Thesis advisor: John E. Ebel / Passive teleseismic data were collected with a 17-station broadband seismic array deployed from Vermont to Massachusetts. The purpose of the array was to detect changes in crustal seismic velocity structure related to the regional tectonostratigraphic terranes using receiver functions. Ps conversions from the Moho and mid-crust were observed and a cross-section of the crustal structure beneath the seismic array was produced. The crustal cross-section reveals a synclinal structure related to the Taconic orogeny, a remnant Iapetan oceanic slab, a plausible surface-location of the Red Indian Line, and several terrane boundaries that can be projected from their proposed surface locations into the deeper crust based on crustal-horizon offsets observed in the receiver function data. / Thesis (MS) — Boston College, 2014. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Earth and Environmental Sciences.

<p>The purpose of this thesis is to build and then optimize a simulation environment for the GSM / EDGE / WCDMA receiver in the RF Asics.</p><p>The system generally consists of two blocks: an Agilent Advanced Design System (ADS) controlled system core and Simulation Environment System for Verification and Design (SEVED). The signal is generated by SEVED and directed into the system core, where the receiver under test is located. Signal output of the receiver is then directed back into SEVED for bit error rate calculations. Therefore the performance of the receiver can be evaluated.</p>

The main purpose of a logotype is to harmonize with a company’s business concept and culture. This study is based on the receiver’s attitudes about three different logotypes - Volvo, Telia and Mcdonald's. It informs the reader about the importance of a logotype as a mean of communication and if the perceptions of the logotype harmonize with the profile of the company. The study also discusses whether the visual aspects of a logotype make any difference in this process. This is a qualitative study that has been conducted through interviews and the purpose is to collect and analyze the receiver’s attitudes regarding the logotypes. The theories of this study are based on visual communication, interpretation and semiotics. Our study shows that the receiver’s attitudes against the logotypes are mostly negative, mainly because the receiver’s were unable to understand the meaning of the logotypes. This study also shows that the receiver’s interpretation of the logotypes depended on a specific context and prejudice.

The ease with which indoor wireless systems can be installed has become their main selling feature. A desirable application for wireless systems is the transmission of compressed digital music in an indoor shopping mall environment. The indoor environment, with its many walls and highly reflective surfaces, has a high level of multipath. High levels of slowly changing multipath can cause deep fades, and therefore reduce the reliability of the system. <p> The proper use of multiple receiving elements is one way to mitigate the deep fades caused by multipath. The main objective of this thesis is to study a simple and cost effective approach to combining the signals from several receiving elements. A novel diversity combining approach using 2 receiving elements is presented. The novel diversity combining approach consists of periodically changing the phase of one of the two received signals. <p> A set of simulations was developed to study the effectiveness of the novel diversity combining method in mitigating deep multipath fades. The relative performances of two different implementations of the diversity combining were compared to a baseline test case that did not include diversity combining. In both of the simulated implementations, the diversity combining approach proved to be an effective means of mitigating the multipath fading phenomenon. <p> A proof-of-concept, bench-top hardware prototype was also developed. The transmitter and receiver were implemented in Field Programmable Gate Arrays (FPGAs). The laboratory testing of the hardware successfully illustrated the feasibility of the proof-of-concept system.

The ease with which indoor wireless systems can be installed has become their main selling feature. A desirable application for wireless systems is the transmission of compressed digital music in an indoor shopping mall environment. The indoor environment, with its many walls and highly reflective surfaces, has a high level of multipath. High levels of slowly changing multipath can cause deep fades, and therefore reduce the reliability of the system. <p> The proper use of multiple receiving elements is one way to mitigate the deep fades caused by multipath. The main objective of this thesis is to study a simple and cost effective approach to combining the signals from several receiving elements. A novel diversity combining approach using 2 receiving elements is presented. The novel diversity combining approach consists of periodically changing the phase of one of the two received signals. <p> A set of simulations was developed to study the effectiveness of the novel diversity combining method in mitigating deep multipath fades. The relative performances of two different implementations of the diversity combining were compared to a baseline test case that did not include diversity combining. In both of the simulated implementations, the diversity combining approach proved to be an effective means of mitigating the multipath fading phenomenon. <p> A proof-of-concept, bench-top hardware prototype was also developed. The transmitter and receiver were implemented in Field Programmable Gate Arrays (FPGAs). The laboratory testing of the hardware successfully illustrated the feasibility of the proof-of-concept system.

The purpose of this thesis is to build and then optimize a simulation environment for the GSM / EDGE / WCDMA receiver in the RF Asics. The system generally consists of two blocks: an Agilent Advanced Design System (ADS) controlled system core and Simulation Environment System for Verification and Design (SEVED). The signal is generated by SEVED and directed into the system core, where the receiver under test is located. Signal output of the receiver is then directed back into SEVED for bit error rate calculations. Therefore the performance of the receiver can be evaluated.

