An improved channel sounding technique applied to wideband mobile 900 MHz propagation measurements

Channel sounding experimental equipment to measure the wideband and variability characteristics of the 900 MHz mobile radio channel is presented. This equipment uses a modulated carrier, but no analog correlator. Various sources of nonlinearities may significantly degrade the dynamic range of estimated impulse response and, more seriously, introduce spurious signals undistinguishable from actual response components. The channel impulse responses are evaluated by a computerized postprocessing. A numerical technique for evaluating impulse responses, different from the classical correlation technique, is presented. Based on a regularized inversion and a windowing process, the signal processing algorithm is shown to produce responses with improved dynamics and resolution