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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.
Minimal mean-square error for 3D MIMO beamforming weightingThe 3D MIMO beamforming system needs a weighting method to determine the direction of beam whist reducing the interference for other beam areas operating at the same carrier frequency. The challenge is to determine the weights of the 3D MIMO beams to direct each beam towards its cluster of user terminals while placing its nulls at undesired user directions to minimise undesired interference. Therefore, the signal-to-interference-plus-noise ratio should be increased while the interference from the side lobes of the other beams reduced. A weight determining method is presented that constructs horizontal and vertical array weights, respectively, by minimising the mean-square error between the array pattern vector and the unit vector, where the unit vector expresses the desired direction for the array pattern and zero vector expresses the undesired direction. Since the rectangular planar array can be viewed as M linear arrays of N elements, the weight of the M–Nth element can be obtained based on the horizontal and vertical array weights.
Multiband split-ring resonator based planar inverted-F antenna for 5G applications5G, the fifth generation of wireless communications, is focusing on multiple frequency bands, such as 6GHz, 10GHz, 15GHz, 28GHz, and 38GHz, to achieve high data rates up to 10 Gbps or more.The industry demands multiband antennas to cover these distant frequency bands, which is a task much more challenging. In this paper, we have designed a novel multiband split-ring resonator (SRR) based planar inverted-F antenna (PIFA) for 5G applications. It is composed of a PIFA, an inverted-L parasitic element, a rectangular shaped parasitic element, and a split-ring resonator (SRR) etched on the top plate of the PIFA.The basic PIFA structure resonates at 6GHz. An addition of a rectangular shaped parasitic element produces a resonance at 15GHz. The introduction of a split-ring resonator produces a band notch at 8GHz, and a resonance at 10GHz, while the insertion of an inverted-L shaped parasitic element further enhances the impedance bandwidth in the 10GHz band. The frequency bands covered, each with more than 1GHz impedance bandwidth, are 6GHz (5–7GHz), 10GHz (9–10.8GHz), and 15GHz (14-15GHz), expected for inclusion in next-generation wireless communications, that is, 5G. The design is simulated using Ansys Electromagnetic Suite 17 simulation software package.The simulated and the measured results are compared and analyzed which are generally in good agreement.