The purpose of this research is to investigate a novel way of combining carrier signals that are transmitted successively over Multiple Frequencies (MF) and traditional metrics to improve AoA estimation. Every signal contains three metrics, amplitude, phase, and frequency. To achieve localisation, current systems utilise the metrics of amplitude (also known as Received Signal Strength (RSS)) and phase that resolves the AoA. However, the metric of frequency is mostly used with Orthogonal Frequency-Division Multiplexing (OFDM) to increase the number of RSS and AoA metrics, which is not optimal. This research answers two questions. Can the use of MF improve AoA estimation? Also, how can MF and traditional metrics be combined for AoA estimation? The aim is to prove that the metric of frequency can be utilised more optimally. Therefore, measurements of RSS and AoA are performed in different environments for MF. To perform these measurements, ten frequency diverse Software Defined Radios (SDRs) are employed. A novel technique to time/frequency synchronise the SDRs is developed and presented. Moreover, a ten element Uniform Linear Array (ULA) is designed, simulated and manufactured. The outcomes of this research are two novel algorithms for the MF AoA estimation of a carrier transmitter. Findings of the first algorithm show that the use of MF with the RSS metric performs equally with current systems that have a higher cost and complexity. The second algorithm that utilises MF with the AoA metric demonstrates a significant reduction in the AoA estimation error, compared to current systems. Specifically, for 50\% of the measured cases the AoA estimation error is reduced by 3.7 degrees, while for 95\% of the measured cases the AoA estimation error is reduced by 27 degrees. Hence, this research proves that MF with traditional metrics can reduce system complexity and greatly improve AoA estimation.

RF 30 GHz ray-tracing simulation results are presented from a conceptual Massive-Multiple Input Multiple Output (M-MIMO) propagation model in an urban canyon. The usage of Constant Envelope (CE) RF signals is evaluated in both propagation ray-rich and ray-sparse scenarios. Multiple mobile terminals are simulated each employing single carrier Phase Shift Keying (PSK). It is found that once an operational link budget is achieved CE transmitters have negligible effect on a received Error Vector Magnitude (EVM). Finally it is found that the EVM is a function of both richness of propagation rays as well as the relative proximities of mobile users. A worst-case EVM of circa 25% is observed when terminals are separated by 1m reducing to circa 5% when terminals are separated by more than 4m.

This paper overviews new and emerging wireless technologies that could positively impact on the lives of the elderly or disabled, as Social Care users of Assistive Technology (AT) for 'independent living'. Novel Internet of Things (IoT) radio systems and wireless locating systems being researched at The University of Sheffield are discussed in the context of Social Care technology usecases.

This paper overviews new and emerging wireless technologies that could positively impact on the lives of the elderly or disabled, as Social Care users of Assistive Technology (AT) for 'independent living'. Novel Internet of Things (IoT) radio systems and wireless locating systems being researched at The University of Sheffield are discussed in the context of Social Care technology use-cases.

This paper introduces a new and affordable method of realising 10 IQ Software Defined receivers, and how to synchronise them. We first discuss the need for multiple IQ and the available techniques. We then introduce the RTL-SDR and Matlab as a very low cost prototype implementation of 10 IQ streams. This leads to the design and manufacture of a PCB to distribute a single clock to multiple RTL-SDRs. The required modifications to the RTL-SDRs to receive the distributed clock and other modifications to improve the overall performance are presented. We then describe how to attain raw IQ data and synchronise the receivers. Finally, we prove all 10 can maintain a phase lock over a frame of 7 seconds.

This paper introduces a new and affordable method of realising 10 IQ Software Defined receivers, and how to synchronise them. We first discuss the need for multiple IQ and the available techniques. We then introduce the RTL-SDR and Matlab as a very low cost prototype implementation of 10 IQ streams. This leads to the design and manufacture of a PCB to distribute a single clock to multiple RTL-SDRs. The required modifications to the RTL-SDRs to receive the distributed clock and other modifications to improve the overall performance are presented. We then describe how to attain raw IQ data and synchronise the receivers. Finally, we prove all 10 can maintain a phase lock over a frame of 7 seconds.

This paper investigates the performance of high rate IEEE 802.15.4 UWB PHY schemes. Evaluation takes place over office, residential and outdoor IEEE channel models via Monte-Carlo simulation. Special attention is given to the highest rate (27.24 Mbps) scheme that suffers from intersymbol interference (ISI) over NLOS outdoor and residential channels. Optimum bit-to-symbol mapping (OBM), ISI cancellation and MLSE techniques are proposed and evaluated in conjunction with RAKE reception. Significant gains are attained with the proposed enhancements while keeping complexity low. On the other hand, the coverage range of high rate schemes is estimated for a given BEP. It is deduced that 27.24 Mbps and 6.81 Mbps schemes are well applicable to all LOS channels. However, the maximum allowable transmission power deteriorates range in NLOS cases. Overall, high rate schemes are shown to deserve more attention in the context of high rate sensor applications.

In modern day society the increase of data generation and transfer has been an issue that researchers are working on. This generated and shared data might have a different purpose but one thing is certain, the reception. This communication can cover continents, countries, cities or even just a few meters. For the purpose of the later, personal area networks (PAN) have been created with a main focus to lower the energy consumption. The protocol that is created under IEEE is 802.15.4 and it has multiple applications in the context of next generation sensor networks. This thesis investigates the performance IEEE 802.15.4 UWB PHY for high data rates over IEEE multipath fading channels and introduces receivers aiming to diversity and to mitigate the intersymbol interference (ISI) that might appear. We simulate the protocols highest mandatory data rate over slow, block faded, realistic IEEE channel models such as, residential, office, outdoor and industrial. The simulation includes Reed Solomon (RS) channel coding, optimal successive erasure decoding (SED), and coherent RAKE receivers. We verify that the selective RAKE (sRAKE) perform better than the nonselective RAKE (n-sRAKE) in all environments and also the increase of fingers is mandatory in order to improve performance. In cases with low number of fingers the ISI mitigation techniques like Maximum-Likehood Sequence Estimator (MLSE) & RAKE combination or Maximum Ration Combining (MRC) ISI cancellation receivers, can provide some gain in large delay spread environments. In cases with high number of ingers the MRC received employs its full diversity since the received power is arger than before. Overall the apply of optimal errors and erasures decoding can urther improve the system performance by adding a small gain, lowering existing it Error Probability (BEP) even more.

This paper proposes a successive coordinated power allocation (SCPA) scheme for orthogonal frequency division multiple access (OFDMA) systems based on the water-filling algorithm. The model assumes two transmitters belonging to heterogeneous cells, i.e. a macro cell and a micro/pico cell with predefined different power capabilities that cover a common geographical area over a channel that includes path loss and shadowing. The main idea is the reduction of the computation complexity and the minimization of information exchange between the two transmitters while preserving similar performance with the optimal cooperative power allocation (OCPA) joint transmission algorithm, recently proposed in the literature. The algorithms are evaluated via extensive Monte-Carlo simulations. The results show that the proposed algorithm provides similar sum rate than OCPA and presents a higher mean number of serving mobile units while reducing, at the same time, the complexity by roughly to orders of magnitude.