Dissertations / Theses on the topic '100510 Wireless Communications'

Mobile communication technology is continuously evolving. Early Fifth generation (5G) products, due 2020, should support high capacity, higher data rates, lower la- tency, lower energy consumption and should be cost effective. High data rates will require wider bandwidths, which are available in the higher frequency millimetre wave (mmWave) bands. Millimetre waves have much shorter wavelengths compared to to- day’s microwave mobile systems. Understanding mmWave propagation characteristics is important in the physical layer design of future wireless systems. Statistical Channel models are required in the standardization process to evaluate implementation proposals without the expense of building costly hardware test-beds. Statistical channel models are described by a few key parameters and a variance. For example, transmission path loss is a function of environment, range, path loss exponent (PLE) and the standard deviation (σ) of a statistical (shadowing) component. These parameters are generated by fitting an equation, in a minimum mean square error (MMSE) fashion, to a collated measurement database from a number of research organizations in different countries. Considering this, a number of channel sounding empirical measurements at mmWave frequencies were conducted to characterize, model and evaluate the propagation chan- nel properties in different 3rd Generation Partnership Projects (3GPP) scenarios (envi- ronments) under Australian conditions. Particular outdoor areas of interest were Rural Macro (RMa), Urban Macro (UMa) and Urban Micro (UMi) while indoor areas (InH) of interest included office and shopping malls. An in-house channel sounder was modified to obtain signal strengths with respect to (wrt) location and angle of arrival (AoA). Angular resolution was nominally 10°, 20° and 55° depending upon the size of the horn antenna. The equipment covered frequencies between 24 GHz to 40 GHz and was capable of measuring path losses up to 160 dB with the appropriate antenna. The experimental work involved performing measurements in different scenarios and then comparing to existing channel models (if such exist) and suggesting improvements where appropriate. The thesis focuses on outdoor and out- door to indoor mmWave wireless propagation channels and contains contributions in each of the key scenarios as follows: Rural Macro (RMa) channel measurements were performed at 24 GHz. Average path loss and Angle of Arrival (AOA) spread were close to 3GPP predictions limited to sub 7 GHz frequencies. The results were submitted to the Third Generation Partnership Project (3GPP) enabling the extension of the existing RMa model to 30 GHz. Urban Macro (UMa) have base station (BS) antennas above roof-top height. Measure- ments at 27.1 GHz were performed in two environments; dense urban and light urban, both classified as NLOS UMa. The results were compared against two competing 3GPP path loss models; the alpha beta (AB) model and the close-in free space reference dis- tance (CI) model. The AB model had the lower RMS error. The AB model required input parameters such as average building height and street width etc. which made it sensitive to the choice of input parameters, whereas the CI model required no input pa- rameters and was preferred if the cell consists of wide variety of dense and light urban regions. Urban Micro (UMi) have BS antennas below roof-top height. Measurements were con- ducted at 39.5 GHz in Open Square (OS) and Street Canyon (SC) scenarios. Results showed that the extracted parameters are in close agreement with 3GPP specifications, particularly for the CI model. Additionally, we reported 31 dB for 100 m down the SC side streets out of which 18 dB loss occurs just around the corner. We further analysed the base station (BS) height gain effect in OS and found a marginal benefit of 0.5 dB for a 4 m height change. Cross polar discrimination were also reported in SC which reduced by 2.5 dB per 10 dB increase in path loss using directional antennas while correlation disappeared on a omnidirectional basis. We presented a double-directional measurements for an UMi OS environment. Results showed that multiple Angles of Departure from a given user equipment (UE) position often result in few (often one) Angles of Arrival at the BS. Similarly different UE lo- cations can often share a common angle of arrival at the BS. This could cause rank reduction in some MIMO system. An outdoor to indoor measurement campaign at 24 GHz emulating the satellite to in- door propagation channel was presented. The results are applicable to the satellite/mo- bile co-existence problem as well as in-building coverage from high altitude platform. The mean building entry loss increased by 0.43 dB per degree of (satellite) slant eleva- tion angle, almost twice the ITU recommendation. Further we showed that the signal linearly decays with distance with a slope that increases with slant angle. Additionally, we showed that high gain narrow beam antenna outperformed low gain wide beam an- tenna both in terms of signal maximization to high altitude platform as well as signal minimization to a co-existing satellite uplink channel. Further, there is an antenna gain reduction in this type of environment due to internally generated multipath.

