Propagation measurements using a digital channel sounder matched to the GSM-system bandwidth

Area coverage in the Pan-European Group Special Mobile (GSM) system requires both a specified minimum field strength and a high local probability that the length of the impulse response (IR) does not exceed a duration of about 16 mu s. Because of the lack of commercial equipment to measure and record complex IRs in mobile radio, an entirely digital channel sounder has been developed. Its bandwidth is matched to that of the GSM system. The minimum repetition time for the determination and storage of complex IRs is 23 ms. The maximum excess delay the hardware can cope with is 127 mu s. Details on calibration and examples of measured results are presented.<>