Parameter Estimation Of Long Dipole/large Loop Under Model Mismatch

With the rapid development of the information age,the magnetoelectric signal has diversity,and the electromagnetic wave signal is more unpredictable in the time domain,frequency domain and polarization domain,leading to more research on the signal receiving problem.It is very important to determine the source position of incident electromagnetic wave,which is often used in aviation,navigation,direction finding,positioning and underwater detection.For electromagnetic wave,electromagnetic vector sensor is a kind of instrument with high sensitivity to measure its positioning Angle and polarization state.Polarization state is a unique attribute of electromagnetic wave,which is widely used in target recognition,radar location and other fields.Direction of Arrival（DOA）estimation is an important research content of Array Signal Processing（ASP）,and DOA estimation plays an important role in Signal source location.Estimation of Signal Parameters via Rotational Invariance Techniques（ESPRIT）algorithm and Multiple Signal Classification（MUSIC）algorithm.The space spectrum estimation algorithms represented by these two algorithms have become increasingly mature,and the parameter estimation algorithm of Electromagnetic Vector Sensors（EMVS）is developed on this basis.Because of its unique sensitivity to electromagnetic wave and its different structure of electric field and magnetic field information,the method of electromagnetic vector sensor is different from traditional array.ESPRIT requires the array to have rotation invariance,that is: Composed of two identical subarray,but electromagnetic vector sensor because of its unique physical structure composed of six components in a single sensor ensures the rotation invariant features,so the electromagnetic vector sensor array for its distribution in space is not too many restrictions,even by the single vector sensor measurement parameters could be carried out,Such advantages can work in many environments and improve the adaptability of its algorithm.Therefore,the following original work is done in this thesis:（1）The electromagnetic vector sensor is used to receive data,and when both the real model and the assumed model are short/long dipoles and small/large loop,the ESPRIT algorithm is used to estimate the spatial spectrum and rotation invariance respectively to estimate the elevation azimuth and polarization parameters.（2）the use of the electromagnetic vector sensor receives the data,and when the real model for long dipole/large loop（not ideal conditions）hypothesis model for short dipole/small loop（ideal conditions）,estimate the azimuth Angle and elevation Angle of polarization parameters,and gives the real value of calculating minimum mean square error（MSE）,and then derive the model mismatch of grams of Latin America under lower bound and evaluated.（3）The real model is derived as long dipole/large loop,and the assumed model is the Cramér-Rao lower bound of DOA parameters and polarization parameters in the mismatch model under the condition of short dipole/small loop.Real model for long dipole/large loop,the use of short dipole/small loop model to obtain the estimate and receive data using the real model into empty noise subspace,the first step to estimate as the initial value of iteration to find the minimum elevation Angle and polarization parameters,and then use the modified multiple signal classification algorithm is close to the real value.Finally,matlab simulation tool is used to simulate the proposed algorithm.In addition,short dipole/small loop algorithm,long dipole/large loop algorithm and optimized MUSIC are also simulated for comparison.MCRB is stable between short dipole/small loop algorithm and long dipole/large loop algorithm,providing reliable support for the algorithm under the mismatch model.The precision comparison shows that the proposed algorithm has obvious advantages in precision,support range and source number limitation.