This thesis focuses on the implementation of high resolution phase shifter devices for adaptive cancelling applications. Cancelling is a potential replacement for filtering in wireless handsets, where the area allocated to filtering is becoming excessive due to the growing numbers of transmission frequencies. Cancelling circuits have the potential to be integrated directly in silicon as part of the radio circuit. Adaptive cancelling requires precise adjustments of the gain and phase of the reference RF signal.

Intrabody communications (IBC) is a novel physical layer outlined in the recently ratified IEEE 802.15.6 Wireless Body Area Network (WBAN) standard. This data communication method uses the human body itself as the signal propagation medium.

The current trend in healthcare is the move towards proactive health monitoring and making health one’s responsibility. This has seen a proliferation of wearable devices that monitor physical and physiological parameters in real time. However, there is an increasing need to monitor internal body parameters, detect risks and act on them in a timely manner. Implanted medical devices (IMDs) are gaining recent attention due to their capability to provide diagnostic, therapeutic and assistive functionalities. With a projected annual growth of 7.1 % (2016- 2022) the global market share of IMDs is expected to reach 116.3 billion USD by year 2022. In Australia alone, the clinical use of remotely monitored IMDs has risen sharply from 987 (2013-14) to 2269 in just two fiscal years. The increasing demand for ubiquitous and minimally invasive implants is due to the prevalence of chronic disease and growing aging population. While bio-sensing and implant drug delivery techniques have improved tremendously, implant communication technology has advanced at a slower rate. This poses problems for the new generation of implants such as brain computer interfaces (BCI), controllers for artificial prostheses and bionics which will require higher data rates. Existing IMD communications are mainly enabled through antenna based radio frequency links that rely on electromagnetic (EM) wave propagation at ultra high frequencies (UHF). The Medical Device Radio Communication Services (MedRadio) band (401-406 MHz) and Industrial Scientific and Medical radio (ISM) band (2.4 GHz) are most commonly used. However, the human body has a high attenuation to signals at these high radio frequencies; as a result, transceivers tend to consume high power and require complex circuitry to mitigate channel attenuation effects. Lower RF frequencies (lower attenuation through the body) require larger antenna sizes resulting in larger implant sizes. On the other hand, while inductively coupled techniques use lower frequencies (lower path loss), they generally have a narrow transmission band and lower data rates. Thus, the race is on to develop new implant data transmission techniques that consume less power yet provide high (acceptably high) data rates. The thesis addresses this challenge by investigating an alternative implant communication technique using intrabody communication (IBC) mechanisms, specifically galvanically coupled IBC (gc-IBC). This communication method utilises the human tissue as a volume conductor for data communications. In this thesis we began by critically reviewing existing and emerging implant communications technologies. We then proposed and investigated gc-IBC as a new alternative implant communication technology. A novel analytical framework that modeled the human body as a communication channel was proposed. Simulation results were experimentally confirmed by measurements on phantom body solutions. The framework was then extended to analyse a hybrid communication scheme for cortical implants that utilised gc-IBC and the popular inductively coupled data transfer (ic-DT). It was found that for the same frequency range, gc-IBC offers a wider bandwidth for data transmission compared to ic-DT while ic-DT was better for wireless power transfer due to its narrow band characteristic and lower path loss at the resonant frequency. It was also shown that gc-IBC provided 20 dB lower path loss than antenna based RF schemes for the same transmit power. Then, an integrated sensor gc-IBC implant transceiver prototype was designed and developed to characterise and demonstrate the feasibility of implant communication using gc-IBC mechanism. The integration of the sensor into the transmitter was made in a way that minimises transmitter complexity which was crucial to achieve high degree of miniaturisation and low power consumption. Transceiver characterisation experiments were conducted using an automated mechatronic rig that is specifically designed and built for this work. The rig moves the receiver inside the phantom solution in the three axes with respect to the transmitter and is capable of computing the bit error rate (BER) of the reception. The transceiver demonstrated the feasibility of gc-IBC scheme for implants with a BER of 1.1 ×10−4 at signal to noise ratio (SNR) of 8 dB which is better compared to existing uncoded schemes. The gc-IBC channel noise was characterised for the first time as a function of transmission distance and was found to be -118 dB/Watt on average. Future work will focus on extending the framework to model more complex parts e.g., organs, channel capacity estimation under different setting, testing different coding schemes to improve transceiver performance and miniaturisation.

