This thesis is germane to body-centric communication measurements and analyses at different frequency bands. It presents measurements and analyses of the radio channels for humans. This research contains a novel and comprehensive study of body-centric single input multiple output (SIMO) diversity. This has included the analyses of diversity techniques with off-body communications in different settings within indoor environments. The objectives in this research are; investigating the benefits of using multiple antennas for off-body and on-body channels and studying the performance of diversity antennas for off-body in different environments with both genders.
A further novel aspect of this thesis has been concerned with off-body channel characteristics using software defined radio (SDR) and LabVIEW using different modulation schemes for measurements and analyses. This method combines processing and control in software, paired with SDR for the over the air interface. The combination of SDR and LabVIEW is shown to provide a platform to facilitate experiments in the presence of humans that is useful for prototyping different types of radio channels. This method also gives a new aspect for a novel treatment of a 2x2 body-centric multiple input multiple output (MIMO) system. It is shown how the difficulties associated with implementing MIMO systems can be overcome by using SDR combined with LabVIEW.
Studying the effects of water in the body-centric communication channels are also a new area of research presented here. This work has shown how water encapsulated within Polyacrylamide gel can be exploited as a cheap and available material to enhance the performance of on-body antennas. It is shown that water gives 1–3dB enhancements from the measurements of SIMO and MIMO systems with the human presence.
A Doctoral Thesis. Submitted in partial fulfilment of the requirements for the award of Doctor of Philosophy of Loughborough University.