Intelligent Processing in Wireless Communications Using Particle Swarm Based Methods

There are a lot of optimization needs in the research and design of wireless communica- tion systems. Many of these optimization problems are Nondeterministic Polynomial (NP) hard problems and could not be solved well. Many of other non-NP-hard optimization problems are combinatorial and do not have satisfying solutions either. This dissertation presents a series of Particle Swarm Optimization (PSO) based search and optimization algorithms that solve open research and design problems in wireless communications. These problems are either avoided or solved approximately before. PSO is a bottom-up approach for optimization problems. It imposes no conditions on the underlying problem. Its simple formulation makes it easy to implement, apply, extend and hybridize. The algorithm uses simple operators like adders, and multipliers to travel through the search space and the process requires just five simple steps. PSO is also easy to control because it has limited number of parameters and is less sensitive to parameters than other swarm intelligence algorithms. It is not dependent on initial points and converges very fast. Four types of PSO based approaches are proposed targeting four different kinds of problems in wireless communications. First, we use binary PSO and continuous PSO together to find optimal compositions of Gaussian derivative pulses to form several UWB pulses that not only comply with the FCC spectrum mask, but also best exploit the avail- able spectrum and power. Second, three different PSO based algorithms are developed to solve the NLOS/LOS channel differentiation, NLOS range error mitigation and multilateration problems respectively. Third, a PSO based search method is proposed to find optimal orthogonal code sets to reduce the inter carrier interference effects in an frequency redundant OFDM system. Fourth, a PSO based phase optimization technique is proposed in reducing the PAPR of an frequency redundant OFDM system. The PSO based approaches are compared with other canonical solutions for these communication problems and showed superior performance in many aspects. which are confirmed by analysis and simulation results provided respectively. Open questions and future Open questions and future works for the dissertation are proposed to serve as a guide for the future research efforts

The Sense of Community with a Shared Future for Mankind of Dragon Blade

Community is the way for human beings to survive and the only way for individuals to achieve free and comprehensive development. The concept of a community with a shared future for mankind is China’s new proposal in the new era, based on the concern for humanity. It emphasizes the concept of global governance featuring extensive consultation, joint contribution and shared benefits, and the concept of equality, mutual learning, dialogue and inclusiveness among civilizations. The movie Dragon Blade takes the ancient Silk Road as the background and the collision and reconciliation between Chinese and Western civilizations as the main line. It reflects the Chinese nation’s pursuit of peace and shows the cultural exchange and reference between China and the West. It reveals the sense of extensive consultation, joint contribution and shared benefits, and finally formed a solid friendship between China and the West under the sense of a community with a shared future for mankind. The film fully embodies the sense of a community with a shared future for mankind.

Analysis on Lolita’s Tragic Fate and Self-Redemption From the Perspective of Sphinx Factor

Lolita’s life is short and tragic. The teenage girl’s Sphinx factor ties her fate to the fate of the three men around her. Based on ethical literary criticism, this paper analyzes the entanglement between Lolita and the fate of the three men in her life under the influence of her sphinx factor. Through the free will of the animal factor of the Sphinx factor, Lolita’s fate is tragically interwoven with Humbert and Quilty’s; through the rational will of human factor of sphinx factor, Lolita and Dick’s destinies are intertwined. The different components of the Sphinx factor affect Lolita’s fate. The existence of the animal factor leads to her tragic fate, but the human factor ultimately overcomes the animal factor and achieves the soul’s self-redemption

Pulse shape design for ultra wide band communications

Ultra Wideband (UWB) technology is promising for high-speed short-range communication applications due to its large bandwidth, high data rate, low power requirement and short-range characteristics. Instead of exploring new unused frequency band, the UWB communication follows the overlay principle. The great potential of UWB lies in the fact that it can co-exist with the already licensed spectrum users and can still pave the way for a wide range of applications. Pulse shape design is a key technique in the UWB system. This thesis concentrates on pulse shaping techniques for UWB communication system. -- This thesis first summarizes the main pulse shaping schemes, and then describes the design of a pulse shaping method based on combining Gaussian derivative pulses for impulse based UWB systems. New pulse shapes are created to satisfy the Federal Communications Commission (FCC) spectral mask by this method. Since the objective function of the received signal-to-noise ratio (SNR) optimization is affected by different factors, multiple parameters are also designed to try to achieve the best received SNR. The performance of new pulses and other frequently used UWB pulses are compared through theoretical calculations and simulations coded in MATLAB. -- The main contributions of this thesis include the new determined way of combining certain numbers of Gaussian derivative pulses to create a single pulse that not only conforms to the FCC spectral mask, but also effectively exploits the permitted frequency spectrum, as well as the development of an end-to-end UWB signal transmission simulation chain that can use Time Hopping Pulse Position Modulation (TH-PPM) modulation and Time Hopping Binary Phase Shift Keying (TH-BPSK) modulation through an Additive White Gaussian Noise (AWGN) channel and the IEEE 802.15.3a standard channel model. -- Comparisons have been done of the overall performance of the systems using different pulses in various scenarios such as: single link system use AWGN channel and IEEE standard channel and multiuser system using AWGN channel and IEEE standard channel. In order to exploit the temporal diversity of the multi-path IEEE channel to improve performance of the decision process, a perfect RAKE receiver simulation model is used in the simulation chain. The theoretical calculation and simulation results indicate that the proposed pulses outperform other pulses to different extents under different situations. Discussions on the implementation issues of the pulse shaper are also provided in this thesis. -- The work reported here could act as a starting point from which improvements and extensions can be made and incorporated

Effects of fatty acid activation on photosynthetic production of fatty acid-based biofuels in Synechocystis sp. PCC6803

<p>Abstract</p> <p>Background</p> <p>Direct conversion of solar energy and carbon dioxide to drop in fuel molecules in a single biological system can be achieved from fatty acid-based biofuels such as fatty alcohols and alkanes. These molecules have similar properties to fossil fuels but can be produced by photosynthetic cyanobacteria.</p> <p>Results</p> <p><it>Synechocystis </it>sp. PCC6803 mutant strains containing either overexpression or deletion of the <it>slr1609 </it>gene, which encodes an acyl-ACP synthetase (AAS), have been constructed. The complete segregation and deletion in all mutant strains was confirmed by PCR analysis. Blocking fatty acid activation by deleting <it>slr1609 </it>gene in wild-type <it>Synechocystis </it>sp. PCC6803 led to a doubling of the amount of free fatty acids and a decrease of alkane production by up to 90 percent. Overexpression of <it>slr1609 </it>gene in the wild-type <it>Synechocystis </it>sp. PCC6803 had no effect on the production of either free fatty acids or alkanes. Overexpression or deletion of <it>slr1609 </it>gene in the <it>Synechocystis </it>sp. PCC6803 mutant strain with the capability of making fatty alcohols by genetically introducing fatty acyl-CoA reductase respectively enhanced or reduced fatty alcohol production by 60 percent.</p> <p>Conclusions</p> <p>Fatty acid activation functionalized by the <it>slr1609 </it>gene is metabolically crucial for biosynthesis of fatty acid derivatives in <it>Synechocystis </it>sp. PCC6803. It is necessary but not sufficient for efficient production of alkanes. Fatty alcohol production can be significantly improved by the overexpression of <it>slr1609 </it>gene.</p