Active noise control technology is an attractive solution for attenuation of low frequency noise in enclosures. In terms of control strategies, feedforward control has often been used. While feedforward control has many advantages, its success relies on the availability of causal reference signals which have to be highly correlated to the noise to be cancelled. For some applications such as att...

We present results of adaptive canceller experiments at the Rapid Prototyping Array which compare the quality of interference suppression achieved in the voltage and power domains. It is shown that if the optimal complex weights used to model the interference are stationary over the length of the time average, then the same level of suppression is achieved. A limitation of both methods is that ...

This paper describes an approach to normalize the noise level of a speech signal at the outputs of the Mel scaled filter–bank used in MFCC–feature extraction. An adaptive normalizing function that distinguishes between speech and silence parts of the signal is used to normalize the noise level, without altering the speech parts of the signal. This technique is combined with an adaptation of the...

The harmonics-to-noise ratio (HNR) has been shown to provide a useful, non-invasive index for assessing and analyzing voice disorders. As such, a valid and reliable method for estimating levels of noise and hence HNR, in human voice is important for effective evaluation and management of voice pathology. An objective method to determine the accuracy of two cepstrum-based techniques described in...

We propose a new, low-complexity solution to realize multi-input-bit gates acting on exponentially large superpositions in noise-based logic processors. Two examples are shown, the NOT gate and the CNOT gate. The operations can be executed and repeated with polynomial time and hardware complexity. The lack of solution of this problem had been one of the major issues prohibiting the efficient re...

There are strong noise components included in the reference signal and the received signal of the ultrawideband (UWB) differential transmitted reference (DTR) autocorrelation receiver, which impact on the receiver's performance seriously. Therefore this paper proposes a autocorrelation receiver based on average differential transmitted reference (ADTR). This receiver averages the received signa...

We demonstrate an easy-to-manufacture 25-mm-long ultra-stable optical reference cavity for transportable photonic microwave generation systems. Employing a rigid holding geometry that is first-order insensitive to the squeezing force and a cavity geometry that improves the thermal noise limit at room temperature, we observe a laser phase noise that is nearly thermal noise limited for three freq...

This paper focuses on three commonly used sensorless methods based on high-frequency signal injection; namely, the rotating sinusoidal injection in the stationary reference frame, the pulsating sinusoidal injection in the estimated synchronous reference frame, and the pulsating square wave injection in the estimated synchronous reference frame. Although these methods have found applications in ...