UWB has the huge potential to impact the present communication systems due to its enormous available bandwidth, range/data rate trade-off, and potential for very low cost operation. According to FCC, Ultra Wideband (UWB) radio signal defined as a signal that occupies a bandwidth of 500 MHz or fractional bandwidth larger than 20% with strict limits on its power spectral density to -41.3dBm/MHz in the range 3.1GHz to 10.6GHz. Decades of research in the area of wide-band systems have lead us to new possibilities in the design of low power, low complexity radios, comparing with existing narrowband radio systems. In particular, impulse radio based ultra wideband (IR-UWB) is a promising solution for short-range radio communications such as low power radio-frequency identification (RFID), wireless sensor network's and wireless personal area network (WPAN) etc. Since a simple circuit, architecture adopted in the IR-UWB system, the non-idealities of receiver front end may lead to degrade the overall performance. Therefore, it is important to study these effects in order to create robust and efficient UWB system. However, majorities of recent studies are formed on the channel analysis, rather than the receiver system. The main objectives of this thesis work are, (a) System level modeling of non-coherent IR-UWB receiver, (b) Performance analysis of IR-UWB receiver with the help of bit error rate (BER) estimation, (c) A study on the impact of receiver front end non-idealities over BER, (d) Analysis of charge leakage in integrator and its effect on overall performance of UWB receiver. In this work, IR-UWB non-coherent energy detector receiver operating in the frequency band of 3GHz-5GHz based on the on-off keying (OOK) modulation was simulated in Matlab/Simulink. The effect of receiver front end non idealities and integrator charge leakages were discussed in detail with respect to overall performance of the receiver. The results show that non idealities and leakage degrade the performance as expected. In order to achieve a specific BER of 10-2 with the integrator leakage of 25%, the SNR should be increased by 2.1 dB compared to the SNR with no leakage at a data rate of 200Mbps. Finally, integrator design and its specifications were discussed.

A high-throughput low-power Soft-Output Viterbi decoder designed for the convolutional codes used in the ECMA-368 UWB standard is presented in this thesis. The ultra wide band (UWB) wireless communication technology is supposed to be used in physical layer of the wireless personal area network (WPAN) and next generation Blue Tooth. MB-OFDM is a very popular scheme to implement the UWB system and is adopted as the ECMA-368 standard. To make the high speed data transferred over the channel reappear reliably at the receiver, the error correcting codes (ECC) are wildly utilized in modern communication systems. The ECMA-368 standard uses concatenated convolutional codes and Reed-Solomon (RS) codes to encode the PLCP header and only convolutional codes to encode the PPDU Payload. The Viterbi algorithm (VA) is a popular method of decoding convolutional codes for its fairly low hardware implementation complexity and relatively good performance. Soft-Output Viterbi Algorithm (SOVA) proposed by J. Hagenauer in 1989 is a modified Viterbi Algorithm. A SOVA decoder can not only take in soft quantized samples but also provide soft outputs by estimating the reliability of the individual symbol decisions. These reliabilities can be provided to the subsequent decoder to improve the decoding performance of the concatenated decoder. The SOVA decoder is designed to decode the convolutional codes defined in the ECMA-368 standard. Its code rate and constraint length is R=1/3 and K=7 respectively. Additional code rates derived from the "mother" rate R=1/3 codes by employing "puncturing", including 1/2, 3/4, 5/8, can also be decoded. To speed up the add-compare-select unit (ACSU), which is always the speed bottleneck of the decoder, the modified CSA structure proposed by E.Yeo is adopted to replace the conventional ACS structure. Besides, the seven-level quantization instead of the traditional eight-level quantization is proposed to be used is in this decoder to speed up the ACSU in further and reduce its hardware implementation overhead. In the SOVA decoder, the delay line storing the path metric difference of every state contains the major portion of the overall required memory. A novel hybrid survivor path management architecture using the modified trace-forward method is proposed. It can reduce the overall required memory and achieve high throughput without consuming much power. In this thesis, we also give the way to optimize the other modules of the SOVA decoder. For example, the first K-1 necessary stages in the Path Comparison Unit (PCU) and Reliability Measurement Unit (RMU) are IX removed without affecting the decoding results. The attractiveness of SOVA decoder enables us to find a way to deliver its soft output to the RS decoder. We have to convert bit reliability into symbol reliability because the soft output of SOVA decoder is the bit-oriented while the reliability per byte is required by the RS decoder. But no optimum transformation strategy exists because the SOVA output is correlated. This thesis compare two kinds of the sub-optimum transformation strategy and proposes an easy to implement scheme to concatenate the SOVA decoder and RS decoder under various kinds of convolutional code rates. Simulation results show that, using this scheme, the concatenated SOVA-RS decoder can achieve about 0.35dB decoding performance gain compared to the conventional Viterbi-RS decoder.

