Time Delay of Arrival (TDOA) based algorithms and Steered Response Power (SRP) based algorithms are two most commonly used methods for sound source detection and localization. SRP is more robust under high reverberation and multi-target conditions, while TDOA is less computationally intensive. This thesis introduces a modified TDOA algorithm, TDOA delay table search (TDOA-DTS), that has more stable performance than the original TDOA, and requires only 4% of the SRP computation load for a 3-dimensional space of a typical room. A 2-step adaptive thresholding procedure based on a Weibull noise peak distributions for the cross-correlations and a binomial distribution for combing potential peaks over all microphone pairs for the final detection. The first threshold limits the potential target peaks in the microphone pair cross-correlations with a user-defined false-alarm (FA) rates. The initial false-positive peak rate can be set to a higher level than desired for the final FA target rate so that high accuracy is not required of the probability distribution model (where model errors do not impact FA rates as they work for threshold set deep into the tail of the curve). The final FA rate can be lowered to the actual desired value using an M out of N (MON) rule on significant correlation peaks from different microphone pairs associated is a point in the space of interest. The algorithm is tested with simulated and real recorded data to verify resulting FA rates are consistent with the user-defined rates down to 10-6.

The necessity of interconnecting objects more and more, possibly with high mobility, has pushed the telecommunications industry to recently develop new wireless standards in order to guarantee tracking of devices and to provide integration with well-known worldwide networks such as the Internet. Within these standards the role played by power consumption is implicit, hence power consumption needs to be as low as possible in order to fulfill long-life requirements and to offer the opportunity of locating and moving smart objects in the coverage area while relying only on batteries as the device's power source.  Considering the importance of identifying and tracking these smart objects with high accuracy and high precision, this document propose an implementation of an IEEE 802.15.4a MAC layer, exploiting ultra-wideband wireless technology, with a time synchronization algorithm included for precise Time Difference of Arrival indoor positioning. Nevertheless, this thesis demonstrates the advantages of using UWB for indoor wireless communication, due to its accuracy in localization and its robustness against interference. A demonstration network has been analyzed consisting of four main base stations optimistically displaced at the corners of a room gathering timestamps from a central tag moving within the space where the UWB signal is within range. These timestamps are collected in one of the base station which plays the role of the coordinator and sends this information to a server which computes the position of the tag using TDOA formulation. The main focus of this work is the synchronization algorithms used to synchronize the four base stations and secondly to synchronize the coordinator with the tag. Particular interest is placed on the protocol, the kind of messages exchanged, and the procedure used to maintain a good level of synchronization and to avoid unwanted clock drifts. Moreover the thesis gives some hints of potential future improvements and proposes a possible solution for large-scale scenarios involving the installation of additional base stations for higher coverage and integration of a larger number of tags, with a focus on synchronization, collision avoidance, and routing procedures to better Fit the situation of a larger network and more tags.  As a result, all the assumptions and the methodologies applied give evidence of how difficult it is to meet contemporary requirements for position accuracy, low power consumption, limited memory, and small message exchange when utilizing low-power and lossy networks and to address problems which need to be further studied in the future. The results of this thesis project offer a good proof of the possibility to reach high accuracy in terms of localization when exploiting UWB radio technology and redundant time synchronization algorithms with the help of TDOA measurements. / Nödvändigheten av sammankopplade objekt mer och mer, eventuellt med hög rörlighet, har drivit telekombranschen till nyligen utveckla nya tråadlösa standarder för att garantera spåarning av enheter och att ge integration med välkända världsomspännande nätverk som Internet. Inom dessa standarder roll strömförbrukningen är implicit, måaste därför strömförbrukningen ska vara såa låag som möjligt för att uppfylla låang livslängd krav och erbjuda möjligheten att lokalisera och flytta smarta objekt i täckningsområadet medan enbart med hjälp av batterier som enhetens strömkälla. Med tanke påa vikten av att identiera och spåara dessa smarta objekt med hög noggrannhet och hög precision, detta dokument föreslåa ett genomförande av en IEEE 802.15.4a MAC-lager, utnyttja ultrabredbandsteknik tråadlös teknik, med en tidssynkronisering algoritm ingåar för exakt tidsskillnaden för ankomst inomhus positionering. Ändåa visar denna avhandling fördelarna med att använda UWB för inomhus tråadlös kommunikation, påa grund av dess noggrannhet i lokalisering och robusthet mot störningar. En demonstration nätverk har analyserats beståar av fyra huvudsakliga basstationer optimistiskt förskjutna i hörnen av ett rum samla tidsstämplar fråan en central tagg flyttar inom utrymme där UWB signalen är inom räckhåall.  Dessa tidsangivelser samlas i en av basstationen som spelar rollen av samordnare och skickar denna information till en server som beräknar position taggen med TDOA formulering. Tyngdpunkten i detta arbete är att synkronisering algoritmer som används för att synkronisera de fyra basstationer dels att synkronisera samordnaren med taggen. Särskilt intresse läggs vid protokollet, den typ av utbytta meddelanden och det förfarande som används för att upprätthåalla en god nivåa av synkronisering och för att undvika oönskade klocka drivor. Dessutom avhandlingen ger nåagra tips om potentiella framtida förbättringar och föreslåar en möjlig lösning för storskaliga scenarier som innebär installation av ytterligare basstationer för högre täckning och integration av ett större antal taggar, med fokus påa synkronisering, att undvika kollision och routing förfaranden för att bättre passa situationen i ett större nätverk och fler taggar.  Som ett resultat, som tillämpas alla antaganden och metoder vittnar om hur svåart det är att uppfylla dagens krav påa positionsnoggrannhet, låag strömförbrukning, begränsat minne, och småa utbyte av meddelanden vid användning med låag effekt och förstörande nätverk och att ta itu med problem som måaste studeras vidare i framtiden. Resultaten fråan denna avhandling projekt erbjuder en bra bevis påa möjligheten att nåa hög noggrannhet vad gäller lokalisering vid utnyttjande UWB radioteknik och redundanta tid algoritmer synkronisering med hjälp av TDOA mätningar.

Classically, wide-area synchronized power system monitoring has been an expensive task requiring significant investment in utility communications infrastructures for the service of relatively few costly sensors. The purpose of this research is to demonstrate the viability of power system monitoring from very low voltage levels (120 V). Challenging the accepted norms in power system monitoring, the document will present the use of inexpensive GPS time synchronized sensors in mass numbers at the distribution level. In the past, such low level monitoring has been overlooked due to a perceived imbalance between the required investment and the usefulness of the resulting deluge of information. However, distribution level monitoring offers several advantages over bulk transmission system monitoring. First, practically everyone with access to electricity also has a measurement port into the electric power system. Second, internet access and GPS availability have become pedestrian commodities providing a communications and synchronization infrastructure for the transmission of low-voltage measurements. Third, these ubiquitous measurement points exist in an interconnected fashion irrespective of utility boundaries. This work offers insight into which parameters are meaningful to monitor at the distribution level and provides applications that add unprecedented value to the data extracted from this level. System models comprising the entire Eastern Interconnection are exploited in conjunction with a bounty of distribution level measurement data for the development of wide-area disturbance detection, classification, analysis, and location routines. The main contributions of this work are fivefold: the introduction of a novel power system disturbance detection algorithm; the development of a power system oscillation damping analysis methodology; the development of several parametric and non-parametric power system disturbance location methods, new methods of power system phenomena visualization, and the proposal and mapping of an online power system event reporting scheme. / Ph. D.