The ever-growing demand for higher quality and faster multimedia content delivery over short distances in home environments drives the quest for higher data rates in wireless personal area networks (WPANs). One of the candidate IEEE 802.15.3a WPAN proposals support data rates up to 480 Mbps by using punctured convolutional codes with quadrature phase shift keying (QPSK) modulation for a multi-band orthogonal frequency-division multiplexing (MB-OFDM) system over ultra wideband (UWB) channels. In the first part of this dissertation, we combine more powerful near-Shannon-limit turbo codes with bandwidth efficient trellis coded modulation, i.e., turbo trellis coded modulation (TTCM), to further improve the data rates up to 1.2 Gbps. A modified iterative decoder for this TTCM coded MB-OFDM system is proposed and its bit error rate performance under various impulsive noises over both Gaussian and UWB channel is extensively investigated, especially in mismatched scenarios. A robust decoder which is immune to noise mismatch is provided based on comparison of impulsive noises in time domain and frequency domain. The accurate estimation of the dynamic noise model could be very difficult or impossible at the receiver, thus a significant performance degradation may occur due to noise mismatch. In the second part of this dissertation, we prove that the minimax decoder in \cite, which instead of minimizing the average bit error probability aims at minimizing the worst bit error probability, is optimal and robust to certain noise model with unknown prior probabilities in two and higher dimensions. Besides turbo codes, another kind of error correcting codes which approach the Shannon capacity is low-density parity-check (LDPC) codes. In the last part of this dissertation, we extend the density evolution method for sum-product decoding using mismatched noises. We will prove that as long as the true noise type and the estimated noise type used in the decoder are both binary-input memoryless output symmetric channels, the output from mismatched log-likelihood ratio (LLR) computation is also symmetric. We will show the Shannon capacity can be evaluated for mismatched LLR computation and it can be reduced if the mismatched LLR computation is not an one-to-one mapping function. We will derive the Shannon capacity, threshold and stable condition of LDPC codes for mismatched BIAWGN and BIL noise types. The results show that the noise variance estimation errors will not affect the Shannon capacity and stable condition, but the errors do reduce the threshold. The mismatch in noise type will only reduce Shannon capacity when LLR computation is based on BIL.

No / A novel miniaturized planar inverted F-L antenna assembly is considered for UWB radio operations. The antenna design utilizes the electromagnetic coupling between an air dielectric planar inverted-F antenna (PIFA) and a parasitic planar inverted-L (PIL) element, with broadband feeding from a rectangular plate. To improve the functionality of the channel, a simple notch filter has been introduced through a local modification to the broadband feed plate, this takes the form of a simple slotted rectangular spiral resonator which is etched directly onto the plate. This allows the proposed antenna to maintain its full band UWB coverage, with the HYPERLAN/2 band centered at 5.35 GHz to be effectively rejected over the sub-band 5.15–5.725 GHz, without the need for substantial re-optimization of its principal structure parameters. The impedance bandwidth operates over the full UWB band, with VSWR better than 2, this performance is not degraded by the presence of the band rejection. The observed gains, radiation patterns, and group delay confirm that the antenna has appropriate characteristics for short range wireless applications.

No / A miniaturized modified planar inverted-F antenna (PIFA) is presented and experimentally studied. This antenna consists of a planar rectangular monopole top-loaded with a rectangular patch attached to two rectangular plates, one shorted to the ground and the other suspended, both placed at the optimum distance on each side of the planar monopole. The fabricated antenna prototype had a measured impedance bandwidth of 125%, covering 3 to 13GHz for reflection coefficient better than -10 dB. The radiator size was 20 x 10 x 7.5 mm(3), making it electrically small over most of the band and suitable for incorporation in mobile devices. The radiation patterns and gains of this antenna have been cross-validated numerically and experimentally and confirm that this antenna has adequate characteristics for short range ultra-wideband wireless applications.

No / This study presents a miniaturised multiple input and multiple output /diversity antenna which is suitable for high data-rate communication systems such as mobile ultra-wideband (UWB). This antenna assembly comprises two identical planar inverted-F antennas, a T-shaped structure connecting them and a finite ground plane. The T-shaped structure improves the impedance matching and suppresses the mutual coupling between the antenna elements over a wider bandwidth than previously reported. The compact envelope dimension of this antenna is 50 x 90 x 7.5 mm(3). Theoretical and experimental S-parameters are illustrated for this antenna that fully cover the UWB operating frequency band of 3.1-10.6 GHz, with a reflection coefficient and mutual coupling better than -10 and -20 dB, respectively. Acceptable agreement is obtained between computed and measured radiation patterns, gains, envelope correlation coefficient and channel capacity loss. The proposed antenna is an attractive candidate to provide pattern diversity and enhance channel capacity in a rich scattering environment.

