A Low-Cost Platform for Time-Variant Wireless Channel Measurements With Application to Positioning

Channel modeling for the application of positioning requires the knowledge of multipath characteristics and the absolute delay information of the line-of-sight signal. Additionally, a smooth time evolution of the channel impulse response is essential for tracking algorithms used for this application. Hence, an accurate position information of transmitter and receiver antennas in a dynamic scenario is a requirement for channel sounder measurements. This paper describes a low-cost measurement platform which is able to cope with this requirement. Moreover, an extension of the parameter estimation space by constructing a virtual antenna array in the case of single-input and single-output measurements is possible. Therefore, the 1-D angle of arrival, propagation path amplitude, and delay can be estimated jointly. The proposed measurement platform is validated based on measured channel sounder data. From the extracted data, we present statistical results that are important for the application of positioning, which is the non-light-of-sight bias including its spatial correlation coefficient and the angle of arrival of the first detected path.