Spherical Modes Driven Directional Modulation With a Compact MIMO Antenna

Abstract

In this letter, a compact beamsteering MIMO antenna is proposed for Directional Modulation (DM) applications. A generalization of the beamsteering principle is presented and by exploiting the antenna's unidirectional beamsteering capability within the entire azimuth plane, the system realizes secure steerable transmissions in the direction of the legitimate receiver, with a low Bit Error Rate (BER) of 10 −5 , while a high error rate of 10 −1 is seen outside the desired regions. Numerical and experimental verifications are carried out to validate the proposed concept and comparisons with circular arrays are conducted, revealing that the system achieves comparable performance but with up to 35% and 71% reduction in antenna diameter and profile, respectively. The method is proposed as a good candidate to enhance the security of small (IoT) devices.

Directional Modulation for Enhanced Privacy in Smartwatch Devices: Proposing a security solution compatible with Internet of Things devices [Bioelectromagnetics]

“…To realize beam steering within sizeconstrained spaces, the proposed multimodal ultrathin antenna exploits the different phase variations of each radiated mode-the method is detailed in [53]-and it is based on the fact that the E v -field at a large distance ( ) kr " 3 can be expressed as a weighted sum of the far-field spherical wave pattern functions Ksmn v defined as [54] ( , , )…”

“…Two DM schemes are studied with the proposed antenna. In scheme 1, all the complex patterns generated by exciting each port are used as DM weights, and artificial noise is added to scramble the IQ constellations in all undesired directions [53]. In scheme 2, only the complex patterns generated by a single port are used, with no excessive artificial noise in undesired directions [31].…”

Directional Modulation for Enhanced Privacy in Smart Watch Devices

“…To realize beamsteering within size-constrained space, the proposed multimodal ultra-thin antenna exploits the different phase variations of each radiated mode -the method is detailed in [53] and it is based on the fact that the ⃗ E-field at a large distance (kr → ∞) can be expressed as a weighted sum of the far-field spherical wave pattern functions ⃗ K smn defined as [54]…”

Sub-GHz Wrist-Worn Antennas for Wireless Sensing Applications: A Review

“…The smartwatch antenna in [125] demonstrated enhanced physical layer security through directional modulation using beam-steerable wrist-worn antennas. Furthermore, the antenna described in [126] utilizes the theory of spherical modes to design a 3D beam-steering MIMO antenna to enhance the physical layer security. While the antennas in [125], [126] are tailored for Sub-6 GHz frequencies (5.57 GHz and 5.75 GHz), the implementation of a similar beam-steerable design concept holds the potential for enhancing physical layer security in Sub-GHz wrist-worn antennas, facilitating secure communication over LoRaWAN, NB-IoT, and Sigfox wireless technologies.…”