In order to improve people’s living situation and decrease the use of fossil energy in the world, researchers’ attention has been focused on the energy side of the building sector. Especially single family houses in the Nordic countries Norway, Sweden and Finland have been given attention in the Increasing Energy Efficiency in Buildings (IEEB) project, with the purpose of increasing energy efficiency in buildings. In the project presented in this report, this has been studied by simulating a low energy single family house at different locations in Scandinavia, and applying the various national building codes to the house to see how it would match the energy requirements. The simulated locations included the different climates in Helsinki, Oulu (Finland), Oslo, Narvik (Norway), Piteå, Umeå, Karlstad, Borlänge, Stockholm and Kalmar (Sweden). The house fulfilled almost all the national energy requirements with more or less margin because of its low energy use. A comparison with actual measurements of the house did not match as good, because of uncertainty in measurement methods and climate aspects. The national building codes and climate in the Nordic countries turned out to be similar enough for a coordination of the building codes to be possible in the future.

The objective of this dissertation is to investigate incremental redundancy low-density parity-check (IR-LDPC) codes for hybrid forward error correction / automatic repeat request (HybridARQ) schemes. Powerful capacity-approaching IR-LDPC codes are one of the key functional elements in high-throughput HybridARQ schemes and provide a flexible rate-compatible structure, which is necessary for low-complexity HybridARQ schemes. This dissertation first studies the design and performance evaluation of IR-LDPC codes, which have good error rate performance at short block lengths. The subset codes of the IR-LDPC codes are compared to conventional random punctured codes and multiple dedicated codes. As a system model for this work, an adaptive LDPC coded system is presented. This adaptive system can confront the nature of time-varying channels and approach the capacity of the system with the aid of LDPC codes. This system shows remarkable throughput improvement over a conventional punctured system and, for systems that use multiple dedicated codes, provides comparable performance with low-complexity at every target error rate. This dissertation also focuses on IR-LDPC codes with a wider operating code range because the previous IR-LDPC codes exhibited performance limitation related to the maximum achievable code rate. For this reason, this research proposes a new way to increase the maximum code rate of the IR-LDPC codes, which provides throughput improvement at high throughput regions over conventional random punctured codes. Also presented is an adaptive code selection algorithm using threshold parameters. This algorithm reduces the number of the unnecessary traffic channels in HybridARQ schemes. This dissertation also examines how to improve throughput performance in HybridARQ schemes with low-complexity by exploiting irregular repeat accumulate (IRA) codes. The proposed adaptive transmission method with adaptive puncturing patterns of IRA codes shows higher throughput performance in all of operating code ranges than does any other single mode in HybridARQ schemes.

This paper present three kinds of nonlinear numerical methods to search for perfect complementary codes, include Newtonian Methods¡BLevenberg-Marquardt Algorithm and Trust-Regions. By searching for the solution of theses nonlinear equations, we can get complementary codes when setting for the length of element codes and the flock size. These search results is very generous. Complete complementary codes¡Bsuper complementary code and poly-phase complementary code are subsets of these searching results¡C These nonlinear equations are set to have ideal auto-correlation and cross-correlation properties, so the searching results of these nonlinear equations are still have perfect orthogonal complementary properties. Because the orthogonal complementary code is obtained via these nonlinear equations, the results are the most generous. So nonlinear numerical method is a good choice to search for another complementary code we don¡¦t know.

The most two important concern in CDMA code design, one is the properties of spreading codes correlation, and another one is the number of users. The correlation properties will influence BER (bit error rate) of the system directly, and the number of users will express the system capacity. In optical-CDMA system, optical spreading code is impossible to achieve idea correlation properties. Because of the optical sequence is consisted of ¡¨0¡¨¡B¡¨1¡¨. We prove it after. According to the result we can define the best properties of correlation of the optical complementary codes. The ideal of auto-correlation is 0( ) and the optimum cross-correlation is 1( ). According to the requirement of the optimum complementary codes we must first to decide the value of the best threshold and prove it. The properties of correlation are satisfied with optical prime-hopping complementary codes that we architecture. We analysis the performance of the prime-hopping complementary codes in optical CDMA. Because of the hits of MAI decrease we can support most number of users, so we can clearly find the system with the prime-hopping complementary codes has the better performance.

