Two-dimensional DOA estimation and channel phase disturbance correction method based on uniform circular array

Abstract

The invention relates to the field of direction-of-arrival positioning, and discloses a two-dimensional DOA estimation and channel phase disturbance correction method based on a uniform circular array. According to the two-dimensional DOA estimation and channel phase disturbance correction method, phase disturbance is processed at the cost of sacrificing the array aperture, and the method is a two-stage rank loss method. The two-dimensional DOA estimation and channel phase disturbance correction method comprises the steps of: 1, according to the characteristics of a Bessel function, truncatingan ideal steering vector in a compact uniform circular array mode space domain to construct a dimension reduction vector, and constructing a target function only related to phase disturbance based onthe dimension reduction vector and mode space domain conversion of channel phase disturbance; and 2, decoupling pitch and azimuth parameters in an ideal steering vector in a uniform circular array mode space domain to obtain a dimension reduction vector related to a pitch angle, and constructing a one-dimensional search target function only related to an azimuth angle. The two-dimensional DOA estimation and channel phase disturbance correction method provided by the invention can work online, and does not need an auxiliary array element. Besides, compared with a phase disturbance removing method based on a Hadamard product, the two-dimensional DOA estimation and channel phase disturbance correction method can be applied to a uniform circular array with a larger aperture, only needs a small number of array elements and can be applied to two-dimensional DOA estimation.

Description

technical field [0001] The invention belongs to the fields of piezoelectric array signal processing and damage location monitoring and estimation, and in particular relates to a two-dimensional DOA estimation and channel phase disturbance correction method based on a uniform circular array. Background technique [0002] In the field of structural health monitoring, since the structural damage source location technology is the premise and basis for the extraction of various damage signals and further feature analysis based on Beamformer technology, it has gradually become a research hotspot. Uniform circular array, as a common piezoelectric array structure, occupies an important position in this field because of its equal positioning resolution accuracy in 360° azimuth. In practical engineering applications, there are various errors in the steering vector of the array used, such as position error, phase disturbance, and array element mutual coupling, etc. These errors will re...

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Problems solved by technology

The correction source method is to estimate and correct the phase disturbance by setting a correction source with precisely known azimuth information in space. This type of method has good performance, but they cannot work online and require a correction source with precisely known azimuth information. often difficult to achieve in

The auxiliary array element method uses the accurately corrected array elements to construct the dimensionality reduction form of the array element domain steering vector, and uses the RARE theory and the subspace theory to search the space spectrum. This kind of method can work online, but it needs an accurately corrected auxiliary array. element, and the channel phase disturbance changes with time and environment, so that the phase disturbance must be re-measured and corrected every time before using the auxiliary array element, which often increases the complexity of engineering use

The advantage of the recently proposed Hadamard product-based method is that its DOA estimation performance is independent of the phase disturbance value, but this type of method can only deal with one-dimensional DOA, and the estimation degree of freedom is low, otherwise the incident signal must meet certain conditions, such as non-circular signal or non-Gaussian signal, etc.

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