Ultra Wide Band (UWB) is a new spectrum allocation which was recently approved by the Federal Communication Commission (FCC) and is under study in Europe and Asia. It has emerged as a solution to provide low complexity, low cost, low power consumption, and high-data-rate wireless connectivity devices entering the personal space. Any wireless system that has a fractional bandwidth greater than 20% and a total bandwidth larger than 500MHz enters in the UWB definition. At the emission level, UWB signals have a mask that limits its spectral power density to -41.3dBM/MHz between 3.1Ghz and 10.6GHz. There are two approaches that have been studied in order to use the 7.5Ghz allocated for UWB systems. First, OFDM techniques can be used to cover the entire spectrum; these techniques are called multi-band UWB. On the other hand, the second approach makes use of impulse radios which generate very-short-duration baseband pulses that occupy the whole spectrum. The objective of this thesis is to study, design, prototype, and test a UWB impulse radio using off-chip components. A Direct Sequence (DS) UWB transceiver architecture was selected. The transmitter uses first derivative Gaussian pulses that are modulated using a bi-phase modulation technique. The pulse rate of the system is 100MHz and the bit rates under investigation were 100Mbps, 50Mbps, 25Mbps, and 10Mbps. The transmitter and receiver were divided in functional blocks in order to execute system level simulations. The transmitter was implemented in both schematics and layout, and the UWB pulse generator block was constructed and tested in order to validate its functionality. On the other hand, the off-chip implementation of the receiver presented particular difficulties that made its construction not possible in this study. As a result, the blocks of the receiver were implemented in Matlab and the performance of the whole transceiver was estimated through numeric simulations. Finally, a case study for the multi-user capability of the system was presented.

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This thesis work consists of two different research projects. In the first project the optimization of the Frequency Shifted Reference-Ultrawideband (FSR-UWB) is discussed. After identifying the improvement areas in the FSR-UWB scheme, we performed analysis and proposed optimized values of the restricted integration and the front-end filter. It is observed that, by integrating the received signal over the entire symbol period, excess noise is allowed into the system and thus potentially degrades the performance. We showed that by restricting the integration period we get the expected gains in an Additive White Gaussian Noise (AWGN) channel but the gains are limited for a multipath fading channel. For these limited gains, the new integration block unnecessarily complicates the receiver structure. For front-end filter optimization the system performance is analyzed using a generic filter, h(t) and it is shown that a matched filter is the optimal filter for low values of Es/N0 whereas a unity gain band pass filter is optimal for high Es/N0 values, where Es is the symbol energy and N0/2 is the power spectral density of additive white Gaussian noise. In the second project we explored a general class of waveforms that can be used as separating waveforms to provide multiple-access for FSR-UWB systems. It is shown in this section that for single user scenario binary codes selected from {−1, 1} are optimal codes that can be used to separate data and the reference signals. For multiple-user access, a class of polynomials are discussed that can be used as separating waveform as they completely eliminate MAI. It is shown in the latter part that the optimal codes for multiple-user access are the binary codes selected from {−1, 1}. These codes are selected as the row vectors of the Hadamard Matrix. Simulation supported the application of this analysis to UWB systems, with either a small number of frames or operating over channels with small delay spread.

