ON COMBATING DEEP FADES DUE TO GROUND REFLECTION IN POINT-TO-POINT WiMAX COMMUNICATIONS

In point-to-point wireless communications, the re- ceived signal may experience deep fading due to different propa- gation phenomena. In this paper, we deal specifically with ground reflection and show how it affects the system communication. As application, we consider the example of point-to-point WiMAX communications between base stations (BSs) and trains. The fading problem is mainly due to the fact that both direct and reflected rays are located in the main lobe of the base station antenna and then the correspondant fields have almost the same amplitude. In this paper, we propose several efficient solutions in order to overcome the fading problem. These solutions perform different techniques based, first, on modifying the shape of the main lobe of the BS antenna in order to decrease the magnitude of the ground reflected field, and second, on modifying the antennas polarization. In order to support our propositions, a large set of simulation results is reported and discussed. (C) 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:1641-1645, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26063