Defence of dissertation in the field of Signal Processing for Communications, Lic.Sc. (Tech.) Markku Kiviranta
The title of thesis is ” Spectral and Power Efficient Modulation Methods in Presence of Nonlinear Distortions”
Future wireless 5G systems will enable faster, more energy efficient and reliable communications. For cost-effectiveness, it is important that 5G is backward com-patible with 4G devices. In this thesis, the constant envelope orthogonal frequency division multiplexing (CE-OFDM) where phase modulation creates a constant envelope is studied, and the results indicate that the CE-OFDM has an advantage compared to the OFDM when the power amplifier efficiency is taken into account. In phase modulation, spectral spreading and detection performance are con-trolled using a modulation index. However, in a simple analog implementation, the modulation index deviates during the transmission and generates time vary-ing phase jitter. In the thesis, a new adaptive modulation index estimator is pre-sented in the receiver to improve detection performance. This thesis also intro-duces a technique by which trellis coded modulation (TCM) can be prevented from becoming a catastrophic code in the presence of phase noise. Today, the TCM is applied to the development of high-speed copper and fiber connections, for example, for households. Therefore, the thesis provides methods also for signal design when seeking synergies to implement future wired and wireless data transfer methods.
Opponent: Professor Markku Renfors, Tampere University of Technology
Supervisor: Professor Risto Wichman Aalto University School of Electrical Engineering, Department of Signal Processing and Acoustics
Markku Kiviranta, p. +358 40 589 0642, firstname.lastname@example.org
Teknologian tutkimuskeskus VTT Oy, Kaitoväylä 1, 90571, Oulu