orthogonal frequency division multiplexing (ofdm) has become a promising method for many wireless communication applications. however, one main drawback of ofdm systems is the high peak-to-average power ratio (papr). selected mapping (slm) is a well-known technique to decrease the problem of high papr in ofdm systems. in this method, transmitter is obliged to send some bits named side informati...

The transimpedance or current feedback operational amplifier (CFB op-amp) is reviewed and compared to a conventional voltage mode op-amp using an analysis emphasizing the basic feedback characteristics of the circuit. With this approach the paradox of the constant bandwidth obtained from CFB op-amps is explained. It is demonstrated in a simple manner that the constant gain-bandwidth product of ...

Theoretical investigation of the use of feedback around the limiter for improving the capture conditions at the input to the limiter has led to the formulation of a simple theory that unfolds some remarkable properties hitherto unreported. Contrary to the claim of R. M. Wilmotte (1), who made the first (and apparently only) around-the-limiter feedback proposal that exists in published work, thi...

We propose an experiment on quantum feedback control of a solid-state qubit, which is within the reach of the present-day technology. Similar to an earlier proposal fR. Ruskov and A. N. Korotkov, Phys. Rev. B 66, 041401sRd s2002dg, the feedback loop is used to maintain coherent oscillations in a qubit for an arbitrarily long time; however, this is done in a significantly simpler way, which ease...

For users with motion impairments, the standard keyboard and mouse arrangement for computer access often presents problems. Other approaches have to be adopted to overcome this. There is evidence to suggest that increasing the degrees-of-freedom, and hence bandwidth, of humancomputer interaction (HCI), can improve interaction rates if implemented carefully. Haptic feedback is not really exploit...

While existing research shows that reactive congestion control mechanisms are capable of providing high video quality and channel utilization for point-to-point real-time video, there has been relatively little study of the reactive congestion control of point-to-multipoint video, especially in ATM networks. Problems complicating the provision of multipoint, feedback-based real-time video servi...

By frequency-band extracting, we experimentally and theoretically investigate time-delay signature (TDS) suppression entropy growth enhancement of a chaotic optical-feedback semiconductor laser under different injection currents feedback strengths. The TDS are quantified by the peak value autocorrelation function difference permutation at delay time. At optimal extracting bandwidth, measured is...

Although high bandwidth for the pressure tracking of hydraulic actuators is highly desirable in many industrial applications, it has been a challenge to achieve, mainly due to the natural velocity feedback path in these actuators. In this paper, we investigate the extent to which a fixed-gain linear controller designed based on quantitative feedback theory (QFT) can improve the pressure trackin...

We study 1/f and narrow-bandwidth noise in precision oscillators based on high-quality factor resonators and feedback. The dynamics of such an oscillator are well described by two variables, an amplitude and a phase. In this description we show that low-frequency feedback noise is represented by a single noise vector in phase space. The implication of this is that 1/f and narrow-bandwidth noise...