Browsing Engineering by Journal
Now showing items 1-3 of 3
Analysis of sub-channel correlation in dual-polarised MIMO systems via a polarisation diversity schemeA polarisation diversity combing scheme for dual-polarised multiple-input and multiple-output channels in small cell environments introduced and evaluated. The scheme is based on post analysis of channel measurement data captured from scenarios and includes indoor-to-indoor, indoor-to-outdoor, and indoor-outdoor-indoor propagation. An analysis of link signal strength and correlation with respect to frequency and polarisation revealed profound differences between copolarised and cross-polarised links in terms of received signal strength and correlation between frequencies. Utilizing these differences, a polarisation diversity combing scheme is evaluated which is shown to produce an average of 10.6-dB polarisation diversity gain.
Authentication in millimeter-wave body-centric networks through wireless channel characterizationAdvent of 5G technologies has ensued in massive growth of body-centric communications (BCC), especially at millimeter-wave frequencies. As a result, the portable/handheld terminals are becoming more and more “intelligent” but not without the cost of being less secure. Improved authentication measures need to be explored, as effective identity authentication is the first level of security in these devices. This paper presents a novel keyless authentication method exploiting wireless channel characteristics. Human palm has distinct transmission coefficient (S21) for each of the users and is used for in-vivo fingerprint identification in this work. A detailed channel modeling using data acquisition from real environment and empirical approach is adopted to evaluate the usability of this method. The results show that this method can provide a secure operation for the millimeter-wave 5G BCCs.
A low profile antenna for millimetre-wave body-centric applicationsMillimetre-Wave frequencies are a front runner contender for the next generation body-centric wireless communications. In this paper, design of a very low profile antenna is presented for body-centric applications operating in the millimetre-wave frequency band centred at 60 GHz. The antenna has an overall size of 14£10.5£1.15 mm3 and is printed on a flexible printed circuit board. The performance of the antenna is evaluated in off-body, on-body and body-to-body communication scenarios using a realistic numerical phantom and verified through measurements. The antenna has a bandwidth of 9.8 GHz and offers a gain of 10.6 dBi in off-body (free space) configuration while 12.1 dBi in on-body configuration. It also acheives an efficiency of 74% in off-body and 63% in on-body scenario. The small and flexible structure of the antenna along with excellent impedance matching, broad bandwidth, high gain and good efficiency makes it a suitable candidate to attain simultaneous data transmission/reception at millimetre-wave frequencies for the 5G body-centric applications.