We propose and analyze new finger assignment/management techniques that are applicable for RAKE receivers when they operate in the soft handover region. Two main criteria are considered: minimum use of additional network resources and minimum call drops. For the schemes minimizing the use of network resources, basic principles are to use the network resources only if necessary while minimum call drop schemes rely on balancing or distributing the signal strength/paths among as many base stations as possible. The analyses of these schemes require us to consider joint microscopic/macroscopic diversity techniques which have seldom been considered before and as such, we tackle the statistics of several correlated generalized selection combining output signal-to-noise ratios in order to obtain closed-form expressions for the statistics of interest. To provide a general comprehensive framework for the assessment of the proposed schemes, we investigate not only the complexity in terms of the average number of required path estimations/comparisons, the average number of combined paths, and the soft handover overhead but also the error performance of the proposed schemes over independent and identically distributed fading channels. We also examine via computer simulations the effect of path unbalance/correlation as well as outdated/imperfect channel estimations. We show through numerical exam ples that the proposed schemes which are designed for the minimum use of network resources can save a certain amount of complexity load and soft handover overhead with a very slight performance loss compared to the conventional generalized selection combining-based diversity systems. For the minimum call drop schemes, by accurately quantifying the average error rate, we show that in comparison to the conventional schemes, the proposed distributed schemes offer the better error performance when there is a considerable chance of loosing the signals from one of the active base stations.

No description available.

In this thesis, we take an application of multiple symbol differential detection (MSDD) technique in direct-sequence code division multiple access (CDMA) system. It is well- known that MSDD is an effective noncoherent demodulator which outperform the conventional M-ary differential phase shift keying (MDPSK) in additive white Gaussian noise (AWGN) channel. Take MPSK demodulator into consideration, the performance of MSDD based on noncoherent demodulation approaches the performance of coherent demodulation. However, there is little research about MSDD in frequency-selective fading channel. We are now combining the MSDD and Rake receiver to be the signal demodulator. In conventional, there are two kinds of Rake receivers. One is coherent demodulator. Another is noncoherent demodulator. For coherent demodulation, it needs to have channel estimation at each path. The advantage is that the performance will be improved. On the other hand, the disadvantage is complexity and operation will increase. On the contrast, for noncoherent demodulation, it is the performance degradation and complexity simplification. In this thesis, We suggest a multiple symbol differential detection on Rake receiver for CDMA system. From our computer simulation, only for hard decision, the performance is improved and the improvement is proportional to the number of multipath and the number of the length of multiple symbol. This will not happen in conventional MDPSK. However, from our observation, the improvement of performance is degrading as the number of multipath increase. Thus, we employee the technique of Viterbi decoding differential detection (VDDD) to demodulate the differential sequence. By the property of decision interval, the VDDD can obtain additional improvement.

The circadian input kinase gene (cikA) was first identified from a Tn5 mutant of Synechococcus elongatus PCC 7942. A cikA null strain shows a striking phenotype related to circadian gene regulation: all sampled loci show a shortened circadian period and reduced amplitude of oscillation and a failure to exhibit a wild-type resetting of the phase of the rhythm after an environmental signal. This global defect in response to the environment suggests a key role for CikA in the circadian input pathways. Bioinformatics results classify CikA as a divergent member of the bacteriophytochrome family, suggesting a role in light signal transduction. In vitro analysis previously showed that CikA is a bona fide histidine protein kinase (HPK), and its kinase activity is regulated by the presence of other domains. Its own pseudo-receiver (PsR) domain is not the cognate receiver domain of its kinase HPK domain, and its GAF domain does not likely bind a bilin chromophore as do photoreceptive phytochromes. Recent results suggested that CikA may function as a redox-sensor. In this study, we examined the function of each domain of CikA using different mutant cikA alleles, and determined their phenotypes with respect to complementation of a null mutant and overexpression in both wild type and cikA null strains. All domains except the featureless N-terminus were required for CikA function. Overexpression of all mutant alleles that encoded the PsR domain, whether or not the HPK was functional, caused a dominant arrhythmia phenotype. In the absence of PsR, overexpressed variants did not cause arrhythmia, but affected the amplitude and period of oscillation. The results suggest a model in which the PsR domain regulates kinase activity and mediates interaction with other input pathway components to allow CikA to reach the correct cellular position to fulfill its function. Cellular localization assays showed CikA can interact with a complex and showed a polar localization pattern, whereas its variant without PsR showed uniform distribution in the cell. In summary, CikA is an autoregulated kinase in which the PsR domain regulates activity of the HPK domain and also serves as an interaction module to lead the CikA to a specific cellular position.