Fig 1: Smartsurface can lead to multiplexing gain

Fig 2: Polarization of an EM wave changes upon reflection and scattering and arrives at random at the UE

Fig 3: Antenna Polarization mismatch at the receiver causes signal loss

In the past , we have demonstrated how the multiplexing capability of the wireless channel can be increased by creating new multipath in the channel. We achieved this by designing smartsurfaces that can be deployed on walls as to create diverse paths from a UE to Basestation. The smartsurfaces create a strong reflection and makes the wireless channel well-conditioned to support multiple spatial streams.

Polar-RIS: Practical Limits of RIS Performance

Our research addressed a critical challenge in modern wireless communication: maximizing the performance of MIMO (Multiple-Input Multiple-Output) systems in crowded sub-6GHz frequencies. While MIMO technology enables faster data rates by transmitting multiple data streams simultaneously, its effectiveness depends heavily on maintaining strong, diverse signal paths between devices. Through detailed simulations and theoretical analysis, we demonstrated how subtle polarization mismatches-caused by device orientations and environmental reflections-severely degrade MIMO performance in real-world indoor environments. To overcome this, we developed Polar-RIS, an innovative smart surface technology that actively corrects polarization distortions while amplifying signals.

Media Article

Team Members

Peixing Li, UC San Diego

Dr. Manideep Dunna, UC San Diego

Golnaz Salehi, UC San Diego

Nagarjun Bhat, UC San Diego

Dr. Sajjad Nassirpour, SDSU

Dr. Xiaozhen Yang, UC San Diego

Alireza Vahid: PI, Rochester Institute of Technology

Daniel Sievenpiper: PI, UC San Diego

Dinesh Bharadia: PI, UC San Diego