Godkända
Reduction of Crosstalk Distortion in 5G
Ali Al-qamaji ()
Start
2019-02-04
Presentation
2019-06-03 09:15
Plats:
E:2349
Avslutat:
2019-09-30
Examensrapport:
Sammanfattning
Future 5G wireless technology is coming faster than expected to our day-to-day lives through many applications, e.g., Internet of Things (IoT) devices, sensors, and smartphones, etc. It has been estimated that about over 50 Billion devices will join the world network by 2020 and increase in data traffics to reach 24.3 Exabyte per month by 2019. To handle that, we will need high data rate and advanced wireless solutions. For higher data rate, we cannot depend on bandwidth for wireless communication, as frequency spectrum is getting scarce. In addition, advanced antenna system (AAS), i.e., Multiple input multiple output (MIMO), or massive MIMO, is one of the central enabling radio technologies for 5G cellular systems that significantly boost the provided data rates for data-hungry applications run by densely distributed users. These AAS are mainly requires multiple antennas for transmission and radio frequency (RF) power amplifiers (PAs). The RF PAs are the most energy consuming components, as this part is crucial to amplify the transmitted signal to be detectable at the receiver, hence the energy efficiency of any base station (BS) significantly relays on the RF PAs efficiency. Furthermore, the input power back-off (IBO) is crucial part to keep the input-output signal within linear region of the amplifier, and to avoid spectral regrowth due to in-band and out-of-band distortion, giving increase to both amplitude/amplitude modulation (AM/AM) and amplitude/phase modulation (AM/PM) nonlinear distortion. Hence, this will reduce the quality of the transmitted based on 3GPP standards and thus the performance of the MIMO communication system will be degraded. Currently, the signals generated from cross talk and mismatch are prevented using high quality and therefore expensive isolators. In our thesis, we will reduce these non-linear distortion effects by using digital pre-distortion (DPD) to reduce the number of isolators. This technique aims to apply the inverse of distortion to PA input to compensate the istortions of PA and gives linear amplification to the input.
Handledare: Liang Liu (EIT) och Ove Edfors (EIT)
Examinator: Fredrik Rusek (EIT)