Post date: 25-feb-2017 9:00:12

Title: Random Access Scheme for Sporadic Users in 5G

Date: 17-1-2017

Aula: 312 Aulario III

Material: pdf slides video

Speakers: Riku Jänttiis

Riku Jänttiis an Associate Professor (tenured) in Communications Engineering and the head of the department of Communications and Networking at Aalto University School of Electrical Engineering, Finland. He received his M.Sc (with distinction) in Electrical Engineering in 1997 and D.Sc (with distinction) in Automation and Systems Technology in 2001, both from Helsinki University of Technology (TKK). Prior to joining Aalto (formerly known as TKK) in August 2006, he was professor pro tem at the Department of Computer Science, University of Vaasa. Prof. Jäntti is a senior member of IEEE and associate editor of IEEE Transactions on Vehicular Technology. He is also IEEE VTS Distinguished Lecturer (Class 2016). The research interests of Prof. Jäntti include radio resource control and optimization for machine type communications,cloud based Radio Access Networks, spectrum and co-existence management and RF Inference.

Abstract:

Machine-Type Communication (MTC) devices usually have low data rate, and in some applications latency is critical. In Long-Term Evolution (LTE), establishing a connection requires a relatively complex handshaking procedure. Such an approach is suitable for a system serving only a few high-activity users, but it becomes cumbersome for MTC traffic where large amounts of low activity users intermittently transmit a small number of packets. We propose Random Access Channel (RACH) based scheme for the future 5G system that allows MTC users to send small packets within the random access burst. Device activity detection, channel estimation, authentication and data decoding are performed simultaneously from the same access burst. In addition to the inherent reduction in energy consumption, the scheme eliminates the signaling overhead and creates more resources for data transmission. We have constructed analytical framework for detection performance of Multiple-Input-Multiple-Output (MIMO) receiver in a frequency-selective channel. This has been validated it with simulations, and results show that a one-shot correlate-and-cancel algorithm is sufficient for activity detection and channel estimation when the base station either employs multiple receive antennas or schedules multiple resource blocks for MTC RACH.