Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 74 for “"Amplitude-modulated"”.
-
Multiuser Detection for Pulse Amplitude Modulated Signals
Multiuser Detection (MUD) receiver techniques leverage the signal structure of overlapping transmissions to reduce inter-user interference and improve system performance. One main application for MUD research has been reducing inter-user interference in Code-Division Multiple Access (CDMA) channels …
-
Modulation techniques for data superposition on amplitude-modulated signals
Double-sideband amplitude-modulation is widely used because of its simplicity in transmission and reception, but in a number of applications the inclusion of a data channel has become an additional requirement. An additional data signal, transmitted with a normal AM broadcast signal, can be used by …
-
A device for quantizing, grouping, and coding amplitude-modulated pulses
Thesis (M.S.) Massachusetts Institute of Technology. Dept. of Electrical Engineering, 1949.
-
Quadrature amplitude modulated codes for orthogonal frequency division multiplexing applications
Thesis (M.Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2002.
-
Auditory-nerve fiber responses to amplitude modulated tones and multi-tonal stimuli
In normal-hearing ears, sound waves are amplified within the cochlea and a small fraction of the sound energy travels backward out into the ear canal, producing sounds known as "otoacoustic emissions" (OAE) that can be measured with a sensitive microphone. One class of OAE, called …
-
Lateralization of Sinusoidally - Amplitude-Modulated Tones: Effects of Spectral Locus and Temporal Variation
… variation, the lateralization of sinusoidally-amplitude-modulated tones. An acoustic pointing task was employed in which listeners varied the interaural intensitive disparity of a narrow band of noise (the pointer) so that it matched the intracranial position of a second, …
-
The Effect of Receiver Nonlinearity and Nonlinearity Induced Interference on the Performance of Amplitude Modulated Signals
… are power compression, which leads to amplitude and phase distortions in the received signal, and desensitization caused by a high powered interfering signal at an adjacent channel. As the RF spectrum becomes more crowded, the interference caused by these adjacent signals will become a …
-
Quadrature amplitude modulated codes with low peak-to-mean envelope power ratio for orthogonal frequency division multiplexing applications
… thesis investigates the properties of quadrature amplitude modulated (QAM) OFDM signals with low PMEPR, focusing in particular on signals based on 4-QAM and 16-QAM constellations. We construct and prove new code structures for sequences in 4-QAM and 16-QAM that result OFDM signals with low PMEPR. …
-
IDENTIFICATION OF Cav 3.2 T-TYPE VOLTAGE GATED CALCIUM CHANNELS AS KEY MEDIATORS OF TARGETED INHIBITION OF HEPATOCELLULAR CARCINOMA BY AMPLITUDE-MODULATED RADIOFREQUENCY ELECTROMAGNETIC FIELDS
Amplitude - modulated 27.12 MHz radiofrequency electromagnetic fields (AM RF EMF) delivered via a spoon - shaped antenna placed on the patient’s tongue results in shrinkage of the primary and metastatic tumors in patients with advanced hepatocellular carcinoma (HCC). The mechanism by which AM RF …
-
Outphase power amplifiers in OFDM systems
… power amplifiers for linear amplification. An amplitude modulated signal is first decomposed into two constant amplitude, phase modulated signals that can be amplified using two high efficiency switching power amplifiers. The two outputs are then recombined to restore the original amplitude …
-
Novel mechanisms of DC and kilohertz electrical stimulation
… effects of kilohertz electrical stimulation and amplitude-modulated waveform with kHz carrier frequency using a well-established animal model, hippocampal brain slice, 2) study the effect of tDCS on water exchange rate across the blood-brain barrier using an advanced MRI imaging technique in a …
-
Discriminability of Interaural Time Disparities by Normal Listeners and Listeners With High-Frequency Sensorineural Hearing Loss
… using a 500 Hz pure tone, a sinusoidally-amplitude-modulated 4 kHz tone and narrow band noises centered on either 500 Hz or 4 kHz.
-
Investigation into PRS-precoded, constant-envelope, continuous-phase digital modulation schemes
… to improve the spectral properties of Pulse Amplitude Modulated (PAM) digital transmission systems. This thesis investigation studied the effect of PRS on frequency- and phase-modulated carrier systems, in particular on their spectral performance and their maintenance of constant envelope.
-
A fourth order [Sigma] [Delta] bandpass modulator
… from a MEMS gyroscope. The modulator samples the amplitude-modulated signal at eight times the carrier frequency and achieves an SNR of 82dB with a sampling frequency of 640kHz and a bandwidtn o 1.oKnz. ms document snows that bandpass [Sigma] [Delta] modulation offers the advantage of a high …
-
Transmitter Design in a Commercial Marine, Single-Sideband Transceiver
… and a comparison of single sideband systems with amplitude modulated systems are also presented. The unique requirements of commercial, marine communications are considered and the method of their fulfillment in this transceiver is discussed. Circuitry common to both the receiver and the …
-
Short-visible-wavelength GHz Display
… and sensing require blue and ultraviolet light modulated in space and time. We propose and implement a strategy for fast, individual, coherent control of spatially-multiplexed channels at blue and ultraviolet wavelengths by combining an integrated photonic modulator array with a strong pump beam …
-
Structure of the polar electrojet antenna
… conductivity was periodically perturbed using amplitude-modulated radiation from the HAARP HF transmitter (1 MW power, 14 dB gain, 3.3-5.8 MHz carrier, 0.1-40 kHz modulation). The conductivity perturbations lead to perturbations to the natural flow of electrojet current in the lower ionosphere, …
-
Low-Intensity Ultrasonic Neuromodulation of the Rat Hippocampus
… to tFUS. Our working hypothesis in Aim 2 is that amplitude-modulated stimulation will produce qualitatively different outcomes compared to the conventionally tested pulsed and continuous wave stimulation. To test these hypotheses, we conducted electrophysiological recordings from the hippocampus …
-
Continuous detuning of an optical cavity with a Universally Tunable Modulator
… a cavity at a single detuned length using an amplitude modulated laser beam. However, there are many interesting applications, that would benefit from the use of a Universally Tunable Modulator (UTM), because it can create any ratio of amplitude to phase modulation. The unique transfer …
-
The amplitude-modulation-following response as an audiometric tool
The amplitude-modulation-following response (AMFR) is a sinusoidal auditory-evoked potential recorded to continuous, sinusoidally amplitude-modulated tones. Kuwada, et al. (1986) defined the AMFR and argued its audiometric utility. The current study consisted of four experiments designed to …
Page 1 of 4