Sjöfartshögskolan i Kalmar har ett långtgående studentprojekt att bygga en modell av skolfartyget M/S Calmare Nyckel som autonomt ska köra runt i en damm på skolan för att visa upp skolans profil. Projektet är tänkt att sammanfoga kunskaper från många olika delar av utbildningen såsom elektronik, programmering, och stabilitet. Detta arbete syftar till att undersöka Ultra Wideband som teknik för positionering av modellen för att i framtiden kunna använda positionen för att navigera i dammen. Specifikt så användes tre chip av typen ESP32 UWB som implementation av Ultra Wideband då det var ett billigt alternativ som verkade lovande. Två av chippen var stillastående på kända positioner och positionen för det tredje chippet räknas ut med hjälp av triangulering. Den uppmätta noggrannheten för systemet anses inte vara tillräckligt bra för att fortsätta med ESP32 UWB i fortsättningen av projektet.En båtmodell av M/S Calmare Nyckel togs fram med hjälp av CAD programmet Autodesk Fusion 360 och tanken är att båtmodellen ska 3D printas på universitetet och sedan byggas ut med RC komponenter så båtmodellen kan göra fart genom vatten. Tanken är även att båtmodellen ska kunna manövrera helt autonomt till en laddstation för att sedan återvända ut på sin planerade rutt. Med hjälp av forum och experter online så har alternativ till vilka typer av komponenter såsom, elmotor, styrservo, propeller och annat som behövs för driften tagits fram. Alternativen är bara förslag på vilka komponenter som rekommenderas och inga exakta modeller. / The Kalmar Maritime Academy have an ongoing student project to build a model of the academy’s training ship M/S Calmare Nyckel. The model is supposed to autonomously sail around a pond located in the academy’s premises to show off the academy’s profile. The project is intended to combine knowledge from many different parts of the program such as electronics, programming, and stability. This project aims to investigate Ultra Wideband as a technology for positioning the model to be able to use the position to navigate the pond. Three ESP32 UWB chips were used as an implementation of Ultra Wideband as it was a cheap alternative that showed promise. Two of the chips were stationary at known positions and the position of the third chip is then calculated using triangulation. The measured accuracy of the system is not considered good enough to continue with the ESP32 UWB in the continuation of the project.A boat model of M/S Calmare Nyckel was produced using the CAD program Autodesk Fusion 360 and the idea is that the boat model can be 3D printed at the university and then expanded with RC components so that the boat model can make speed through water. The idea is also that the boat model should be able to maneuver completely autonomously to a charging station and then return to its planned route. With the help of online forums and experts, alternatives to the types of components such as electric motor, steering servo, propeller, and other things needed for operation have been developed. The options are only suggestions of which components are recommended and not exact models.