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<p>The first flexible chip-less RFID temperature sensor system for food monitoring to have a  resolution of 0.2  <strong>°</strong>C for temperature measurements between 79  <strong>°</strong>C and -22.8  <strong>°</strong>C is introduced. This  system has a significant improvement in temperature range compared to current flexible RFID  sensors and can provide high accuracy measurements for real time food monitoring at the system  level. Flexible sensors provide low-cost, better flexibility, and longer service life; hence, flexible  sensor systems can provide a new future for food monitoring in commercial applications. The  proposed system presents a new feature and enables a food monitoring system that utilizes a  flexible sensor system. The system introduced in this paper enables a wireless measurement system  providing 100 dB dynamic range with 160 Msps and 16-bit resolution for precise temperature  measurements that are critical for food quality within 100  <strong>°</strong>C temperature range. The full sensing  system is designed, tested and measurements results are confirmed to be within expected accuracy </p>

This thesis explores the possibility of using ultra wideband technology to localize anoutdoor mobile robot. More explicitly, this project focuses on the multilaterationproblem where the topology of the static reference anchors are changed. Insteadof having stationary anchors they are placed on a mobile robot and by pinpointingone single static tag node the position of the robot is established. The research usesa robotic lawn mover from Husqvarna, the Automover 430X. The robot is used asa base platform for this thesis to evaluate if this approach is applicable for othergeneric robots in the same size. The feasibility of this solution is demonstratedthrough simulation using Matlab and the robot simulation environment Gazebo.Results show that this specific topology is feasible for tracking a specific point butis also suitable for positioning a mobile robot if coupled with an accurate headingsensor. The system was evaluated for several scenarios of which all indicated anadequate accuracy, provided that data from an encoder was used. The upper limitfor the position error in a one sided 95% confidence interval was 0.469m at a rangeof 40m. / Detta examensarbete tar sig an problemet att lokalisera en långsamtgående mobilrobot i en utomhusmiljö genom att använda sig av ultra wideband radioteknik. Vanligtvisplaceras stationära noder i miljön som används för att positionera en ensamnod i dess närhet. Detta projekt tar sig an frågeställningen om det är möjligt attvända på problemet och placera dessa stationära noder på den mobila roboten föratt sedan fixera robotens position genom att bestämma vart den ensamma nodenär placerad. Husqvarnas robotgräsklippare Automover 430X har används som plattformför att evaluera och testa om denna tes är applicerbar för andra generiska robotari samma storlek. Positionsuppskattningen utförs genom simulationer i Matlabsamt simulationsmiljön Gazebo som tar hänsyn till diverse fysiska fenomen. Resultatenpekar på att denna topologi är möjlig för att lösa multilatereringsproblemetom en riktningssensor med hög precision används. För alla scenarion som simuleradesindikerades att en någorlunda god precision kan uppnås och det krävdes attsystemet kombinerades med annan indata, som en enkoder i detta fall för att förbättraestimeringen. Den övre gränsen för felet i ett 95% konfidensintervall var 0.469mpå ett avstånd upp till 40m.

Ultra-wide Band (UWB) has sparked a lot of interest lately from the industry and academia. The growing capacity of the wireless industry is requires a new communication system that satisfies the high data rate which does not interfere with existing RF systems. UWB promises to be this new technology. UWB also promises low power, low cost and flexibility. The UWB Channel opens up a huge new wireless channel with Giga Hertz Capacities as well as the highest spatial capacities measured in bits per hertz per square meter. When properly implemented UWB channel can share spectrum with traditional radio systems without causing harmful interference. In this thesis we studied and compared several reduced complexity sub-optimal Ultra-Wide Band receivers. These receivers include auto correlation receiver, the square value detector and the absolute value detector are studied. We consider OOK and PPM modulation schemes. We examine these schemes and the receivers on Gaussian and UWB indoor channels. We compare the performance with optimal receivers. A transmitter receiver system using 0.1us pulses implemented using existing hardware. A packet consisting of 24 bits were transmitted and the received signal could be verified in real time using a vector signal analyzer. The results show sub-optimal receivers provide a better trade off between robust, complexity and performance.