Local search based DOA estimation method in virtual co-prime array

Abstract

The invention discloses a local search based DOA (Direction Of Arrival) estimation method in a virtual co-prime array. The method requires that a transmitting signal is an intrinsic value signal. A receiving antenna array adopts a non-linear array. Through mirroring and space smoothing of the array, the virtual co-prime array is obtained. By applying a multiple signal classifying method on each sub-array of the array, a real angle and a corresponding fuzzy angle corresponding to each signal source can be obtained. According to the phase relation between the angles, an arbitrary angle can be obtained through local search on an angle domain and the other angles can be calculated directly, so that the complexity is reduced substantially. Finally, the real estimation value of angles can be obtained through combining estimation results of two sub-arrays of the virtual co-prime array.

Description

technical field [0001] The invention relates to the field of communication signal processing, in particular to a local search-based DOA estimation method using a virtual coprime array. Background technique [0002] The full name of DOA is Direction of Arrival, that is, the direction of arrival of the signal. The estimation of the direction of arrival is a problem often encountered in many engineering fields such as radar, sonar, wireless communication, etc. Using array antennas, DOA estimation can determine the current position of the signal source. At present, many methods have been developed in the traditional uniform linear array, such as multiple signal classification method (MUSIC), rotation invariant subspace method (ESPRIT), and minimum variance non-distortion method (MVDR), among which the MUSIC method is due to its estimated high The advantage of resolution has attracted people's attention. The disadvantage of the MUSIC method is its high complexity due to the globa...

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Problems solved by technology

[0002] The full name of DOA is Direction of Arrival, that is, the direction of arrival of the signal. The estimation of the direction of arrival is a problem often encountered in many engineering fields such as radar, sonar, wireless communication, etc. Using array antennas, DOA estimation can determine the current position of the signal source. At present, many methods have been developed in the traditional uniform linear array, such as multiple signal classification method (MUSIC), rotation invariant subspace method (ESPRIT), and minimum variance non-distortion method (MVDR), among which the MUSIC method is due to its estimated high The advantage of resolution has attracted people's attention. The disadvantage of the MUSIC method is its high complexity due to the global search of the spectrum. Therefore, it is difficult to apply the MUSIC method in occasions with high real-time requirements.

[0003] Traditional estimation methods focus on uniform linear arrays, but uniform linear arrays are not the optimal array structure. For example, in the presence of multi-frequency signal sources, if the array element spacing is designed with low-frequency signals, high-frequency signals will be blurred ; If the array element spacing is designed with high-frequency signals, the estimation performance of low-frequency signals will be reduced. Therefore, with higher requirements for estimation performance and implementation complexity, the nonlinear array architecture mode is adopted to fully exploit its spatial characteristics. Be the key to the field of DOA estimation

[0004] In recent years, DOA estimation based on nonlinear coprime arrays has gradually attracted the attention of the research community. Coprime arrays have the advantages of strong detection capabilities and high degrees of freedom. However, their shortcomings lie in the high complexity and The requirement of large aperture size limits the application of coprime arrays to a certain extent. In addition, more aspects need to be considered, such as fewer time samples, lower signal-to-noise ratio requirements, etc. For this reason, the present invention gives A DOA estimation method based on local search using virtual coprime array

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