Wideband channel measurements and characterisation for broadband wireless access

This paper presents the results of propagation measurements at 3.5 GHz for a broadband fixed wireless access (BFWA) system with a directional subscriber antenna and a sectored base station antenna. First we describe the equipment and data processing methods used for extracting the channel impulse response. This is followed by the results of narrowband path loss measurements, and the statistics of the root mean squared (RMS) delay spread, with respect to subscriber unit (SU) antenna height. We show the influence of SU antenna height on a BWA system employing directional SU antennas and sectored base station antennas at 3.5 GHz. The path loss exponent at a SU antenna height of 10 m is close to 4, and between 2.2 and 2.7 for SU antenna heights between 7 m and 9 m. The wideband characteristics of the BWA channel, as quantified by the RMS delay spread show that 90 % of the channels have a delay spread of less than 100 ns. The average RMS delay spread is also observed to decrease with increasing SU antenna height. The maximum RMS delay spread observed in our measurements is less than 270 ns.