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As Orthogonal Frequency Division Multiplexing (OFDM) becomes more prevalent in new leading-edge data rate systems processing spectral bandwidths beyond 1 GHz, the required operating speed of the baseband signal processing, specifically the Analog- to-Digital Converter (ADC) and Fast Fourier Transform (FFT) processor, presents significant circuit design challenges and consumes considerable power. Additionally, since Ultra-WideBand (UWB) systems operate in an increasingly crowded wireless environment at low power levels, the ability to tolerate large blocking signals is critical. The goals of this work are to reduce the disproportionately high power consumption found in UWB OFDM receivers while increasing the receiver linearity to better handle blockers. To achieve these goals, an alternate receiver architecture utilizing a new FFT processor is proposed. The new architecture reduces the volume of information passed through the ADC by moving the FFT processor from the digital signal processing (DSP) domain to the discrete time signal processing domain. Doing so offers a reduction in the required ADC bit resolution and increases the overall dynamic range of the UWB OFDM receiver. To explore design trade-offs for the new discrete time (DT) FFT processor, system simulations based on behavioral models of the key functions required for the processor are presented. A new behavioral model of the linear transconductor is introduced to better capture non-idealities and mismatches. The non-idealities of the linear transconductor, the largest contributor of distortion in the processor, are individually varied to determine their sensitivity upon the overall dynamic range of the DT FFT processor. Using these behavioral models, the proposed architecture is validated and guidelines for the circuit design of individual signal processing functions are presented. These results indicate that the DT FFT does not require a high degree of linearity from the linear transconductors or other signal processing functions used in its design. Based on the results of the system simulations, a prototype 8-point DT FFT processor is designed in 130 nm CMOS. The circuit design and layout of each of the circuit functions; serial-to-parallel converter, FFT signal flow graph, and clock generation circuitry is presented. Subsequently, measured results from the first proof-of-concept IC are presented. The measured results show that the architecture performs the FFT required for OFDM demodulation with increased linearity, dynamic range and blocker handling capability while simultaneously reducing overall receiver power consumption. The results demonstrate a dynamic range of 49 dB versus 36 dB for the equivalent all-digital signal processing approach. This improvement in dynamic range increases receiver performance by allowing detection of weak sub-channels attenuated by multipath. The measurements also demonstrate that the processor rejects large narrow-band blockers, while maintaining greater than 40 dB of dynamic range. The processor enables a 10x reduction in power consumption compared to the equivalent all digital processor, as it consumes only 25 mWatts and reduces the required ADC bit depth by four bits, enabling application in hand-held devices. Following the success of the first proof-of-concept IC, a second prototype is designed to incorporate additional functionality and further demonstrate the concept. The second proof-of-concept contains an improved version of the serial-to-parallel converter and clock generation circuitry with the additional function of an equalizer and parallel- to-serial converter. Based on the success of system level behavioral simulations, and improved power consumption and dynamic range measurements from the proof-of-concept IC, this work represents a contribution in the architectural development and circuit design of UWB OFDM receivers. Furthermore, because this work demonstrates the feasibility of discrete time signal processing techniques at 1 GSps, it serves as a foundation that can be used for reducing power consumption and improving performance in a variety of future RF/mixed-signal systems. / Ph. D.

Generation of high-peak power, microwave ultra-short pulses (USPs) is desirable for ultra-wideband communications and remote sensing. A variety of microwave USP generators exist today, or are described in the literature, and have benefits and limitations depending on application. A new class of pulse compressors for generating USPs using electromagnetic time reversal (TR) techniques have been developed in the last decade, and are the topic of this dissertation. This dissertation presents a compact TR microwave pulse-compression cavity that has ultra-wide bandwidth (5 GHz – 18 GHz), and employs waveguide feeds for high-peak power output over the entire band. The system uses a time-reversal-based pulse compression scheme with one-bit processing (OBTR) to achieve high compression gain. Results from full-wave simulations are presented as well as measurements showing compression gain exceeding 21.2 dB, 22% efficiency, and measured instantaneous peak output powers reaching 39.2 kW. These are all record results for this type of pulse compressor. Additionally presented is new analysis of variation in compression gain due to impulse response recording time and bandwidth variation, new experimental work on the effect of mode stirrer position on compression gain, and a novel RF switch-based technique for reducing time-sidelobes while using OBTR. Finally, a new technique is presented that uses a reverberant cavity with only one feed connected to an ultra-wideband circulator (6.5 GHz to 17 GHz) to perform TRPC. Prior to this work, TRPC has only been demonstrated in electromagnetics using two or more feeds and a reverberant cavity acting as the time-reversal mirror. This new 1-port technique is demonstrated in both simulation and measurement. The proposed system achieves up to a measured 3 dB increase in compression gain and increased efficiency. Also, a novel application of the random coupling model (RCM) to calculate compression gain is presented. The cavity eigenfrequencies are modeled after eigenvalues of random matrices satisfying the Gaussian orthogonal ensembles (GOE) condition. Cavity transfer functions are generated using Monte Carlo simulations, and used to compute the compression gains for many different cavity realizations. / Doctor of Philosophy / Generation of high-peak power, microwave ultra-short pulses (USPs) is desirable for ultra-wideband communications and remote sensing. A variety of microwave USP generators exist today, or are described in the literature, and have benefits and limitations depending on application. A new class of pulse compressors for generating USPs using electromagnetic time reversal (TR) techniques have been developed in the last decade, and are the topic of this dissertation. This dissertation presents a compact TR-based microwave pulse-compression cavity that has unique features that make it optimal for high-power operations, with results from simulations as well as measurements showing improved performance over other similar cavities published in the literature with a record demonstrated peak output power of 39.2 kW. Additionally, new analysis on the operation and optimization of this cavity for increased performance is also presented. Finally, a new technique is presented that uses a cavity with only one feed that acts as both the input and output. This 1-port technique is demonstrated in both simulation and measurement. The proposed system achieves a two-times increase in compression gain over its 2-port counterpart. In conjunction with these measurements and simulations, a novel technique for predicting the performance of these cavities using Monte Carlo simulation is also presented.