Direction Finding with Real-Valued ESPRIT for Noncircular Signal in Bistatic MIMO Radar

A novel real-valued ESPRIT (RV-ESPRIT) algorithm is proposed to estimate the direction of arrival and direction of departure of noncircular signal for bistatic MIMO radar. Based on the Euler’s formula, a new real-valued array vector of noncircular signal, whose elements is twice of the virtual array, is established with sine and cosine data. Then the receiving/transmitting rotational invariance factor is got through the receiving/transmitting selective matrix. Since its transmitting rotational invariance factor is cosine function, symmetrical mirror angle ambiguity may occur. Thus, a maximum likelihood function is used to avoid the estimation ambiguity. Since the proposed algorithm can double the length of virtual array elements, it can provide more precise angle estimation and detect more targets than some existing real-valued algorithms such as unitary ESPRIT. Simulation results confirm the effectiveness of the RV-ESPRIT algorithm.