Applications of Some Statistical Measures to Spatial Signal Processing

Author(s):  
Jean-Pierre Cadre
Author(s):  
V. M. Kutuzov ◽  
M. A. Ovchinnikov ◽  
E. A. Vinogradov

Introduction. In the case of a nonuniform (NU) design of the antenna elements (AEs) of the receiving antenna array (AA), the antenna pattern (AP) features sidelobes (SL) with a significantly higher noise level than acceptable values. Under low signal-to-noise ratios (SNR), this noise leads to angular coordinate measuring errors thus worsening the statistical accuracy characteristics (ACs) of the signal. It is of relevance to construct the ACs of angular coordinates when a modified parametric Burg method (BM) is applied to spatial reflected signal processing in a transportable decametre range radar (DRR) with a nonuniform array (NUA) and linear accuracy characteristics. Aim. To analyse the statistical ACs of angular coordinate objects when using a modified BM for spatial reflected signal processing in a DRR with a linear NUA, in which AEs are located with a random step in the range from λ/2 to several λ, where λ is the operating carrier wavelength.Materials and methods. Statistical ACs were constructed by computer modelling in the MatLab software, the reliability of which was confirmed by conventional discrete Fourier transform methods, as well as by comparing the obtained ACs with asymptotic bounds, including Cramer-Rao bounds.Results. The possibility and conditions of using a modified parametric BM for estimating the azimuthal coordinates of reflected radar signals were determined for the case of a nonuniform design of the over-the-horizon DRR receiving AA AEs. Statistical ACs were obtained and compared with the asymptotically optimal ACs of the maximum likelihood estimations corresponding to the uniform AE design.Conclusion. The obtained results confirm the suboptimality of the BM modified for signal processing in the NUA at a random AE spacing step in the range from λ/2 to 2λ, making it applicable for use in transportable DRRs.


2014 ◽  
Vol 513-517 ◽  
pp. 1600-1604
Author(s):  
Yuan Fei Xu ◽  
Li Hong Li

This paper proposes a joint spatio-frequency resource model and management strategy in cognitive MIMO (Multi-Input Multi-Output) systems by exploiting the spatial signal processing ability provided by multi-antenna techniques. With the scheme cognitive system could coexist with the primary in one occupied authorized frequency channel without interfere with the later. Accordingly cognitive transmission could be carried out even there is no idle spectrum available. This is a complement to traditional CR in which the performance of cognitive user depends to a great extent on the availability of spectrum hole. Simulation results show that compared with conventional CR, the proposed method could effectively improve the performance of cognitive user on the premises that no interference is imposed on the primary.


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