During the last few years, the existence of high levels of man-made low frequency noise (O-100 Hz), and in particular infrasonic noise, has been reported in many environments. An effort has been made over the last decade to discover whether such high levels of low frequency noise are significant. A review of the effects of low frequency noise indicates that the effects are similar to those of h...

In wireless networks, different links often have different signal power to noise power ratios (SNRs). SNR affects the reliability and throughput of a link. Current wireless systems adapt transmission power, modulation or coding to improve reliability and throughput, based on link SNR. However, all these systems transmit a modulated symbol for a fixed duration across all links. Theory and system...

In this paper, a novel two-step non-data-aided (NDA) signal to noise ratio (SNR) estimator is proposed to improve its accuracy in the low SNR region of orthogonal frequency division multiplexing (OFDM) signals. The two-step estimator consists of a coarse estimation followed by a refinement step. In the first step, three linear independent coarse estimations of the signal and noise power are obt...

This paper demonstrates the execution and performance of frequency hopping spread spectrum system employing noncoherent frequency shift keyed (NCFSK) modulation. Fast frequency hopping is exploited as a diversity technique over flat Rayleigh fading channel with partial band noise jamming and additive white noise Gaussian (AWGN). The potentiality of the aforementioned system has then, ascertaine...

Error rates of orthogonal frequency division multiplexing (OFDM) signals are considered for system using multichannel reception with maximum ratio combining (MRC) receivers in Nakagami-m fading generated by sum of sinusoidal method using Rayleigh and Ricean channel. The paper also discusses the effect of frequency offsets, nakagami-m parameter m on OFDM systems. Also effect of frequency offset ...

in this research, active capacitance circuit and the feature of negative resistance are analysed in details. also, a new active filter is presented based on active capacitance circuit. for simulations, we used matlab and advanced design system(ads). proposed active filter (rf) is a narrow band filter. the results of simulation shows some aspects of sustainability and low noise feature. the circ...

Sounds can induce autonomic responses in listeners. However, the modulatory effect of specific frequency components of music is not fully understood. Here, we examined the role of the frequency component of music on autonomic responses. Specifically, we presented music that had been amplified in the high- or low-frequency domains. Twelve healthy women listened to white noise, a stress-inducing ...