This paper proposes a novel construction, calledduplex, closely related to the sponge construction, that acceptsmessage blocks to be hashed and—at no extra cost—provides digests on the input blocks received so far. It can be proven equivalent to a cascade of sponge functions and hence inherits its security against single-stage generic a acks. The main application proposed here is an authenticat...

Metasurface (MTS) antennas are based on the transformation of a cylindrical-wavefront surface wave (SW) into general wavefront leaky (LW). The MTS aperture is constituted by grounded dielectric slab printed with an electrically dense distribution subwavelength patches realizing space-variable, homogenized tensor impedance boundary conditions (IBCs). One challenges in this type antenna related t...

Downlink beamforming techniques with low signaling overhead are proposed for joint processing coordinated (JP) multi-point transmission. The objective is to maximize the weighted sum rate within joint transmission clusters. As the considered weighted sum rate maximization is a nonconvex problem, successive convex approximation techniques, based on weighted mean-squared error minimization, are a...

Dynamic time-division duplexing (TDD) enables adjustments of uplink (UL) and downlink (DL) resources flexibly according to the instantaneous traffic load. Long-Term Evolution (LTE) systems can be implemented in TDD mode (TD-LTE). However, the dynamic change of a TDD configuration has not been well supported and investigated. In large macro cells, the high transmit power of base stations (BSs) e...

The recent European Telecommunications Standards Institute (ETSI) decision to endorse for the Universal Telecommunication Radio Access ??? (UTRA) techniques based upon wideband-CDMA approaches for terrestrial UMTS (T-UMTS) paired frequency duplexing band will certainly constitute an important driver to orientate the corresponding choice for the satellite UMTS (S-UMTS) component. In this paper i...

We investigate the joint uplink-downlink configuration of an intelligent reflecting surface (IRS) for multi-user frequency-division-duplexing (FDD) and time-division-duplexing (TDD) systems. This is motivated in FDD since uplink downlink transmissions occur simultaneously hence IRS must be jointly configured both transmissions. In TDD, while a design not strictly necessary, it can significantly...

With the envisioned massive Internet-of-Things (IoT) era, one of the challenges for 5G wireless systems will be handling the unprecedented spectrum crunch. A potential solution has emerged in the form of spectrum sharing, which deviates from a monopolistic spectrum usage system. This article investigates the medium access control (MAC) as a means of increasing the viability of the spectrum shar...