Experimental analysis of detection and localization of multiple emitters in multipath environments

An effective way for the joint detection and localization of multiple RF transmitters in a multipath environment is to enumerate the number of paths using the minimum-description-length information-theoretic algorithm, and to then measure the angle of arrival of each path, using an antenna array with a high-resolution direction-finding algorithm, such as MUSIC. The possible propagation paths are the angles corresponding to the peaks of the MUSIC pseudo-spectrum. Since more than one path may correspond to a single emitter source, further processing is required. The time-domain signals incident from these paths are then extracted with beamforming techniques, such as minimum variance, in order to estimate their coefficients of correlation with each other. These correlation coefficients are used to decide whether or not these paths correspond to the same emitter. Among the paths that appear to originate from the same source, the path with the time signal that contains the highest power is selected as the original path of the source. Hence, the number of emitters and their angles of arrival are jointly estimated. A performance analysis of the method is presented via real-time laboratory experimentation and discussed in this paper. To demonstrate the effectiveness of the proposed technique, experimental results with two uncorrelated sources were compared to experimental results with a single source and a reflector. All of the experiments were conducted in an anechoic test chamber.