Improved Broadband Wireless Connectivity With A New Communication Design

A paper published in the IEEE Journal on Selected Areas in Communications , by Konstantinos Dovelos and Boris Bellalta, members of the Wireless Networking research group, with the participation of researchers from Queen's University Belfast (UK).

Current wireless networks, for example, WiFi, LTE-Advanced, etc., operate on the lower end of the radio spectrum, below 6 GHz. Experts warn that soon this band will become congested due to the explosive growth of data traffic. An estimated 17,722 million connected devices in 2024.

To meet the growing and ubiquitous demand for broadband wireless connectivity, communication via terahertz (THz) bandwidth (0.1 - 10 THz) is seen as a necessary option for 6G networks. and beyond, due to the large amount of spectrum available at these frequencies.

A paper published in the IEEE Journal on Selected Areas in Communications presents a new communication design that improves broadband wireless connectivity. Konstantinos Dovelos and Boris Bellalta from the research group have participated

Wireless Networking , from the Department of Information and Communication Technologies ( DTIC ) at UPF and the IoT Lab , in collaboration with Michail Matthaiou and Hien Quoc Ngo , researchers at Queen's University in Belfast (UK).

To mitigate the propagation losses of THz signals
Despite the potential of wireless links in the THz band to achieve terabit bandwidths per second, THz signals suffer severe propagation losses due to their short wavelength. However, the use of multiple transmission and reception antennas following Massive Multiple-Input Multiple-Output (MIMO) techniques allows to compensate for these losses, while extending the range of communication by forming beams or Beam Forming.

The formation of beams basically consists of concentrating and directing the radiated electromagnetic signal optimally between the emitter and the receiver. In order to be able to use the formation of beams, however, it is necessary to know carefully the channel between the sender and the receiver, reason for which different techniques from estimation of the same exist.

A new design that mitigates signal delays
The ultra-large bandwidths of THz band transmissions make standard beamforming and channel estimation techniques ineffective. In the article published in the IEEE Journal on Selected Areas in Communications (JSAC), we have shown that when the signal propagation time between the transmitter's own antennas exceeds the symbol time of the data to be sent, the response of the set of This aspect, typically assumed in the design of current beam shaping techniques, makes them ineffective for use in the THz band, which our proposal resolves by adjusting these delays. in a controlled way ”, indicates Konstantinos Dovelos , first author of the article.

And adds Dovelos : "In addition, with the subtle design of the channel estimator we have presented, the transmitter can obtain reliable information on the state of the channel with a low estimation cost, minimizing the impact on the gain in link capacity ".

The numerical results obtained in this work show the performance gains offered by the design proposed by these researchers compared to the use of techniques developed without taking into account the essential characteristics of the THz band, paving the way for the achievement of multi-Gbps speeds at distances of several meters.