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 104 for “"modulation scheme"”.
-
A study of the minimum shift keying modulation scheme
… with the study of the Minimum Shift Keying (MSK) modulation scheme. The aspects considered are its operation under non-linear conditions as well as an investigation into the hardware implementation of both coherent and non-coherent MSK modems. The literature on digital data transmission and MSK in …
-
A Novel Chirp Slope Keying Modulation Scheme for Underwater Communication
A digital modulation method using Chirp-Slope Keying (CSK) is developed for coherent underwater acoustic communications. Effective signal detection is a critical stage in the implementation of any communications system; we will see that CSK solves some significant challenges to reliable detection. …
-
An Underwater Channel Model and Chirp Slope Keying Modulation Scheme Performance
… Keying (CSK) is a new and innovative digital modulation scheme for underwater data transmission. The underwater environment brings up several challenges to the manufacturing and operation of communication systems. This thesis shows through analysis and simulations the effectiveness of …
-
Investigation into variable shift keying using direct sequence spread spectrum techniques
… the research done into a relatively unknown modulation scheme called VPSK (Variable Phase Shift Keying) and the use of DSSS (Direct Sequence Spread Spectrum) techniques to achieve carrier synchronization and hence coherent demodulation in the receiver. VPSK is a new and relatively unknown …
-
Analysis and design of computationally efficient modulation schemes for Three Phase Three Switch rectifier for transportation electrification
… is achieved by Space Vector (SV) based modulation schemes. This thesis proposes a novel modulation technique for TPTS rectifier. The general SV modulation scheme xxvii xxviii used to control the TPTS is reviewed in this thesis. Numerous switching combinations possible for different …
-
Pilot patterns and power loading in NC-OFDM cognitive radios
… Frequency Division Multiplexing (OFDM) modulation. In the special case of cognitive radios however, the OFDM modulation scheme cannot simply be implemented without modification due to the huge change in the basic laws of the transmission paradigm. The main reason behind this is that the …
-
Orthogonal Frequency Division Multiplexing Modelling
… 5th Generation (5G) and beyond. One of the modulation strategies for upcoming 5G mobile communication technologies is FBMC. When compared to OFDM, which is utilised in Fourth Generation (4G) mobile communications technology, it employs multicarrier techniques that are immune to fading …
-
Analysis of transistor laser intra-cavity photon-assisted tunneling for direct voltage modulation
… of diode laser has been limited by its current modulation scheme in which the carrier recombination lifetime in the active region governs the ultimate speed of operation. The transistor laser, due to its enhanced carrier recombination in the bipolar junction transistor base region, is a …
-
An Investigation of Orthogonal Wavelet Division Multiplexing Techniques as an Alternative to Orthogonal Frequency Division Multiplex Transmissions and Comparison of Wavelet Families and Their Children
… represent significant challenges. Every modulation scheme used to date has had limitations, and the use of the Discrete Fourier Transform in OFDM (Orthogonal Frequency Division Multiplex) is no exception. The restriction on further development of OFDM lies primarily within the type of …
-
A Wireless Call Button Network Design
… of traditional Binary Phase Shift Keying (BPSK) modulation scheme for the radios is proposed. The proposed modulation scheme, like differential BPSK, can be detected non-coherently but it offers better performance than differential BPSK. Its implementation includes an innovative tracking …
-
Reduction of power supply EMI emission by switching frequency modulation
The effect of PWM frequency modulation on power supply conducted EM! noise emission is investigated. Significant reduction of emission is possible with PWM frequency modulation scheme. A forward converter is used to verify the effectiveness of the scheme. A guidance of parameter selection for noise …
-
Design and Analysis of Pulse -Width Modulation Techniques for Spectrum Shaping
… spectrum and then to realize it using a proper modulation scheme. The results of Pd-PWM and FM-PWM bring us one step closer to understanding how to meet this goal.
-
Harvesting time-frequency-space diversity with coded modulation for underwater acoustic communications
… have time-varying statistics, thus a coded modulation scheme optimally designed for a specific channel model will be suboptimal when the channel statistics change. A robust approach should use a coded modulation scheme that provides good performance in both additive white Gaussian noise …
-
On the Impact of Channel and Channel Quality Estimation on Adaptive Modulation
… wireless systems are designed by choosing a modulation scheme to meet worst case conditions and thus rely on power control to adapt to changing channel conditions. Adaptive modulation, however, exploits these channel variations to improve the spectral efficiency of wireless communications by …
-
A PAM Decomposition of Weak CPM
… Flight Termination System uses weak CPM as its modulation scheme and a limiter-discriminator as its demodulation scheme. A PAM representation of weak CPM was developed which representation provided the necessary componenents to build a simplified PAM-based receiver that outperformed the EFTS …
-
Experimental demonstration of cap transmitter using very high speed IC hardware description language (VHDL)
Carrierless Amplitude Phase (CAP) Modulation is a multidimensional and multilevel of modulation scheme which it is strongly inspired by QAM modulation scheme. CAP does not depend on a carrier and it is much simpler. Lots of CAP modulation experiments have been proposed and demonstrate but none of …
-
Design of sparse signaling schemes in fading wideband channels
… has resulted in a requirement for a different modulation scheme from previously used modulation schemes in order to succeed. Impulsive frequency shift keying, which is frequency shift keying with a duty cycle, is one such signaling scheme that has been shown to perform better than code division …
-
The development of a novel modem structure for connection of rural to diginet
… the use of partial response signalling as a modulation scheme in a modem structure. The modem structure consists of transmitter modulation and receiver demodulation sections only. The modem is designed to operate at data rates of 2400, 4800 and 9600 bps. The signalling format replaces the …
-
Spread spectrum modulation system for burst mode DC-DC converters
… audible range. This thesis explores a frequency modulation scheme and transient control that attenuates audible noise harmonics while minimizing the tradeoff for converter regulation, efficiency, and output voltage ripple.
-
Null power reallocation for data rate improvement in a wireless multicarrier system
… fading but simply choose a constant data modulation scheme and transmit power level for all sub carriers in the available signal bandwidth. Although these implementations maintain acceptable performance when channel conditions are poor, they do not efficiently utilize the full capacity of …
Page 1 of 6