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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

High Rate Digital Demodulator ASIC

Ghuman, Parminder, Sheikh, Salman, Koubek, Steve, Hoy, Scott, Gray, Andrew 10 1900 (has links)
International Telemetering Conference Proceedings / October 26-29, 1998 / Town & Country Resort Hotel and Convention Center, San Diego, California / The architecture of the High Rate (600 Mega-bits per second) Digital Demodulator (HRDD) ASIC capable of demodulating BPSK and QPSK modulated data is presented in this paper. The advantages of all-digital processing include increased flexibility and reliability with reduced reproduction costs. Conventional serial digital processing would require high processing rates necessitating a hardware implementation other than CMOS technology such as Gallium Arsenide (GaAs) which has high cost and power requirements. It is more desirable to use CMOS technology with its lower power requirements and higher gate density. However, digital demodulation of high data rates in CMOS requires parallel algorithms to process the sampled data at a rate lower than the data rate. The parallel processing algorithms described here were developed jointly by NASA’s Goddard Space Flight Center (GSFC) and the Jet Propulsion Laboratory (JPL). The resulting all-digital receiver has the capability to demodulate BPSK, QPSK, OQPSK, and DQPSK at data rates in excess of 300 Mega-bits per second (Mbps) per channel. This paper will provide an overview of the parallel architecture and features of the HRDR ASIC. In addition, this paper will provide an overview of the implementation of the hardware architectures used to create flexibility over conventional high rate analog or hybrid receivers. This flexibility includes a wide range of data rates, modulation schemes, and operating environments. In conclusion it will be shown how this high rate digital demodulator can be used with an off-the-shelf A/D and a flexible analog front end, both of which are numerically computer controlled, to produce a very flexible, low cost high rate digital receiver.
2

Optimum detection of differentially-encoded M-ary phase-shift keying in a dispersive aeronautical channel

Rodenbaugh, John Irvin. January 2002 (has links)
Thesis (M.S.)--Ohio University, June, 2002. / Title from PDF t.p. Includes bibliographical references (leaves 47-48).
3

Amplitude estimation of minimum shift keying in co-channel interference /

Ekanthalingam, Ravikanth. January 2004 (has links)
Thesis (M.S.)--Ohio University, November, 2004. / Includes bibliographical references (p. 76-77)
4

Amplitude estimation of minimum shift keying in co-channel interference

Ekanthalingam, Ravikanth. January 2004 (has links)
Thesis (M.S.)--Ohio University, November, 2004. / Title from PDF t.p. Includes bibliographical references (p. 76-77)
5

Digital Radio Implementation for NASA S-Band Space Network Transceiver

Berhanu, Samuel, Neupane, Kamal 10 1900 (has links)
The system diagrams for the digital radio compatible with NASA's S-Band Space Network operating from 2025.8 - 2117.9 MHz (forward link) to 2200 - 2300 MHz (return link) are presented. The digital radio implementation includes binary phase shift keying (BPSK), quadrature phase shift keying (QPSK) and staggered quadrature phase shift keying (SQPSK). We have derived the system requirements for these modulation schemes from the Space Network User Guide (SNUG) and thereafter, derived system diagrams for the communication links. The designed system diagrams for the transceiver were implemented using Simulink models and USRP2 platform.
6

TURBO-CODED APSK FOR TELEMETRY

Shaw, Christopher, Rice, Michael 10 1900 (has links)
ITC/USA 2007 Conference Proceedings / The Forty-Third Annual International Telemetering Conference and Technical Exhibition / October 22-25, 2007 / Riviera Hotel & Convention Center, Las Vegas, Nevada / This paper considers the use of Amplitude-Phase Shift Keying (APSK) for a telemetry system. Variable rate turbo codes are used to improve the power efficiency of 16- and 32-APSK. We discuss compensation techniques for power amplifier nonlinearities. Simulation results show the improved spectral efficiency of this modulation scheme over those currently defined in telemetry standards.
7

FQPSK ANALOG/DIGITAL IMPLEMENTATIONS FOR LOW TO ULTRA HIGH DATA RATES IN 1Gb/s RANGE SYSTEMS

Chen, Dijin, McCorduck, James A., Feher, Kamilo 10 1900 (has links)
International Telemetering Conference Proceedings / October 20-23, 2003 / Riviera Hotel and Convention Center, Las Vegas, Nevada / For simpler implementations of ultra high bit rate systems, combined analog/digital techniques, described here in, provide implementations with the smallest number of component count utilizing minimal “real-estate” and smallest DC power. While digital implementations with tradition Read Only Memory (ROM) and Digital to Analog Converters (DAC’s) have been proven in several commercial, NASA -CCSDS recommended, and U.S. DoD-IRIG standardized Feher’s QPSK (FQPSK) [2,3] products, such implementations can be further simplified, and in particular for ultra high bit rate product applications. Several waveform generating techniques such as linear approximation, analog approximation and mixed analog and linear approximations are investigated using preliminary simulation results.
8

