In a generalized sidelobe canceler using normalized least mean square adaptation, interference coming in on sidelobes can be mitigated when using a small adaptation stepsize. In that case, any interference arriving from the main beam look direction will be viewed as a desirable signal, and therefore passed on. Previous studies have identified narrowband interference scenarios where interference...

We demonstrate a new focus engineering scheme to achieve both extended depth of focus (DOF) and sidelobe suppression in spectral-domain optical coherence tomography (SD-OCT) system. Each of the illumination pupil function and the detection pupil function is modulated using an annular pupil filter implemented by center obscuration. The two pupil filters are arranged in a dark-field configuration...

The use of a generalized sidelobe canceler (GSC) can significantly improve the lateral resolution of medical ultrasound systems, but the contrast improvement isn't satisfactory. Thus a new Eigenspace-based generalized sidelobe canceler (EBGSC) approach is proposed for medical ultrasound imaging, which can improve both the lateral resolution and contrast of the system. The weight vector of the E...

—In this paper, the goal is to achieve an ultra low sidelobe level (SLL) and sideband levels (SBL) of a time modulated linear antenna array. The approach followed here is not to give fixed level of excitation to the elements of an array, but to change it dynamically with time. The excitation levels of the different array elements over time are varied to get the low sidelobe and sideband levels....

The conventional polyphase pulse compression codes including Frank code, P1, P2, P3, and P4 code suffer severe signal loss in performance under Doppler environment. This paper proposed a new polyphase pulse compression codes which are conceptually derived from the step approximation of the phase curve of the hyperbolic frequency modulated chirp signal. Comparing with the above conventional code...

This paper presents the development and performance evaluation of a methodology for distinguishing between mainlobe and sidelobe detections that arise in adaptive radar systems operating in adverse environments. Various adaptive detection test statistics such as the adaptive matched filter (AMF), the generalized likelihood ratio test (GLRT) and adaptive coherence estimate (ACE), and combination...

We introduce a new hybrid algorithm called the generalized sidelobe decorrelator (GSD) that combines elements of geometric beamforming and blind source separation. On the one hand, it is an extension of the generalized sidelobe canceller (GSC), also known as the Griffiths-Jim beamformer, from the standard criteria of power minimization to a decorrelation criteria. On the other hand, it can be s...

In this paper a pipelined realization of a Transform Domain adaptive beamformer, is presented. The sliding Discrete Fourier Transform is utilized for the data transformation. The adaptation process is performed by the Delayed Least Mean Squared, Gereralize Sidelobe Canceller. By proper retiming of the introduced delays, fully pipelined architectures are derived, suitable for parallel implementa...