SBIR Phase I: Large Arrays for 5G MU-MIMO Wireless Access Operating in mm-wave Frequency Bands

Period of Performance: 07/01/2017 - 02/28/2018


Phase 1 SBIR

Recipient Firm

RF Pixels, Inc.
3340 Walnut Ave St 112 Array
Fremont, CA 94538
Firm POC, Principal Investigator


The commercial potential of this project lies in enabling much needed high wireless data rates and equal quality of service (QoS) to both densely populated areas as well as remote rural areas. 4G cellular and WiFi networks are facing a bottleneck due to proliferation of wireless devices and limited spectrum available in the currently allocated bands for wireless communications. Improving data connectivity would require new physical fiber to be laid out which is becoming impractical due to high costs vs. return on investment. The Federal Communications Commission has opened more spectrum in the mm-wave frequency spectrum (between 28-70 GHz) for mobile users to alleviate some of these issues. This project will enable spectrally efficient communication through frequency reuse for spatially separated mobile users in the mm-wave frequencies. It will also allow low cost dense deployment of 5G cellular base-stations to boost QoS. With this new paradigms in human machine interaction using machine learning can be advanced further. Remote educational programs, virtual and augmented reality (VR/AR) based learning, online health care and other new services around Internet of Things will be enhanced by better wireless connectivity. These technologies will uplift people?s lives delivering major economic and broad societal impact. This Small Business Innovation Research Phase I project proposes a revolutionary architecture that will enable massive multi-user MIMO techniques for mm-wave wireless systems to solve the spectrum scarcity issue. The mm-wave radio front end module (FEM) can reuse the same frequencies for spatially diverse mobile users with active beamforming thus enhancing the capacity of current cellular networks by 100x. A multitude of modules (1000s) will be used in a large array as a part of the mm-wave FEM making it crucial to achieve excellent power efficiency at the module level. This project will investigate a variant of Doherty power amplifier (PA) architecture to achieve highly efficient mm-wave transmitter. Module to module variation and within module variations can disturb accurate beamforming capability. Impact of these variations on forming coherent beams will be studied. A new method to calibrate a large array to tune out any module to module variation will be proposed through sufficient redundancies incorporated in the module design. Low sensitivity to calibration errors will be achieved while also trying to lower the calibration time. A new algorithm that achieves accurate simultaneous tracking of spatial mobile users to within 5-degrees using the new architecture will be proposed.