Ultra wideband antenna diversity characterisation for off-body communications in an indoor environment

In this study, spatial diversity is experimentally investigated for ultra wideband (UWB) off-body channels. Diveristy gain (DG) is calculated for various off- to on-body channels in different indoor locations and the impact of variation of inter-spacing between diversity branch antennas on mutual coupling, correlation and power imbalance is discussed. Effect on DG with respect to small variations of antenna on the body and DG behaviour with change of orientation between off-body transmitter and on-body diversity receiver are discussed. Also subject specific off-body diversity, uplink and downlink diversity are explored in this study. Result demonstrates that neither orientation nor subject changes or small variations in antenna position will affect the diversity performance severely. Comparison of off-body diversity shows an improvement of 50% with respect to on-body case; hence dominates the usefulness of UWB off-body diversity case in body-centric communications.