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This is a commentary on Meyer, Sun, and Martin (2020), Synchronous, but not entrained: exogenous and endogenous cortical rhythms of speech and language processing. [ABSTRACT FROM AUTHOR]

The inherent sensitivity of orthogonal frequency division multiplexing (OFDM) systems to any frequency shift in the signal makes their design very challenging. In OFDM systems, the frequency shift may be due to instability of transmitter/ receiver oscillators or because of fading channel. The frequency shift in the signal destroys the orthogonality among subcarriers and results in intercarrier interference (ICI), which affects the system performance severely. A number of solutions are available to mitigate the effect of ICI. The existing ICI mitigation techniques include frequency equalization, time domain windowing, ICI self-cancellation, coding, etc., Among several ICI reduction methods, ICI self-cancellation scheme has received much attention due to its simplicity. The ICI mitigation schemes that depend on carrier frequency offset (CFO) correction at the transmitter are effective under high signal-to-noise ratio (SNR) scenario and those that depend on CFO estimation and correction at the receiver have additional computational complexity and some sort of data symbol redundancy. In this paper, a bandwidth-efficient ICI reduction method for M-ary QAM signals is proposed. The present method is effective in low SNR environment. This method reduces the effect of ICI and improves the performance of the system in terms of bit error rate. It is shown that the proposed ICI cancellation method considerably outperforms the existing ICI self-cancellation schemes in the presence of small CFO while maintaining the throughput level. [ABSTRACT FROM AUTHOR]

This paper mainly focuses on the InGaP/GaAs hetero-junction bipolar transistor (HBT) which is fully based on integrated X-band monolithic microwave integrated circuit (MMIC) differential voltage controlled oscillator (VCO). This VCO is designed and fabricated with HBT tripler circuit techniques for triple multiplication of frequency component of core VCO output. The HBT-based differential VCO circuitry consists of a differential VCO and two triplers. The VCO design is concentrated in high oscillation frequency with the low phase noise by using the tripler circuit. The tripler is the smallest in size, with the lowest power consumption and X-band application frequency. The lowest frequency characteristic enables MMIC tripler differential VCO to be implemented in phase locked loop (PLL) circuit. This approach solves the problem of stable local oscillator (LO) signal. The differential VCO is based on the capacitive cross-coupled differential topology. The core differential VCO achieves the oscillation frequency of 3.583 GHz with the output power of 3.65 dBm, the phase noise of -96.7 dBc at 100 kHz offset and -118.85 dBc at 1 MHz offset at 2.9 V and 30 mA bias condition. At 5 dBm input power, the tripler's conversion loss is less than 30 dB with bias condition as 3 V and 26 mA. The tripler diferential VCO generates the oscillation frequency of 10.75 GHz with the output power of -25 dBm. The total size of fabricated MMIC tripler differential VCO is 995 × 850 μm2 area. [ABSTRACT FROM AUTHOR]

To compensate the time synchronisation error, the direct-path signal is used in some bistatic synthetic aperture radar (BiSAR) systems. It turns out that an additional error is added in the translational-variant BiSAR echo data when the direct-path signal is directly used to compensate the time synchronisation error by aligning the direct-path signal in the same row. Since the additional error is modulated on the phase history of the direct-path signal, it can be estimated by unwrapping the phase history. Therefore, a time synchronisation error correction method using phase history of direct-path signal is presented, and it can compensate the additional error correctly. [ABSTRACT FROM AUTHOR]

An architecture for on-line learning of time series prediction is presented which uses a series of echo state networks (ESNs). Each ESN learns to predict an error correction term for the previous ESN. This technique is demonstrated to improve prediction accuracy for on-line learning of the Mackey-Glass chaotic oscillator. The results are compared to other architectural configurations to show that the improved performance emerges from sequential ESN error correction. A new recurrent network structure is shown to be a useful simplification of the usual ESN reservoir. [ABSTRACT FROM AUTHOR]

A new method for locating the break point of a cable has been developed. It operates by application of the principle of the transmission line oscillator. Coaxial cables of four different lengths (1.5 m, 5 m, 10 m, 20 m) were measured in accordance with this method. The results show high precision (deviation <0.5 cm) and accuracy (error ≤3 cm). [ABSTRACT FROM AUTHOR]

In this paper, we propose two new techniques to significantly improve the frequency resolution of a digital look-up-table (LUT) tunable sinusoidal oscillator. The proposed techniques are based on storing and reading the sine and cosine components of two sinusoidal functions that are not harmonically related and then evaluating the sine or cosine of the phase difference. The proposed techniques are shown to be very efficient in increasing the effective table length and, hence, the frequency resolution of the oscillator. Further performance improvement can be achieved by using interpolation methods as demonstrated. Simulation results verify the analytical results and show that the total harmonic distortion of the generated sinusoid is of the same order as that of the conventional digital LUT tunable sinusoidal oscillator. [ABSTRACT FROM AUTHOR]

