The cognitive radio wireless sensor network (CR-WSN) has gained worldwide attention in recent years for its potential applications. Reliable spectrum sensing is the premise for opportunistic access to sensor nodes. However, as a result of the radio frequency (RF) front-end nonlinearity of sensor nodes, distortion products can easily degrade the spectrum sensing performance by causing false alar...

A sample-and-hold amplifier designed for the front end of high-speed low-power analog-to-digital converters employs a BiCMOS sampling switch and a low-voltage amplifier to achieve a sampling rate of 200 MHz while allowing input/output voltage swings of 1.5 V with a 3-V supply. The circuit also incorporates a cancellation technique to relax the trade-off between the holdmode feedthrough and the ...

Testing for a unit root in a series obtained by summing a stationary MA(1) process with a parameter close to -1 leads to serious size distortions under the null, on account of the near cancellation of the unit root by the MA component in the driving stationary series. The situation is analysed from the point of view of bootstrap testing, and an exact quantitative account is given of the error i...

The time-varying dispersion of ultrafast laser pulses can be self-adaptively stabilized using real-time dynamic spectral holography in semiconductor photorefractive quantum wells. Dispersion of all orders is compensated by forming a dynamic spectral-domain hologram of a signal pulse ~that has a time-varying dispersion! referenced to a stable clock pulse. The hologram is read out using forward-s...

Cyrille SICLET and Pierre SIOHAN France Télécom R&D (DMR); 4, rue du Clos Courtel; BP59; 35512 Cesson Sévigné; France Tel: +(33)299 12 38 35; Fax: +(33)299 12 40 98; E-mail: [email protected] Abstract— A new system of multicarrier modulation is described which takes advantage of the biorthogonality property to generalize the OFDM/OQAM technique into a Biorthogonal Frequency Div...

The residual echo enhancement (REE) procedure proposed in [1] is able to improve the acoustic echo cancellation (AEC) performance in a very noisy acoustic mixing environment by utilizing the natural learning ability of the least-mean square (LMS) algorithm without precise estimation of the signal statistics. We demonstrate in this paper that the technique can also be applied effectively in a mu...

The vital role of the ribosome in translating genetic information into proteins makes it an obvious target for various natural antibiotics and bacteriocins—protein toxins produced by bacteria to inhibit the growth of similar or closely related bacterial strains. Recent progress in ribosome crystallography has provided an enormous amount of structural detail, helping to explain how antibiotics i...

This paper presents a K-band Gilbert mixer in a 0.18μm CMOS technology by means of a π-Network and Post Distortion Cancellation (PDC) technique to achieve high gain, high linearity, and moderate noise figure. We use the parasitic capacitances that appear at nodes between RF and LO stage for implementing π-Network. Circuit analysis and MATLAB simulation show that the above technique is useful fo...

Single-polarization direct-detection transceivers may offer advantages compared to digital coherent technology for some metro, back-haul, access and inter-data center applications since they offer low-cost and complexity solutions. However, a direct-detection receiver introduces nonlinearity upon photo detection, since it is a square-law device, which results in signal distortion due to signal-...

MRI is a powerful technique for clinical diagnosis and materials characterization. Images are acquired in a homogeneous static magnetic field much higher than the fields generated across the field of view by the spatially encoding field gradients. Without such a high field, the concomitant components of the field gradient dictated by Maxwell's equations lead to severe distortions that make imag...