Yu. B. Nechaev, E.S. Makarov

Statistical performance analysis of high-resolution MUSIC-based DOA estimation in linear arrays is fulfilled. Analysis includes effects of amplitude-phase antenna uncertainties, mutual coupling effects and effects of multipath. Such analysis may be useful in development of ad-hoc wireless network with smart antennas. Root-mean square error dependencies on amplitude and phase errors are found through Monte-Carlo simulations. It is found that distribution of DOAs in the presence of amplitude errors is different from Gaussian and empirical formula for its description is proposed. Proposed formula agrees well with numerical simulations in the range of error magnitudes. Technical aspects of Pierre-Kaveh calibration method are carefully investigated and it is stated that global calculation of mutual coupling matrix doesn-t lead to perfect calibration. Two-step modification of their method is proposed to provide better estimates that assumes a priori knowledge of approximate direction to emitter. Such knowledge may be provided by initial DOA estimation without any calibration. Recommendations to application of Asztely model are carried out that include, particularly, minimal number of scattereres in model. Bounds for hardware calibration of digital beamforming array are defined through extensive computer simulation. Practically in the range of amplitude error about +/- 0,5 dB and range of angular spread no more than 4° magnitude of phase error may approach 10°. If the angular spread more than 4° it is difficult to approach good RMSE even with calibration.