Thesis (M.S.)--Oregon State University, 2005. / Printout. Includes bibliographical references (leaves 49-50). Also available on the World Wide Web.

Thèse (M.Sc.)--Université Laval, 2009. / Bibliogr.: f. [74]-76. Publié aussi en version électronique dans la Collection Mémoires et thèses électroniques.

Thesis (MS)--Montana State University--Bozeman, 2010. / Typescript. Chairperson, Graduate Committee: Richard Wolff. Includes bibliographical references (leaves 103-105).

Thesis (M.S.)--University of Wisconsin--Madison, 1969. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (M.S.)--University of Wisconsin--Madison, 1982. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 61-78).

No description available.

M.Ing. (Electrical & Electronic Engineering) / Coding is indispensable in modem communications and storage systems. For instance, a Reed-Solomon error-correction code ensures higher data integrity for the Compact Disc (CD) system. Modulation codes, such as the( d, k) codes, can furthermore be employed to enable synchronization between transmitter and receiver (or between the read and write processes in storage systems), and also to achieve compliance with bandwidth restrictions. In some cases, a 'combined' code is designed to function both as an error control code and a (d, k) modulation code. In this study, we consider such an existing class of error control (d, k) block codes. Of particular interest is the performance of these codes, determined mostly in terms of the probability of block error over certain selected channels. It is important to be able to judge or predict the performance of a communication system in terms of the probability of receiving incorrect information, and this probability depends not only on the specific error control code used, but also on the statistical structure of the channel error processes. The main contributions of this thesis are seen to be the following: 1) New codes and improvements on previous codes, originating from the generalization of existing theory. 2) Mathematical bounds and approximations on block error rates, compared with measured results from computer simulations.

M.Ing. (Electrical and Electronic Engineering) / The South African Railways covers a total distance of some 24 000 km, making use of a signalling network of 1000 interlocking systems. This comprises of the order of 1000 signalling houses each with its own unlnterruptible power supply system of which a DC·AC converter Is one of the components. Due to the requirements by Spoomet, high frequency (ultrasonic) chopper technology had to be used. This treatise describes the design and development of a 3 kVA composite DC·AC converter with an ultrasonic AC link for this application. In the primary converter (centre tapped topology) ZVS Is achieved by good circuit layout and controlled transformer capacitance. As a result the performance of the converter was improved with regard to efficiency and switching transients compared to the conventional hard switched converter. The four pulse topology with an output LC·filter was used for the secondary converter. Due to the modulation technique being used, the load perceived the switching frequency as 20kHz while the actual switching frequency was only 10kHz. In this way switching losses were kept within reasonable limns as well as satisfying the low audible noise requirement. The stability of the LC·filter was achieved with a current feedback loop. The literature describes the capacitor current being used in the feedback loop. In this case the Inductor current was used with the advantage of output short circuit protection without an additional current measurement. Apart from the advantages of small weight and volume from a maintenance point of view, the composite DC·AC converter also achieved high efficiency (> 85%) over a wide load range (10%-100% of full load).

Typescript, etc.

Spatial Modulation (SM) is a spatial multiplexing technique designed for MIMO systems where only one transmit antenna is used at each time. It is considered to be an attractive choice for future wireless communication systems as it reduces Inter Channel Interference (ICI) while maintaining high energy efficiency. It can achieve this goal by mapping block of data bits into constellation points in the spatial and signal domain. Combining this innovative method with multiple access techniques could improve the system performance and enhance the data rate. In Code Division Multiple Access (CDMA) method employing parity bit permutation spreading, the bit error rate (BER) performance could be improved by using the parity bits to select the spreading sequence to use at each signalling interval. In this thesis, a new system model based on SM and CDMA employing parity bit permutation spreading is proposed and investigated. The proposed system takes advantage of the benefits of both techniques. In this system, in addition to use the parity bits to select the spreading sequences, same concept is used to select the combination of antennas to activate at each time instant. By doing so, a reduction of power consumption, Inter-Channel and Inter Symbol Interference effect can be achieved while keeping a certain diversity order compared to SM. Multiuser scenario is also discussed in order to investigate the multiple access interference (MAI) effects in synchronous transmission. In such case, the receiver estimates the desired user's information by considering the other users' signal as additional noise. Simulation results of the proposed MIMO-CDMA system employing permutation spreading show, for single user and multiuser, a significant improvement of the BER performance in low signal to noise ratio (SNR) when SM is implemented.