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In this paper, for the first time, we propose two new solutions to boost the data rate between small connected objects such as glasses and cams and the 5th generation (5G) mobile network, based on spatial modulation, single carrier waveform, compact reconfigurable antennas at the object side and massive multiple input multiple output (M-MIMO) at the network side. In the first new wireless communication system, a "transmitting object" uses transmit spatial modulation with a compact reconfigurable antenna and a constant envelop amplifier to transmit in high data rate with a low complexity and low power consumption. The space-time digital processing capability of the M-MIMO 5G base station is used to detect such signal. In the second new wireless communication system, a "receiving object" uses receive spatial modulation, a compact multiport antenna and a low complexity detection algorithm to receive in high data rate with a low complexity signal processing. The space-time beamforming capability of the M-MIMO 5G base stations is exploited to deliver a signal that is pre-equalized enough to be detected by the object. For the first time, we present experiments showing that M-MIMO allows for the reintroduction of single carrier modulation waveform. For the first time, we present performance results obtained with real existing compact antennas and compact reconfigurable antennas, showing that the two new communication systems outperform conventional modulation in terms of energy efficiency and complexity.INDEX TERMS Spatial modulation (SM), receive antenna shift keying (RASK), beamforming, multiple input multiple output (MIMO), Reconfigurable Antennas, Compact Antennas.

Sixth generation (6G) mobile networks may include new passive technologies, such as ambient backscatter communication or the use of reconfigurable intelligent surfaces, to avoid the emission of waves and the corresponding energy consumption. On the one hand, a reconfigurable intelligent surface improves the network performance by adding electronically controlled reflected paths in the radio propagation channel. On the other hand, in an ambient backscatter system, a device, named tag, communicates towards a reader by backscattering the waves of an ambient source (such as a TV tower). However, the tag's backscattered signal is weak and strongly interfered by the direct signal from the ambient source. In this paper, we propose a new reconfigurable intelligent surface assisted ambient backscatter system. The proposed surface has two features: it controls the reflection of an incident wave coming from the exact source location towards the tag and reader locations (creating hot spots at their locations), thanks to passive reflected beams from a predefined codebook. The surface also applies a common phase-shift to the beam. We demonstrate experimentally that by tuning the beam and the phase-shift of the reconfigurable intelligent surface, we can improve significantly the performance of ambient backscatter communications.

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International audienceThe design of a highly directive metamaterial-based cavity antenna for a 2.46 GHz application is reported. The proposed structure. is evolved from a Fabry-Perot (FP) cavity with a patch antenna acting as the feed and four metallic walls on the lateral sides. One of the two reflectors is the antenna's ground plane and the other is made from a bilayered metamaterial-based partially reflecting surface (PRS) constituted by a capacitive and an inductive grid. Calculations together with experimental results obtained from the fabricated prototype are presented. The results show a high directivity and low levels for the secondary lobes compared to a 2 X 2 patch antenna array. (c) 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1393-1396, 2009: Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.2439