Every new generation of wireless networks delivers faster speeds and more functionality than the previous one. 1G brought us the first phone, 2G let us text messages, 3G connected us to the internet and 4G gave us the speed and capabilities that we use today. However, the insatiable and ever-increasing demand for higher data rates and data traffic due to the introduction of several new applications (IoT, Video streaming, Gaming, V2V communication etc), required the development of a new technology capable of handling higher speeds and orders of magnitude higher data rates while being energy efficient, low cost, robust and reliable. This led to the generation of the 5G New Radio (5G NR). Millimeter waves, small cells, massive MIMO and beamforming are among the dominant technologies which will be used in 5G NR to address the aforementioned challenge. Millimeter wave frequencies will give access to larger bandwidth in order to achieve higher data rates, while massive MIMO will improve the spectral efficiency by using beamforming. Deployment of a dense network of small cells will alleviate the signal attenuation which is dominant at higher frequencies.
This project will focus on the RF transmitter of a 5G massive MIMO base station system with the aim to maximize its efficiency while complying to demands on modulation and (insertion) phase accuracy. Such a system typically consists of an up-converter and an RF power amplifier per antenna element. To achieve high efficiency and simultaneously reasonable linearity, self-calibration and self-healing techniques as well as digital predistortion are going to be used for each up-converter - power amplifier combination that drives an antenna element used in the massive MIMO system.