Adaptive Propagation Prediction using Lee’s Model in a Non-Homogeneous Environment
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The need to improve the accuracy of signal propagation prediction in an environment of variable building/clutter density drove the development of a tool that would facilitate the compilation and analysis offield collected signal strength measurements to improve results offuture radio coverage analyses. The output of the analysis produces a set of signal attenuation parameters that are representative of the environment tested. The Lee Area-to-Area Path Loss Prediction model was chosen as the methodology with which the measured field parameters were applied. These derived parameters were the 1-mile intercept point and path-loss slope particular to Lee’s model. The approach for deriving these parameters is based on measuring an unmodulated carrier and correlating the measurement sample with a GPS derived location. The collection of measurements was grouped by the environment classification, for example, dense urban, urban, suburban, etc. Therefore, each of these environments are represented by a new set of Lee parameters. The adaptive or automatic assignment of these parameters is facilitated with the use of a spatial land-use database which contains information about the environment classification areas. This database enables the propagation characteristics of the environment to be automatically changed as a radio unit traverses from area to area. In the case where the propagated signal crosses environment boundaries, special care is taken to adjust the rate of signal attenuation using Lee’s paradigm.
KeywordsPropagation Path Path Loss Environment Type Antenna Height Propagation Prediction Model
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