6 month Internship with Railenium
Influence of pilot signals on TD-LMMSE performance in the context of 5G waveforms and high speed varying channels.
Location: Ifsttar F-59650 Villeneuve d’Ascq
Tutors: Marion Berbineau (Ifsttar), Michel Saideh (IFSTTAR), Iyad Dayoub (UVHC)
Context and Objectives
In the context of the North Europe Region Smarties project from ELSAT 2020 program some research works are focusing on the development of adaptable wireless communications resilient to technology evolutions and to interferences able to answer the railway needs. In this context, in order to evaluate the new wireless system performance, we need to evaluate new channel estimation techniques I the context of 5G.
5G communication systems are still under research and they are expected to answer different needs in the high speed railway sector. Many 5G waveform candidates have been proposed recently to replace the 4G OFDM waveform due to its well-known disadvantages. The different structures of these newly proposed waveforms have urged the need to study and analyze new transceiver design techniques (e.g., Precoding, Channel Estimation (CE), Equalization…). Since having a good channel estimate is critical to the performance of the overall communication system, too many researches have focalized upon the channel estimation techniques. However, in the high speed railway environment, the Doppler spread induce inter carrier interference which becomes challenging. A Time Domain LMMSE channel estimation technique has been recently proposed by adopting a comb pilot pattern. It has shown a very good performance with the 4G OFDM technique in handling the high speed challenges and it has been analyzed for some 5G waveforms.
It has been shown how the performance of this CE technique is highly depending upon the pilot sequence. Hence, we are interested in analyzing the effect of the pilot signal on the performance of the TD-LMMSE in order to propose and conduct a pilot optimization study.
The missions will be to first understand the work principle of some 5G waveform candidates (e.g., FBMC, GFDM…). Then the student will study and analyse the TD-LMMSE technique in a multipath time varying channel scenario. It will be then necessary to optimize the pilot signal to have the optimal TD-LMMSE performance for the studied 5G waveform candidates. The work will be performed with Matlab simulations.
-  Nissel, R., Schwarz, S., & Rupp, M. (2017). Filter Bank Multicarrier Modulation Schemes for Future Mobile Communications. IEEE Journal on Selected Areas in Communications.
-  Kalakech, A., Berbineau, M., Dayoub, I., & Simon, E. P. (2015). Time-domain LMMSE channel estimator based on sliding window for OFDM systems in high-mobility situations. IEEE Transactions on Vehicular Technology, 64(12), 5728-5740.
Main skills: Wireless communications, signal processing, informatics, mathematics, Matlab, very good level of English, writing, knowledge of Railway domain will be a plus
Kow-how: Autonomy, sense of initiative, excellent relationship, rigor, taste for experiments