Small-scale fading for high-altitude platform (HAP) propagation channels

Abstract

In recent years there has been a great interest in the development of high-altitude platforms, which are low cost stratospheric aircraft carrying payloads tailored for a wide range of applications in telecommunications and remote sensing. These platforms are capable of flying at altitudes ranging between 17 and 30 Km, with a potential endurance of weeks to months, features that make them attractive for the provision of future personal communication services. This paper deals with the theoretical derivation of a channel model for the communication link between the platform and terrestrial mobile users or stations. In particular, we address the problem of modeling the small-scale fading effects. It is shown that the particular geometry of the propagation scenario leads to a specific model applicable to the stratospheric channel.

On the Performance of Imt-2000 Communication Link Based on Stratospheric Platforms

“…al. [11] shows a good approach to the SPF channel. For DPSK modulation scheme under such fading channel condition, the closed form solution of bit error probability can be expressed by [18], is the average value of the signal to noise ratio, 2 β is unit variance of amplitude values of the fading channel, and K is the Rice factor.…”

“…The simplified model of propagation mechanism can be depicted such as in Figure 2. Specific research to the small scale propagation modeling for SPF channel is introduced in [11]. However the model doesn't analyze the impact of elevation and azimuth angle, in which the SPF is seen by the mobile station (MS).…”

Improving the system capacity of broadband services using multiple high-altitude platforms

“…To aid the subsequent analysis it is useful to define a set T of "test" users that are located at arbitrary points within the coverage area. It then follows that the set of elements that have CINR at or above a threshold from HAP can be expressed as (14) The sets can be matrix summed to give a new set which contains elements that record the number of platforms that can serve each arbitrary points at or above , i.e., (15) A new set of elements can be defined as the set of locations served by at least out of the set of HAPs (16) So the probability that at an arbitrary location within the coverage area that has a CINR at least dB and can be served by at least out of HAPs is (17) where the vertical bars mean the number of elements in the set.…”

“…To aid the eventual deployment of HAPs the ITU has recently allocated spectrum around 48 GHz worldwide [13] and 31/28 GHz for certain Asian countries [14], with spectrum in the 3G bands also allocated for use with HAPs [15]. There is now an emerging body of work on communications delivery from HAPs both for eventual 3G deployments, e.g., [16]- [20], as well as for communications deployed in the millimeter-wave bands. Spectrum sharing studies have been carried out e.g., [14], since all of these bands will be used by, or adjacent to, other services.…”

Space-Time Diversity Techniques for WCDMA High Altitude Platform Systems

“…However, owing to the amount of new infrastructures required, it will still be some time before 3G is ubiquitous, especially in developing countries. One possible cost effective solution for deployments in these areas is to use High Altitude Platforms (HAPs) (Collela et al, 2000;Djuknic et al, 1997;Grace et al, 2001;Miura & Oodo, 2002;Park et al, 2002;Steele, 1992;Thornton et al, 2001;) for delivering 3G (WCDMA) communications services over a wide coverage area (Dovis et al, 2002;Falletti & Sellone, 2005;Foo et al, 2000;Masumura & Nakagawa, 2002;Vazquez et al, 2002). HAPs are either airships or planes that will operate in the stratosphere, 17-22 km above the ground.…”