FQPSK DEVELOPMENTS RECOMMENDED FOR CCSDS STANDARDIZATION BY NASA JPL

Martin, Warren L. 10 1900 (has links)
International Telemetering Conference Proceedings / October 23-26, 2000 / Town & Country Hotel and Conference Center, San Diego, California / In 1992, international space agencies became concerned that increasing frequency band congestion, together with attempts by the mobile telephone industry to obtain additional bandwidth, would result in substantially more interference incidents. The CCSDS undertook a technical study to identify and recommend more bandwidth efficient modulation schemes, which would permit more users to co-exist in a frequency band while reducing interference incidents. This paper describes the contribution of the Jet Propulsion Laboratory (JPL) to that effort.
9

ENHANCED PERFORMANCE OF FQPSK-B RECEIVER BASED ON TRELLIS-CODED VITERBI DEMODULATION

Lee, Dennis, Simon, Marvin, Yan, Tsun-Yee 10 1900 (has links)
International Telemetering Conference Proceedings / October 23-26, 2000 / Town & Country Hotel and Conference Center, San Diego, California / Commercial FQPSK-B receivers traditionally use symbol-by-symbol detection and have a 2 dB Eb=No loss relative to ideal QPSK at a bit error rate (BER) of 10^(-5). An enhanced FQPSK-B receiver using a Viterbi algorithm (VA) to perform trellis decoding is simulated and shown to have a 1.2 dB Eb=No improvement over symbol-by-symbol detection for 10^(-5)5 BER at the cost of increased complexity. A simplified Viterbi receiver with a reduced trellis and significantly less complexity is introduced with only a slight BER degradation compared to the full Viterbi receiver. In addition, a theoretical bit error probability expression for the symbol-by-symbol FQPSK-B receiver is derived and compared with simulation results.
10

A remodulation scheme for wavelength-division multiplexing passive optical network using time-interleaved differential phase shift keying modulation format.

January 2011 (has links)
Li, Pulan. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (p. 60-66). / Abstracts in English and Chinese. / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Overview of wavelength division multiplexed passive optical network (WDM-PON) and colorless optical network unit (ONU) --- p.1 / Chapter 1.2 --- Implementation of colorless ONU --- p.4 / Chapter 1.3 --- Rayleigh backscattering in WDM-PON --- p.6 / Chapter 1.4 --- Motivation of this thesis --- p.9 / Chapter 1.5 --- Outline of this thesis --- p.11 / Chapter Chapter 2 --- Previous works of remodulation for WDM-PON --- p.12 / Chapter 2.1 --- Introduction --- p.12 / Chapter 2.2 --- Devices utilized by colorless ONU in remodulation schemes --- p.13 / Chapter 2.2.1 --- Injection-locked Fabry-Perot laser diode at ONU --- p.13 / Chapter 2.2.2 --- Reflective semiconductor optical amplifier --- p.15 / Chapter 2.2.3 --- Reflective electro-absorption modulator and semiconductor optical amplifier (REAM-SOA) --- p.17 / Chapter 2.3 --- Modulation methods in remodulation schemes --- p.18 / Chapter 2.4 --- Summary --- p.23 / Chapter Chapter 3 --- A remodulation scheme based on time-interleaved DPSK modulation format --- p.25 / Chapter 3.1 --- Introduction --- p.25 / Chapter 3.2 --- Operation principle: time-interleaving technology for phase-modulated signal --- p.27 / Chapter 3.3 --- System architecture --- p.28 / Chapter 3.4 --- Experimental results and discussion --- p.31 / Chapter 3.5 --- Effect of timing misalignment on proposed remodulation scheme --- p.33 / Chapter 3.6 --- Summary --- p.35 / Chapter Chapter 4 --- Enhanced Tolerance to Rayleigh Backscattering in Remodulation Scheme Using Time-Interleaved DPSK Format --- p.37 / Chapter 4.1 --- Introduction --- p.37 / Chapter 4.2 --- Studies on Rayleigh backscattering suppression in optical domain --- p.39 / Chapter 4.2.1 --- RB suppression in carrier-distributed schemes --- p.39 / Chapter 4.2.2 --- RB suppression in remodulation schemes --- p.40 / Chapter 4.2 --- Experimental setup and results --- p.42 / Chapter 4.3 --- Discussion on RB suppression effect of the proposed scheme --- p.46 / Chapter 4.3.1 --- Theoretical study and simulation results --- p.46 / Chapter 4.3.2 --- Experimental demonstration of spectral relationship between signals and RB crosstalk --- p.49 / Chapter 4.4 --- Summary --- p.53 / Chapter Chapter 5 --- Conclusion and Future Works --- p.55 / Chapter 5.1 --- Conclusion of this thesis --- p.55 / Chapter 5.2 --- Future works --- p.57 / List of Publications --- p.59 / Bibliography --- p.60

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