Investigation of VHF signals in bands I and II in southern India and model comparisons

Abstract

In order to achieve a highly reliable communication with a simple and small receiver, one requires the knowledge of the spatial and temporal variability of field strength. This assumes greater significance in broadcasting applications where the user expects a very high quality signal. The performance of any communication circuit depends on the models employed to calculate the coverage area and interference problems. The development and identification of models is a continuing and ongoing process and there is always scope for refinement. With this objective some field strength measurements were conducted using Chennai TV and FM stations in several radials. The variability of the path loss as a function of distance has been studied and path loss exponents deduced from the observed values were compared with the model available in literature. The agreement and deviations of the model with the observed results are presented and discussed and two approaches have been proposed to compare the observed results.