The popularity of smart phones, cloud computing and the growing market for machineto- machine communications is fuelling the growth of mobile broadband. More frequency bands are therefore being allocated to mobile services. Unfortunately, for historical reasons, these band allocations are fragmented, poorly harmonised between different countries and no longer large enough for the ever-increasing broadband data rates. Carrier aggregation, the operation on two or more bands at once, will be necessary. A future wireless terminal capable of global roaming would therefore have to handle 35 bands, and be capable of carrier aggregation. This is the research challenge. Duplexing is a technique to simultaneously transmit and receive information from the same antenna. Frequency Division Duplex uses two frequency bands for uplink and downlink communications, enabling the transmitter and receiver to operate continuously. Duplexing filters are essential for isolating the receiver from the strong self transmitted signal. Unfortunately the filters are expensive, non tunable and not suitable for integration into silicon. Each new frequency band requires its own duplexing filter and a complex array of switches and filters is required for multi-band operation This work presents an adaptive duplexer architecture compatible with silicon integration. It is tunable over a wide frequency range and capable of carrier aggregation. The structure uses a combination of a low isolation device with multiple analog cancelling loops controlled by a normalised least mean square algorithm to track changes in signal leakage. The control is a multi-input multi-output problem. However the use of the ”inverse plant control technique” enables orthogonalisation into multi single-input single-output problems, simplifying the structure and reducing convergence time over previous search algorithms. Convergence takes 10ms from ’cold’ and tracking has a latency of 1.5ms. Low power pseudo noise pilot signals placed in the receive bands measure the cancelling error residues used as feedback to the controller. The pilot generator is integrated into silicon using the Peregrine UltraCMOSr GC process. The generator was programmable to four sequence lengths and 8 delays for correlation purposes. The maximum chip rate of 100Mchip/s was more than the 10Mchip/s required for an LTE channel.

Increasing interest in self health monitoring and performance analysis has resulted in a growing number of human health sensor devices. Such devices usually take the form of small, wearable and battery powered electronic systems that emphasise low power consumption and minimum discomfort to the user. While such sensors may be helpful on their own, increased benefits can be realised though the implementation of an integrated sensor network around the human body. In 2012, the IEEE 802.15.6 standard was introduced to provide a common communications protocol that may be adopted by sensor devices using three types of physical layer communications methods: ultra wideband radio frequency, narrow band radio frequency and human body communications. While narrow band and ultra wideband communications utilise traditional electromagnetic wave propagation, human body communications relies on electrostatic coupling between the transmitter and receiver. Electrostatic coupling has the benefit of reduced attenuation when used in body area networking applications. This thesis presents an implementation of an IEEE 802.15.6 compliant transceiver using the human body communications physical layer. The thesis covers the design and implementation of the digital and analogue electronics necessary to meet the requirements of the standard, as well as describing a prototype transceiver that was developed to confirm correct operation of the design. The transceiver design has been developed in full for the purpose of this thesis. The prototype transceiver is capable of sustaining up to 763Kbps at a bit error rate of 0.21 at the maximum data date, or for improved quality of service, lower data rates may be used with a minimum bit error rate of 0.06. Complete FPGA proven hardware descriptions of the digital system are provided in addition to a mixed signal testbench, allowing end-to-end simulation of the entire communications channel.

The evolution of new telecommunication standards is increasingly leaning towards higher data transmission rates. The boundaries between digital and analog signal processing is impending closer to the antenna, therefore aiming for a software-defined radio solution. In terms of analog-to-digital converters (ADCs) of mobile terminal receivers, this indicates higher sample rate, lower power consumption and higher resolution. With comparison to other ADCs, the pipelined ADC architecture has most successfiilly covered the wide resolution limits and data rate requirements of these terminal receiver architectures. However, even though fix word-length pipeline ADC architecture could be a suitable device for the mobile receiver, it still has a distinct disadvantage when it comes to power consumption. In this thesis, the requirements of ADC of the mobile receiver architecture are studied and analysed using the system specifications of the 3rd Generation (3G) Wideband Code Division Multiple Access (WCDMA) standard.

