Identification of time-variant directional mobile radio channels

For the real-time identification of the time-variant, directional structure of the mobile radio channel impulse response, a broadband vector channel sounder is described. The measurement procedure relies on periodic multi-frequency excitation signals, correlation processing and joint delay-azimuth superresolution based on the ESPRIT algorithm. The underlying signal model is developed and the different possibilities of ESPRIT application are discussed. Problems of imperfect receiver and antenna performance and the appearing resolution limits are outlined. Results of multidimensional correlation analysis of various channel scenarios in the Doppler-delay-angular domain are presented.