Ultra-wideband technology: Prospective solution for 5G ultra-small cell networks

Exhaustive research is being done to establish the technologies and standards of the fifth generation (5G) of wireless communication systems. Some of the most challenging requirements of 5G systems are to increase the spectral efficiency and the capacity by a factor of 10 and 1,000, respectively. New technologies must offer an adequate framework for the 5G uses cases, which will enable higher capacities and the flexibility to adapt to dynamic scenarios. To cope with these challenging demands, a compelling approach is to exploit the current radio service bands by means of spectrum sharing and cooperation techniques, which alleviate the bandwidth requirements. In addition, advanced modulation schemes have a fundamental role in ensuring the best usage of the spectrum available in band-limited systems. In this manuscript, we present the ultra-wideband (UWB) technology as a prospective solution for 5G picocells and femtocells. Its main feature is its capability to operate simultaneously, without introducing interference, with current radio services on an unlicensed basis. We report experimental results reaching data rates up to 35 Gbit/s using the multiband approach of carrierless amplitude phase (MB-CAP) modulation. To validate the versatility of the proposed system, our experimental tests were performed under the UWB regulations defined by the United States' Federal Communications Commission (FCC), the European Electronic Communications Committee (ECC), and the Russian State Committee for Radio Frequencies (SCRF). The regulations chosen provide diversity enough to demonstrate the capacity of MB-CAP modulation to comply with worldwide regulations.