Characterization system for radio channel of adaptive array antennas

This paper describes a multichannel measurement system for the analysis of the radio channel of adaptive array antennas. It provides real-time recording of signals from multiple input channels. Due to this multielement reception, the incidence angles of the received signal components can be resolved. Wideband sounding provides the delay information. This allows the characterization of the two-dimensional radio channel of adaptive antenna systems in realistic environments. The system is based on a complex wideband radio channel sounder and a fast RF switch. As an example, the system allows measurement of complex impulse responses for a 16-element array with 17 ns delay resolution, and a delay range of 4.3 μs for a 26 m/s mobile speed. The continuously recorded path lengths can be over one hundred meters. Practical channel measurements have been performed with a linear array of 8 elements. In these measurements the received signal components could be separated with 13° angular and 20 ns delay resolution. The developed method provides a novel approach to the two-dimensional analysis of the mobile environment