Stabilizer codes form a special class of quantum error correcting codes. Nonbinary quantum stabilizer codes are studied in this thesis. A lot of work on binary quantum stabilizer codes has been done. Nonbinary stabilizer codes have received much less attention. Various results on binary stabilizer codes such as various code families and general code constructions are generalized to the nonbinary case in this thesis. The lower bound on the minimum distance of a code is nothing but the minimum distance of the currently best known code. The focus of this research is to improve the lower bounds on this minimum distance. To achieve this goal, various existing quantum codes are studied that have good minimum distance. Some new families of nonbinary stabilizer codes such as quantum BCH codes are constructed. Different ways of constructing new codes from the existing ones are also found. All these constructions together help improve the lower bounds.

In Shannon’s seminal paper, “A Mathematical Theory of Communication”, he defined ”Channel Capacity” which predicted the ultimate performance that transmission systems can achieve and suggested that capacity is achievable by error-correcting (channel) coding. The main idea of error-correcting codes is to add redundancy to the information to be transmitted so that the receiver can explore the correlation between transmitted information and redundancy and correct or detect errors caused by channels afterward. The discovery of turbo codes and rediscovery of Low Density Parity Check codes (LDPC) have revived the research in channel coding with novel ideas and techniques on code concatenation, iterative decoding, graph-based construction and design based on density evolution. This dissertation focuses on the design aspect of graph-based channel codes such as LDPC and Irregular Repeat Accumulate (IRA) codes via density evolution, and use the technique (density evolution) to design IRA codes for scalable image/video communication and LDPC codes for distributed source coding, which can be considered as a channel coding problem. The first part of the dissertation includes design and analysis of rate-compatible IRA codes for scalable image transmission systems. This part presents the analysis with density evolution the effect of puncturing applied to IRA codes and the asymptotic analysis of the performance of the systems. In the second part of the dissertation, we consider designing source-optimized IRA codes. The idea is to take advantage of the capability of Unequal Error Protection (UEP) of IRA codes against errors because of their irregularities. In video and image transmission systems, the performance is measured by Peak Signal to Noise Ratio (PSNR). We propose an approach to design IRA codes optimized for such a criterion. In the third part of the dissertation, we investigate Slepian-Wolf coding problem using LDPC codes. The problems to be addressed include coding problem involving multiple sources and non-binary sources, and coding using multi-level codes and nonbinary codes.

Thesis (Ph. D.)--Oregon State University, 2010. / Printout. Includes bibliographical references (leaves 47-48). Also available on the World Wide Web.

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Multimedia services have become one of the major demands in wireless systems. As a result of growing demands for media services, traffic in wireless networks are increasing. Hence, optimization of multimedia delivery systems to efficiently consume the valuable transmission resources in wireless networks has gained a lot of interest. Raptor codes, with linear encoding and decoding time complexity are one branch of fountain codes (also known as rateless codes) which have found their ways in many recent communication standards as application layer forward error correcting (FEC) codes. Various attempts have been made in order to adapt these codes to wireless channels with their time varying nature. When multimedia delivery is targeted, some other issues such as delay should also be considered. Moreover, in multicast solutions, the system has to address demands of multiple clients. In this thesis, we investigate some optimization scenarios for wireless multimedia multicast systems wherein clients with heterogeneous channels and media quality demands subscribe to a video program. The video program is assumed as a multilayer source with possible spatial, temporal and fidelity layers. The point of optimization under various systems is to provide the clients of different quality constraints with their demanded services while imposing the minimum network/client cost (e.g. delay, power consumption, outage probability) or maximize the provided utility to the clients while considering their heterogeneous capabilities. To achieve these tasks, we study outage probability which serves as a measure to quantify the reliability of a service in a client's side. Packetized rateless multimedia multicast (PRMM) with few optimization criteria regarding the experienced delay in clients are studied and analytical solutions are obtained. A new optimization framework for rateless multimedia multicast is proposed in which, the provided utility to heterogeneous clients are maximized with respect to the clients channel and their quality demands. Application of this optimization in a rateless multimedia multicast system wherein the utility is defined based on perceptual quality experience of clients is also investigated. / Thesis (Master, Electrical & Computer Engineering) -- Queen's University, 2011-12-23 14:11:26.378

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