Engineering Commons^™

Investigation Of Pre-Detection Signal Processing Of Pseudonoise Communication Signals In The Presence Of Additive White Gaussian Noise And Cw And Bursty Interference, Israel Mayk

Dissertations

By comparison to conventional communication systems, spread-spectrum systems are known to be less affected by interference because of their large dimensionality in signal space. Nevertheless, significant performance degradation is experienced when large interference exists in a few or even one signal coordinates. In this case, interference reduction techniques are also known to provide additional processing gain. A novel class of pseudonoise (PN) invariant algorithms is derived to reduce the impact of interference and restore much of the structure of PN signals received in the presence of interference and noise. A PN signal received by a pre-detection signal process (PDSP) implementing …

The Effect Of A Higher Order Pole On The Optimum Design Of Minimum Threshold Phase Locked Detectors, Bernard Zivotofsky

Dissertations

The phase lockedloop is widely used as an FM demodulator known as a phaselocked detector (PLD). It is particularly useful in the detection of weak signals because lower threshold is possible with a PLD than with a conventional limiter discriminator. An enhanced version PLD known as an extended range phaselocked detector (ERPLD) is capable of further threshold reduction. The most popular PLD is a second order type I system employing a loop filter having one real pole and one real zero.

One implementation of an ERPLD calls for the addition of a differentiator to the standard loop filter which replaces …

Digital Fm-Demodulation Using Digital Signal Processing Techniques, Peter Wagner

Theses

This thesis presents the results of research in the area of digital demodulation of FM signals. The first part of the thesis describes the performance of digital Hilbert-transformers and Differentiators that are optimized in a determined bandwidth. These digital filters are used to build a digital Klapper-Kratt detector. According to this procedure, the coefficients of the digital Klapper-Kratt detectors up to the filter length N=25 are calculated and the resulting discriminator ripple computed and evaluated. One suggested algorithm gives the opportunity to balance the detector at a certain center-frequency. The major part of this thesis describes a new approach towards …

Digitally Implemented Klapper-Kratt Fm Detector Using The Intel-292o Digital Signal Processor, Chang-Hwan Park

Theses

This thesis describes and analyses a digitally implemented FM detector, which is a new member of the family of FM detectors introduced by Drs. Klapper and Kratt.

The properties of the new detector are low delay, excellent sensitivity, extreme linearity, and compatibility of components with integrated circuit technology.

A working model is implemented by adapting FIR digital s signal processing methods, and is realized using the Single-Chip Digital Signal Processor Intel-2920 which is comprised of micro-processor, scratch-pad data RAMs, program store EPROMs, A/D and D/A conversion circuitry, and I/O circuitry.

The performance of the working model shows very good linearity …