Unraveling power spectra mixtures and finding the directions of the constituent sources can enable effective spatial occupancy prediction by location-dependent combining of the recovered source power ...spectra; and it is also useful for primary interference avoidance. Such unmixing and direction-finding is a challenging leap beyond ordinary `aggregate' spectrum sensing. This paper presents a promising new method for blind (power) spectra separation and emitter direction finding using a network of cognitive radios. Each radio has a pair of antennas, and the baselines of different radios are aligned (e.g., using a compass), in a configuration reminiscent of classical spatial correlation-based ESPRIT. Unlike classical ESPRIT, array geometry is exploited here in the temporal correlation domain to come up with a simple and effective blind spectra separation and direction finding solution with guaranteed identifiability and robustness to noise. A notable feature is that the different radios need not be synchronized, as they do in spatial ESPRIT.
