Fakultät für Technische Wissenschaften
OFDM multicarrier techniques are widely deployed in most wireless communication systems, in particular in cellular networks (LTE, LTE Advanced, 5G…), broadcast networks (DVB-T, DVB-T2, ATSC3.0…) and WiFi networks. However, multi-carrier modulations are characterized by a very large dynamic amplitude measured by the Peak to Average Power Ratio (PAPR). This large amplitude prevents radio frequency designers to feed the signal at the optimal point of the non linear High Power Amplifier (HPA) which reduces their energy efficiency and then increases dramatically the overall base station consumption. In literature, the PAPR reduction and the linearization techniques are the main approaches to solve this HPA efficiency problem in cellular and broadcast networks
In recent years, tone reservation (TR) PAPR reduction techniques have been deeply studied and included for example in the DVB-T2 and the new American digital video broadcasting (ATSC 3.0) standards. It is based on a gradient iterative approach where, at each iteration, a predefined kernel is used to reduce one peak in the time domain. During this talk, we will present novel TR PAPR reduction techniques, namely grouped individual carrier allocation for multiple peaks (GICMP) based on a new kernel signal and fully compatible with the new broadcasting DVB-T2 and ATSC3.0 standards. An in-depth performance analysis based on simulation and experimental results demonstrated that the novel proposed PAPR reduction algorithm offers very good performance/complexity/latency trade-off.
In the second part of this talk, we will present intelligent solution for future implementations to control the reduction of PAPR and the linearization steps in a flexible way according to some predefined parameters so that they become adaptive and self-configurable. More specifically, our work focused on the analytical analysis of in-band measured by the Error Vector Magnitude (EVM) and out-of-band distortions measured by the Adjacent Chanel Power Ratio (ACPR) for multicarrier signals taking into account the PAPR reduction, the impact of non-linear amplification, the memory effects and the predistortion. Combining those complementary approaches, the power efficiency of the transmitters with OFDM multicarrier waveforms can be highly upgraded and/or the energy consumption reduced by 10 to 15 %
Prof. Jean-François Hélard
Kerstin Smounig (kerstin [dot] smounig [at] aau [dot] at)