This thesis considers the incorporation of cooperative relays into a cognitive radio network. Cognitive radio is a potential solution to the growing scarcity of radio spectrum and the increased demand for wireless services. Cooperative relay networks can help cognitive radios to improve their utilisation by reducing their transmit power. This allows a reduction in their interference footprint and increases their probability of accessing licensed spectrum, improving throughput, and/or coverage. A cognitive relay network model has been analysed to derive the closed-form outage probability expressions for the repetition-based and selection-based protocols. Both decode-and-forward and amplify-and-forward relaying schemes have been employed for these protocols. When the probability of spectrum availability is unity, the cognitive relay behaves as a conventional cooperative relay. An identical and independently distributed slow fading Rayleigh channel model has been assumed in the analysis. The outage probability expressions are valid for arbitrary signal-tonoise ratios. This is an improvement on the previously published work which was limited to high signal-to-noise ratio regimes.

The placement of base station transceivers at close proximity to one another is a major challenge for RF engineers. In a colocated setting, the base station receivers have to receive weak desired signals in the presence of high-power transmit/jamming signals from colocated base station transmitters; resulting in major interference issues. The thesis identifies two major mechanism of interference for the colocated victim receiver. First, the strong jamming signals mix within the victim receiver front-end to produce intermodulation products that may fall on its desired receive channel and cause interference. The strong signals may also saturate the receiver circuits and cause desensitization. Second, large jamming signals from one colocated transmitter can radiate into the antenna system of a second colocated transmitter. The signals enter the second transmitter in the reverse direction and mix in the output stage of its power amplifier to produce intermodulation products. These ‘reverse’ intermodulation products get radiated from the antenna system and may fall on the victim receiver’s desired channel.

Adaptive antenna arrays have recently been introduced to cope with the high capacity required by the 3rd generation (3G) wireless communications systems. As adaptive antenna arrays focus narrow high gain beams towards the desired user and nulls towards interferers, both coverage and capacity of the network can be improved. To establish the performance gain that a smart antenna can deliver in a 3G environment (i.e., with mixed traffic), the implementation of adaptive antenna arrays for the uplink of a Wideband Code Division Multiple Access (WCDMA) system in the Frequency Division Duplex (FDD) mode is addressed in this thesis. The beam-forming is implemented with a LS - DRMTA algorithm and a Lagrange multiplier based algorithm using the Q channel only. The results show that the adaptive antenna arrays offer significant performance enhancement over switched beam and single antennas in a 3G environment (i.e., with mixed traffic).

Fourth generation (4G) mobile communication systems will need wider band-width channels and improved spectrum efficiency to achieve the specified LTE-advanced 100Mbps (mobile) and 1Gbps (fixed) wireless transmission target rate. The next generation of wireless basestations will also need to be powered from renewable sources, particularly in developing countries. A new generation of components, circuits, algorithms and transmission structures will therefore be required to meet the wider bandwidth and the lower energy requirements. This thesis addresses the transmitter chain, which dominates the basestation power budget. In particular we consider pre-conditioning algorithms for a new generation of high efficiency radio frequency power amplifiers (RFPA).

The convergence of optical and wireless technologies has given rise to the fiber-wireless (Fi-Wi) network. This network combines the huge capacity of optical fiber with the ubiquity and mobility of wireless networks. Fiber to the premises (FTTP) combined with wireless local area network (WLAN) in home distribution is now becoming a reality. However, network congestion in the wireless access link still limits end user performance, especially in dense residential areas. Therefore, this thesis focuses on the enhancement of the wireless media in Fi-Wi networks. The thesis considers the realisation of Fi-Wi networks using the gigabit passive optical network (GPON) and the infrastructure based WLAN. The study shows the binary exponential backoff (BEB) adopted in the medium access control (MAC) pro- tocol for the IEEE 802.11 WLAN standard is the key factor inhibiting WLAN perfor- mance. The standard distributed coordination function (DCF) access method used by WLAN today provides equal chance of transmissions to all stations. This equal- ity can lead to unfairness between uplink (UL) and downlink (DL) transmissions because the number of active wireless users normally exceeds the number of access points. Generally the Fi-Wis access point (AP) requires greater media access than any of its associate wireless users (WUs) because of the predominance of downlink traffic. Thus, techniques to maximize the network throughput and provide fairness between UL and DL transmissions are proposed. Traffic information obtained from monitoring both GPON and WLAN networks is utilized in the proposed schemes.

