Location Variability of the Field Strength Local Median Values in the Medium Wave Band

The digital broadcasting systems (DRM and HD radio/ IBOC) developed in the last decade have renewed the interest for the MW band. The planning requirements of the digital services require more accurate channel models and a significant improvement in the coverage estimation algorithms. The variability of the local median values (sigmaL) is a key parameter in the estimation process of the coverage percentage within a certain service area. Similar studies are scarce in the bibliography, mainly because analogue service planning requirements have been much more flexible. This paper presents the first set of sigmaL values for the MW band, and analyzes the influence of several factors related to the channel model and the coverage estimation techniques, such as frequency, distance to the transmitter, path profile and relevant features of the reception area.