A Wideband Frequency-Domain Channel-Sounding System and Delay-Spread Measurements at the License-Free 57- to 64-GHz Band

A channel-sounding impulse-response identification system using the swept-frequency method is presented for the 57- to 64-GHz band. The swept-frequency channel sounder offers high time and frequency resolution of 1 ns and 625 kHz, respectively. The high dynamic range (70 dB) and the constant power output enable the nonlinearities of the channel-sounding system to be overcome within the coverage range, which is on the order of a picocell. This paper also reports the measurements and the analysis of wideband propagation data for various indoor radio channels at the 57-to 64-GHz band. The propagation characteristics are assessed for six different propagation environments. The results of the measurements for four environments are compared when horn antennas are employed at both terminal stations, and also when a horn and an omnidirectional antenna are used at the Tx and Rx terminals, respectively. Examining the statistical distributions of the multipath dispersion, the 90th percentile is about the same for both antenna configurations. For all environments under investigation, it was observed that the static delay spread values at the 90th percentile were below 62 ns.