An integrable current-tunable sinusoidal quadrature oscillator is presented. A current-tunable all-pass filter using a signal-differencing technique is realized as the frequency-selective network. The implementation is fully balanced so as to enable accurate quadrature signals with symmetry. The oscillation frequency is current-tunable over a wide-frequency sweep range of approximately three orders of magnitude. The quadrature signals possess the amplitude matching and the quadrature phase matching of better than 0.004 dB and 0.15, respectively. The maximum useful frequency of oscillation is in excess of 8 MHz. Total harmonic distortions are less than 0.5%. [ABSTRACT FROM AUTHOR]

A Lamb wave device using a PbZrO[sub 3]-based piezoelectric ceramic substrate and its application to an oscillator are described. The Lamb wave device which is practically in single-mode operation uses the zeroth-order symmetrical (S[sub 0]) mode. A delay line oscillator is composed of the S[sub 0] mode device, an amplifier and an electrically controllable phase shifter, whose oscillation frequency varies with the applied voltage. The oscillator has fine frequency modulation characteristics in a wide frequency range from DC to 100 kHz. The device performance is useful for FM signal processing or voltage sensing. [ABSTRACT FROM AUTHOR]

In this paper three configurations of a SAW injection locked oscillator (ILO) in which the injector is built-in are proposed. The built-in injector eliminates a directional coupler or an isolator commonly used in SAW ILOs. These built-in injectors are fabricated along with the delay line on a YZ LiNbO[sub 3] substrate. Experimental results obtained for a 21·7 MHz oscillator using these three configurations are presented and compared. [ABSTRACT FROM AUTHOR]

Focuses on the use of a chaotic oscillator as a musical signal generator in an interactive performance system. How to set up experimental and performance environments for musical signal generation with a continuous chaotic system; Physical properties and nonlinearity of the oscillator; Vector field description of signals from the oscillator.

A generator of the harmonic signal is described for frequencies in the acoustic region with the reference stabilized amplitude, linear frequency scale and total harmonic distortion below 2 10. The signal is produced as the solution of the corresponding differential equation where the constant amplitude is maintained by periodic control of the first derivative value x(t) at the moments when x(t) crosses zero and has a positive slope. [ABSTRACT FROM AUTHOR]

A new variable frequency oscillatory system is described. For certain system conditions the circuit produces a sine wave oscillation whose frequency is varied over a wide range from a very low to a high value simply by varying the gain of an amplifier rather than by changing the circuit time constant and accordingly no ganged condensers are used. Another important feature of the circuit is that the generation of a very low frequency oscillation is possible without incorporating a large value of the RC product. The oscillator utilizes air amplitude stabilizer operating on the controlled linear resistance of the initial region of the characteristic of a junction FET. The frequency relation is derived and the results are compared with experiment and found in agreement. [ABSTRACT FROM AUTHOR]

While generating very low frequency sinusoidal voltage, using operational amplifiers, one experiences difficulties in stabilizing the amplitude and every endeavour has been made to get a satisfactory solution. The paper describes one method by which stable oscillation can be obtained to a frequency as low as 0.01 c/s. The oscillator consists of two integrators and one sign changer interconnected in the form of a closed loop so as to solve a second-order differential equation. The amplitude is stabilized with the help of an extra stabilizing loop which consists of a squaring network. A brief analysis of the oscillator has been carried out and the precautions that have to be taken for improving the oscillator performance are discussed. [ABSTRACT FROM AUTHOR]

Investigates the performance of the Darlington composite transistor oscillator. Research on the Darlington composite transistors; Analysis on the schematic diagram of the Darlington transistor oscillator; Assessment on the frequency oscillation of single stage transistor oscillator.

Proposes a complex digital oscillator structure consisting of two integrators and two multipliers. Sensitivity to coefficient quantization of the proposed structure; Capability of generating sinusoidal signals in a wide range of frequencies and with high frequency resolution; Implementation on already available digital signal processors.

Discusses a frequency modulated phono-oscillator which can reduce records through a frequency modulation receiver without wired connections in the article 'FM 'Wireless' Record Player uses Capacity Phono-Pickup,' by Arthur Trauffer.

Presents an article 'A New Direct Crystal-Controlled Oscillator with Ultra-Short-Wave Frequencies,' by W.P. Mason and I.E. Fair, published in the October 1942 issue of the journal, 'Proceedings of the I.R.E.'