Ultra Wideband: Communication and Localization

Sammanfattning: The first part of this thesis develops methods for UWB communication. To meet the stringent regulatory body constraints, the physical layer signaling technique of the UWB transceiver should be optimally designed. We propose two signaling schemes which are variants of pulse position modulation (PPM) signaling for impulse radio (IR) UWB communication. We also discuss the detectors for the signaling schemes and evaluate the performance of these detectors.  IR-UWB can be used for precise range measurements as it provides a very high time resolution. This enables accurate time of arrival (TOA) estimations from which precise range values can be derived. We propose methods which use range information to arrive at optimal schedules for an all-to-all broadcast problem. Results indicate that throughput can be increased on average by three to ten times for typical network configurations compared to the traditional methods. Next, we discuss hypothesis testing in the context of UWB transceivers. We show that, when multiple detector outputs from a hardware platform are available, fusing the results from them can yield better performance in hypothesis testing than relying on a single detector output. In the second part of this thesis, the emphasis is placed on localization and joint estimation of location and communication parameters. Here, we focus on estimating the TOA of the signal. The wide bandwidth of the UWB signal requires high speed analog to digital converts (ADC) which makes the cost of the digital transceivers prohibitively high. To address this problem, we take two different strategies. In the first approach, we propose a multichannel receiver with each channel having a low-cost energy detector operating at a sub-Nyquist rate. In the second approach, we consider a compressive sampling based technique. Here, we propose a new acquisition front end, using which the sampling rate of the ADC can be significantly reduced. We extended the idea of compressive sampling based TOA estimation towards joint estimation of TOA and PPM symbols. Here, two signaling methods along with the algorithms are proposed based on the dynamicity of the target. They provide similar performance to the ML based estimation, however with a significant savings in the ADC resources.