Luebbers' and Maliuzhinets' solutions for diffraction by alossy wedge are compared in order to model the urban propagationchannel. Derivation, validity criteria and accuracy of impedanceboundary conditions (IBCs) --- as a main approximation embedded inthe Maliuzhinets' solution—are discussed. A modified (a slightlyimproved) Luebbers diffraction coefficient is proposed. The UniformTheory of Diffraction (UTD) Maliuzhinets diffraction coefficient isgiven in a structured form that might facilitate its use. Detailednumerical comparisons of the above-mentioned solutions with method-of-moments solutions using either exact boundary conditions or IBCsare done for canonical configurations.
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