fisheye photographs at Loo -Loo potential user locations and extracting path-state information (clear/shadowed/blocked) from the images as a function of look angles was employed. Finally, an advantage of the SatD methodology presented in [101] and later adopted by [88] over measurement or fisheye campaigns is that it can be applied via a computer simulation based on simulating different realizations (azimuth scan series) of an ON/OFF random process, where the ON and OFF states correspond the existence of LOS or not.…”

Cognitive dual satellite systems

“…A number of works do focus on the signal/channel model for the LMS-DSS scenario [19,20,48,49]. A possible reason for this is that FSS-DSS system models presented in Section 12.3.2 could be directly applied to the LMS-DSS case.…”

“…This issue has been well studied, for example, in [19,20]. The interference in DSS can be classified in two categories.…”