Assistant Professor

Associate Professor

Postdoctoral Researcher

Title:

Multi-antenna Coded Caching for Enhanced Wireless Content Delivery

Time: Thursday, May 2nd 2024, 16:15 – 19:15

 

Abstract:

Multi-antenna coded caching combines a global caching gain proportional to the cumulative cache size found across the network. An additional spatial multiplexing gain stems from using multiple transmitting antennas. However, a closer look reveals a few severe bottlenecks that hinder its practical implementation:

1. The well-known exponential sub-packetization bottleneck dramatically reduces performance when the communicated file sizes are finite.
2. The considerable optimization complexity of beamforming multicast messages when the SNR is finite.
3. The near-far issue limits the attainable performance at any multicast group to the achievable rate of the user with the worst channel conditions within the group.

In this tutorial, we investigate these three major impediments and review the related literature. For the sub-packetization bottleneck, we first check solutions based on single antenna transmitters and then provide an overview of recent multi-antenna schemes with novel interference cancellation techniques resulting in much smaller sub-packetization requirements. For the beamformer design, we introduce efficient reduced-complexity schemes where the spatial multiplexing gain and multicast group sizes are adjusted intelligently. Finally, for the near-far issue, we show how location-dependent caching techniques can be used to alleviate the problem by allocating larger cache portions for data likely to be requested in locations with poor wireless connectivity. Specifically, we consider an emerging immersive viewing application and illustrate how such uneven cache placement of location-dependent multimedia content can help achieve a more evenly distributed quality of experience within the application environment.

 

Biography:

Seyed Pooya Shariatpanahi received the B.Sc., M.Sc., and Ph.D. degrees from the Department of Electrical Engineering, Sharif University of Technology, Tehran, Iran, in 2006, 2008, and 2013, respectively. He is currently an Assistant Professor with the School of Electrical and Computer Engineering, University of Tehran. Before joining the University of Tehran, he was a Researcher with the Institute for Research in Fundamental Sciences (IPM), Tehran. His research interests include information theory, network science, wireless communications, and complex systems. He was a recipient of the Gold Medal at the National Physics Olympiad in 2001.

Antti Tölli is an Associate Professor with the Centre for Wireless Communications (CWC), University of Oulu. He received the Dr.Sc. (Tech.) degree in electrical engineering from the University of Oulu, Oulu, Finland, in 2008. From 1998 to 2003, he worked at Nokia Networks as a Research Engineer and Project Manager both in Finland and Spain. In May 2014, he was granted a five-year (2014-2019) Academy Research Fellow post by the Academy of Finland. During 2015-2016, he visited EURECOM, Sophia Antipolis, France. From August 2018 till June 2019, he visited the University of California Santa Barbara, USA. He has authored numerous papers in peer-reviewed international journals and conferences and several patents, all in signal processing and wireless communications. His research interests include radio resource management and transceiver design for broadband wireless communications, emphasizing distributed interference management in heterogeneous wireless networks. From 2017 to 2021, he served as an Associate Editor for IEEE Transactions on Signal Processing.

Mohammad Javad Salehi received the B.Sc., M.Sc., and Ph.D. degrees from the Department of Electrical Engineering, Sharif University of Technology, Tehran, Iran, in 2010, 2012, and 2018. Since 2019, he has been a postdoctoral researcher at the Center for Wireless Communication (CWC) at the University of Oulu, Finland. His main research interests include multi-antenna communications and wireless coded caching.