N-continuous orthogonal frequency division multiplexing (NC-OFDM) was demonstrated to provide significant sidelobe suppression for baseband OFDM signals. However, it will introduce severe interference to the transmit signals. Hence in this letter, we specifically design a class of low-interference NC-OFDM schemes for alleviating the introduced interference. Meanwhile, we also obtain an asymptot...

Concentric circular antenna array (CCAA) has interesting features over other array configurations. A uniform arrangement of elements is assumed where the interelement spacing is kept almost half of the wavelength and the array parameters such as the steering matrix and gain are determined. The array performance such as beam power pattern, sidelobe level and beamwidth are discussed in two cases ...

Applying a sparse constraint on the beam pattern has been suggested to suppress the sidelobe level of a minimum variance distortionless response (MVDR) beamformer. In this letter, we introduce a weighted sparse constraint in the beamformer design to provide a lower sidelobe level and deeper nulls for interference avoidance, as compared with a conventional MVDR beamformer. The proposed beamforme...

An ultrasonic transducer is a key component to achieve ultrasonic imaging. This paper designs a new type of Microelectromechanical Systems (MEMS) based capacitive ultrasonic transducer and a linear array based on the transducer. Through directivity analysis, it can be found that its directivity is weak due to the small size of the designed transducer, but the directivity of the designed linear ...

Dolph-Chebychev arrays are known to exhibit the best compromise between sidelobe level and directivity. However, they place a constraint on the null locations. Any attempt to impose nulls or get them deeper will impact the directivity/sidelobe level trade-off. In this work, null placement in Dolph-Chebychev arrays through element position perturbation is carried out based on Taguchi method whil...

It is well known that in the pulse compression radar theory, the sidelobe reduction using nonlinear frequency modulation (NLFM) signal processing represents a major and present research direction. Accordingly, the main objective of this paper is to propose an interesting approach related to the design of efficient NLFM waveforms namely, a temporal predistortioning method of LFM signals by suita...

This paper analyzes positive synergies and theoretical limits of the combination of acoustic echo cancellation (AEC) and Generalized Sidelobe Cancellers (GSC) for the removal of echoes of loudspeaker signals and local interferers. While the proposed system only requires one AEC for an arbitrary number of microphones, the array gain is limited by the number of sensor channels when all interferer...

The problem of designing Spread Spectrum radar detection filters that minimize sidelobe levels in both Doppler and range co-ordinates is considered and a new algorithm for the Doppler optimized mismatched filter is presented. The Iterative Reweighted Least Square procedure for minimax filter coefficients calculation is applied. A special attention has been paid to the analysis of Code Division ...

We mitigate the inter-channel-interference (ICI) in orthogonal frequency division multiplexing (OFDM) superchannel by adding cancellation sub-carriers (CCs). We experimentally show that CCOFDM outperforms conventional OFDM by 0.4-dB in a dual-polarization 400-Gbps 3360-km OFDM superchannel. Introduction Superchannels based on concatenating lowerrate orthogonal-frequency division multiplexing (O...