IEEE Future Directions
Related Articles
As we have reached the Shannon limit in terms of squeezing bits in a single Hz researchers are looking at circumventing that limit by using several parallel “channels”. This is what happens with MIMO, Multiple Input Multiple Output. The radio signal is generated from and received by multiple antennas (this requires a significant amount of processing power and this explains why this technology has become practical in the last few years). Additionally, researchers have created antennas that can direct a radio beam in a specific direction (a normal antenna would create a radio signal that propagates as a growing sphere): beamforming technology, making antenna “smart”.
Now a new company, Pivotal, is proposing a holographic beamforming technology that promises to multiply the capacity of today’s MIMO, albeit being based on MIMO.
Beamforming modulates the signals emitted by an array of antennas both in amplitude and phase to direct the propagation of the radio signal in a desired direction. The technology proposed by Pivotal allows a better manipulation of the radio signal both in elevation and azimuth thus giving the possibility to focus on a specific point (where the receiver is). This increases the signal strength at the reception point which in turns by increasing the signal to noise ratio allows the packaging of more bits per Hz (we are back at Shannon limit…).
The manipulation of the radio waves is achieved using metamaterials. These have specific structural characteristics that allow the manipulation of radio waves in the desired shape. It is yet another area where advances in materia technology is providing benefits.
Beamforming and 5G is a good combination.