High-Resolution Angle-of-Arrival Measurements on Physically-Nonstationary Mobile Radio Channels

Abstract

A high-resolution measurement system for the characterization of the delay and angle-of-arrival properties of all significant multipath components on mobile radio channels is presented. The system uses complex impulse response data obtained from a novel 3-D tilted cross switched antenna array as input to an improved version of 3-D Unitary ESPRIT. Results from simulations and measurements show that the approach is capable of accurately characterizing the delay and angle-of-arrival characteristics of the dominant multipath components at moderate urban speeds along a trajectory in mobile propagation environments with high resolution in both azimuth and elevation.

Results of mobile channel sounding measurements in the 4.9 GHz public safety band

“…Conclusions A channel sounding system and a corresponding processing method have been presented for the characterization of mobile radio channels at 4.9 GHz. Advantages of the new equipment and processing method, compared to previous work presented in [4], are that they enable measurements of Doppler and polarization effects, and alleviate previous limitations on mobile receiver speed. Measured results obtained with the equipment described herein are expected to be of interest to users of the 4940-4990 MHz public safety band.…”

“…As is shown in the next section, availability of Doppler shift estimates enables phase differences measured between different antenna locations within the array to be corrected for motion of the mobile receiver and scattering objects. Thus, it is possible to obtain accurate direction-ofarrival (DOA) estimates using well-known array processing techniques, while alleviating limitations on mobile receiver velocity and/or array size that have previously had to be imposed [4]. The set of five data frames for each of the antenna ports in the array is referred to as a snapshot, and snapshots are acquired at a rate of 10 Hz.…”

Analysis of Scattering in Mobile Radio Channels Based on Clustered Multipath Estimates

“…3. Unreliable estimates were removed by using the reliability indicator presented in [6,10]. From the remaining dataset MPCs with very low power (\-100 dBm, in accordance with the simulations) are removed since they do not contribute significantly.…”

“…Measurements are performed using a recently developed 3-D high-resolution channel sounder [6], the receiver of which is shown in Fig. 1.…”

“…Recently, a 3-D highresolution channel sounder was developed based on a 3-D antenna array in combination with a multi-dimensional version of the Unitary ESPRIT algorithm [6,7]. The measurement system is capable of accurately measuring the angle-delay characteristics in both azimuth and elevation under mobile conditions.…”