Programmable Wireless Channel for Multi-User MIMO Transmission Using Meta-Surface

Optimal Multi-user Transmission based on a Single Intelligent Reflecting Surface

“…In [15], we briefly presented that a single piece of the IRS is able to support MU transmission. However, the spatial multiplexing of a single IRS was not discussed in the paper.…”

“…To be noted, there is a trade-off between energy efficiency and spacing as well. The origin of trade-off is due to smaller spacing resulting in a smaller number of channel rank and larger beamwidth, but the redundant beam that causes energy waste in trivial directions is less likely to occur [15]. Thus, based on specific considerations, the actual spacing can be less than this value.…”

On Half-Power Beamwidth of Intelligent Reflecting Surface

“…By referring to existing model [11], the equivalent channel H from Tx to Rx by considering IRS weights can be written as…”

“…By solving ( 13) we obtain AF h = 0.707. Thus, by referring to (11) and (12), the relationship between the incident angle θ in and 3-dB bandwidth point θ out,h is given by…”

Millimeter-Wave Radar Scheme With Passive Reflector for Uncontrolled Blind Urban Intersection

“…Recent advances in metamaterials offer the prospect of deploying smart surfaces, or intelligent reflecting surfaces (IRS), that can manipulate EM channels. For example, the so-called programmable channel concepts in the context of multi-user multiple-input and multiple-output (MU-MIMO) transmission and beamforming are studied in [23]. In [24], IRS technologies are emerging as an important paradigm for the realisation of smart radio environments, where large numbers of small, low-cost and passive elements reflect the incident signal with an adjustable phase shift.…”