The dramatic growth in aging population has opened up the opportunity for engineers and scientists to develop sophisticated devices, especially in supporting the elderly for safety navigation. Mobility assistive device is a supportive tool which can assist the elderly during walking either indoor or outdoor environment. The number of fall-related diseases among the elderly could be reduced using sensor based mobility assistive devices. These machines will grow further as new supportive tools of electronic devices for daily locomotion, and become more feasible and pervasive. Sensor embedded mobility assistive devices with wireless technology compatibilities are the solution to accommodate the elderly’s safety in navigation. The newly designed system must be highly reliable, efficient, hands-free, cheap and most importantly, practical for use in real life activities. These technologies are said to bring a number of significant improvements into the next generation of mobility assistive devices, including miniaturization, low power consumption, full integration of system capability and low cost of production. Miniaturization is a great advantage as it means that the devices or systems should require only small volumes of space and suitability to embed insole of shoes. With low power consumption, only small batteries might be needed as power supply or even energy scavenging can be sufficient to power them, if not a combination of these. As full system integration on a single chip is also possible, signal processing and computation can be performed on the same chip with greatly improved overall system performance. Most interestingly, the low per-unit cost is what business and consumers are looking for in every product and this has been a significant trend.

Wireless communications is on the brink of a major change. New technologies called multiple antenna systems (MIMO) and orthogonal frequency division multiple access (OFDMA) will be put together in the deployment of the next generation of cellular standards known as 4G. Consumers can expect peak data rates up to 160 Mbps. If the user is to have a good network experience with multimedia applications, then consistency in service data rates will be needed.

A sigma-delta (ΣΔ) based technique is used to embed a complex modulation scheme such as orthogonal frequency division multiplexing (OFDM) into a single ONOFF bit stream operating at the carrier frequency. The amplitude of the signal is related to the pulse widths and the phase is related to the pulse positions. The pulse edges are time quantised to align with the system clock. The work is based on a Cartesian ΣΔ scheme which uses Cartesian filters and a polar quantiser to move quantisation noise away from the band of interest. The first contribution of this thesis is the introduction of an improved odd quantisation and joint quantisation process. Odd quantisation uses pulse widths constrained to an odd number of clock periods compared to the more traditional even quantisation with an even number of clock periods. Joint quantisation uses pulses of unrestricted widths. It is shown that the odd quantisation scheme outperforms the even quantisation scheme by about 2 dB in terms of signal-to-noise ratio and the joint quantisation scheme enhances this by a further 3 dB. The improvement comes at the expense of complexity. A joint quantiser requires a two dimensional (2D) quantisation process, which for an oversampling ratio (OSRRF) of 8 involves 197 operations. A method that simplifies this to 44 operations is proposed. The second contribution involves the development of a new frequency tuning method. It involves phase rotators before and after the quantiser rotating at an intermediate frequency. Tuning spectrally shifts both the signal and noise null together, but the final phase conversion process generates an image and distortion products of both the noise and signal, resulting in a higher than expected noise floor and unwanted spurious signals. A deliberate choice of intermediate frequency (fIF) equal to or greater than the transmission bandwidth plus half of a channel bandwidth, will move all distortion products out of band. Unfortunately there is a deterioration in the in-band noise null compared to the non-shifted condition of about 8 dB and this worsens as the intermediate frequency increases. A mathematical derivation has been developed to predict the size and position of the unwanted images. The signal image can be removed by pre-distorting the input signal. A method for reducing noise enhancement caused by frequency tuning has also been developed. It involves distorting the feedback signal in the ΣΔ converter. The above improvements will enhance the use of all-digital ΣΔ based transmitters in future wireless communication system.

Human body composition refers to the relative proportions of fat, bone, water, muscle and minerals in the body. Adequate proportions of these are a primary requirement for healthy living. Measurement of body composition is important for medical diagnosis and for understanding the physiological proportions of body tissues for physical fitness and exercise performance. Studies in human body hydration, as an example, provides the information necessary to understand the desired fluid levels for optimal performance of the body's physiological and metabolic processes during exercise and activities of daily living. It can help identify, or quantify issues of ill-health or wellbeing, e.g. lymphoedema and risk of heart attack. This thesis proposes a new system for assessing human body hydration which measures changes in body fluid level in real time.

