The requirements for the 5G networks include the support of 10 Gb/s data rates, 10-100 times the number of connected devices, 1000 times the traffic and 5 times lower end-to-end latency of the current 4G systems. In order to fulfil these expectations, a number of novel techniques and Radio Access Technologies need to be implemented. These include employment of millimeter wave (mmW) frequency bands that can accommodate the increased data rates/bandwidths as well as huge improvements in spectral efficiency and increased density of network through the use of small cells. The unique properties of the mmW signals (the need for LoS propagation, high isotropic attenuation, short wavelength) make the employment of beamforming both a necessity and an advantage. On the one hand, using a highly directive antennae allow for a compensation of the increased propagation attenuation. Employment of narrow beams directed at the user helps to reduce the interference in the dense network scenario. The short wavelength of the signal allows for reduced size of the antennae and possibility of deployment of antennae arrays consisting of a large no. of radiating units.
As the performance of the RF electronics degrades with the increased frequency, the employment of the photonics devices for the generation of the mmW signals becomes very attractive. In particular, the remote upconversion of baseband data to mmW
frequencies, through heterodyning of two highly coherent optical signals can allow for both OPEX and CAPEX savings.
In this project, the student is to investigate the possibility of realising a hybrid/analog beamforming for 5G networks by generating the required RF signals remotely and distributing them to the Remote Radio Units (RRU) using optical networks. The
student will be required to study the methods of generating the appropriate weights for the manipulation of the antenna radiation pattern and employ these methods to generate a Radio over Fibre (RoF) signal that, after being transmitted over the length of fibre, would be detected and fed to different antennae elements at the RRU.
The work would involve a co-simulation between a Virtual Photonics Inc. Transmission Maker tool (for simulation of the optical part of the system) and Matlab (for the wireless system simulation).
The investigation would focus on:
[login to view URL] of RoF signals using heterodyning of 2 optical tones
[login to view URL] the quality of the generated RF signal and the impact of fibre transmission.
[login to view URL] of propagation of the feeding signals over fibre (phase delay between signals transmitted over different wavelengths) on the beam shape