Tutorial 2: Modeling and Design of mmWave networks for spectral and energy efficiency in 5G
- Monday, 12 June 2017, 13:30-17:00, Room IT105
- Alessio Zappone (University of Cassino and Southern Lazio, Italy)
- Stefano Buzzi (University of Cassino and Southern Lazio, Italy)
Motivation and Context
The number of devices connected to the Internet is larger than the size of the world population, and it is increasing at an exponential rate. By 2020, there will be more than 50 billion devices and the volume of IP traffic will reach tens of Exabytes per month. To support such a high traffic demand, 5G networks will have to provide 1000 times higher data rates than present systems. A considerable portion of this gain will be achieved by scaling up carrier frequencies. Indeed, communication in the range 10-100 GHz, a.k.a. mmWave, is one of 5G strongest candidate technologies. Coupled with high beamforming gains, the reduced wavelength permits packing many antennas in small volumes, enabling massive MIMO systems. For some applications, such as wireless backhauling and V2X Communications, the use of large scale antenna arrays at both sides of the communication link is also foreseen, a configuration known as doubly massive MIMO. Of course, increasing the number of transceiver antennas at mmWave leads to an increase of the consumed energy, thus bringing forth the crucial problem of energy efficiency for mmWave communications.
Present wireless communication networks consume more than 3% of the world-wide energy, and this percentage will rapidly increase with the increase of connected devices. In order to guarantee a sustainable growth, the 1000x increase of the data rate required by 5G, needs to be achieved without increasing the power consumption, as explicitly acknowledged by the Next Generation Mobile Networks (NGMN) Alliance, which states in its 2015 manifesto: “5G should support a 1000 times traffic increase in the next 10 years time-frame, with an energy consumption by the whole network of only half that is typically consumed by today's networks. This leads to the requirement of an energy efficiency increase of x2000''.
Structure and Content
The tutorial is organized into four main parts, with the following table of contents.
a) The spectrum crunch in 5G
b) The energy crunch in 5G
c) mmWaves and energy efficiency as enablers of 5G
- Modeling of mmWave communications
a) Propagation characteristics for mmWave frequencies
b) MIMO Channel model at the mmWaves
c) Massive MIMO mmWave system modeling
- Design of mmWave communications
a) Spectral Efficiency versus Energy Efficiency
b) Resource allocation in mmWave networks with hybrid beamforming
c) Fundamentals of fractional programming theory
d) Optimization framework for mmWave networks
- Conclusions and Future Challenges
a) Take-home messages
b) Open challenges and research issues