Over the past few years, there has been a growing need for wireless communications with higher data rates and ubiquitous coverage, and these must be achieved at reduced cost and with a lower carbon footprint. This evolution in wireless demand places a big burden on transmitter architectures. The need for higher efficiency has stimulated research into the potential replacement of current linear power amplifiers (PAs) by switch mode power amplifiers (SMPAs) at cellular frequencies. The radio frequency (RF) PA currently accounts for a significant part of the cost, and most of the power requirements of a typical wireless base station. This research is focused on the modulation and up-conversion circuits for generating the SMPA drive signals. The switched (‘on’/‘off’) nature of the amplifier drive signal creates an opportunity for an all-digital solution removing traditional analog components such as the digital to analog converters, reconstruction filters, quadrature modulator and local oscillators. Digital signal processing techniques used for signal modulation are extended to digital up-conversion to generate suitable drive signals for the SMPA. In this thesis, a sigma-delta (ΣΔ) based technique is used to embed a complex modulation scheme such as OFDM into a single ‘on’-‘off’ bit stream.

The electric power grid has been developed over the last century which lacks bi-directional flow of data. The advancement in Information and Communication Technology (ICT) has motivated to convert the existing grid into the Smart Grid. The Sensors, Intelligent Electronic Devices (IEDs), Phasor Measurement Unit (PMU), etc. are the backbone of Smart Grid network. The billions of installed components in Smart Grid will generate high volumes of operation and control data. Transferring this high-volume data in the Smart Grid network is a big challenge! The present communication technology has limitations in delivering the Big Data of Smart Grid to control center in real-time. This research explores the possibility of using IEEE802.22 international standard for communication of Big Data. IEEE802.22 uses Cognitive Radio for communication that allows opportunistic use of unused TV white space by Secondary User if that spectrum is not being used by Primary User. This study reflects on following the points: *(i) The prospects of Integrating IEC61850 with IEEE802.22; *(ii) Probability of sensing Primary User’s spectrum efficiently in real-time for optimum use of spectrum in Cognitive Radio; and *(iii) Verifying the feasibility of Cognitive Radio to meet the timing constraints (latency) of data transmission for power protection.

Existing wireless links using a single antenna element at the transmitter and receiver are heavily influenced by the multipath scattering arising from objects in the transmission environment. Unlike conventional systems, a concept referred to as Multiple-Input Multiple-Output or MIMO not only thrives under multipath conditions but also has the potential to allow for substantial increases in capacity. MIMO systems use a combination of multiple antenna arrays at the transmitter and receiver in conjunction with dedicated Digital Signal Processing (DSP). Before MIMO systems are designed and deployed, a database of typical propagation measurements is required to confirm theoretical predictions with reality. The design, development and use of specialised measurement equipment to accurately establish an indoor MIMO measurement database is presented in this thesis.

The advancement of sensing technology has successfully reduced the physical size of a sensor node and stimulated the application of swarm sensing (millimetre scale sensors). Such a system has been envisioned to provide novel applications. For example, CSIRO has commenced the application of swarm sensing technology to track insect that aims to understand how the environmental situation influences bee behaviour. While the micro-sensor is still under development, it is crucial to have a baseline data set for initial data analysis purposes so that reasoning with the rich data is possible once the hardware has been developed and deployed. This work will propose a field simulation to address this issue. A hybrid environmental sensor network will be deployed, for the purpose of making highly dense observations, that consists of: (i) fixed sensor nodes, acting as weather stations, that collect data in a regularly-spaced time interval; and (ii) mobile nodes that sense the environmental parameters while insects move within the region with extremely high frequency – i.e. seconds. The proposed spatio-temporal interpolation algorithm in this dissertation (i.e. for environmental modelling) has achieved a computational efficiency factor from highly-dense sample data with an acceptable statistical error. The method also reconstructs the environmental situation in reality – e.g., produce a smooth surface in space and over the time. Combination of a successfully developed field simulation and the interpolation algorithm has opened up a wide range of applications. For instance, researchers could infer bee behavioural dynamics based on the environmental changes that they are experiencing. Such activities could assist entomologists to deepen their understanding of bee behaviour, with a view to advance our knowledge of the decline in bee populations worldwide.

The human body has antenna characteristics that are not explored in detail to explain some phenomena involving the interaction of electromagnetic fields and the human body. Moreover, the characterization of the human body as antenna unlocks new applications in body area networks for low-power wireless communications by utilizing the human body itself as an antenna. This thesis presents a new theory for explaining the antenna characteristics of the human body in transmission and reception mode. The theory is applied to two areas of study, namely, Human Body Communication (HBC) and whole-body radio-frequency (RF) dosimetry. Based on this, the thesis proposes a new concept where the human body is utilized as an antenna for wireless implant communication.