Long range wideband channel measurements at 81–86 GHz frequency range

This paper presents a long range channel measurement system at 81-86 GHz frequency range along with initial channel characterization results. The measurement system enables channel measurements with link distances of several hundreds of meters. It utilizes a synthesizer sweeper and a frequency multiplier in the transmitter and the signal is measured in the receiver after a mixer with a vector network analyzer. As the long measurement distance requirement limits the usage of cables between the transmitter and receiver, only amplitude information is acquired from the channel. Instead, the phase information is acquired from the amplitude of the received signal using Hubert transformation. The channel measurements were performed in two different scenarios which were roof-to-street and street canyon measurement. The results reveal that 1) the measurement system operated well with link distances up to 685 m, 2) the repeatability of the measurement system is very good, and 3) according to the measurement results the line of sight component is dominant in the radio channel and the first multipath component at least 20 dB lower than the line of sight component.