34 research outputs found
Multi-Antenna Coded Caching
In this paper we consider a single-cell downlink scenario where a
multiple-antenna base station delivers contents to multiple cache-enabled user
terminals. Based on the multicasting opportunities provided by the so-called
Coded Caching technique, we investigate three delivery approaches. Our baseline
scheme employs the coded caching technique on top of max-min fair multicasting.
The second one consists of a joint design of Zero-Forcing (ZF) and coded
caching, where the coded chunks are formed in the signal domain (complex
field). The third scheme is similar to the second one with the difference that
the coded chunks are formed in the data domain (finite field). We derive
closed-form rate expressions where our results suggest that the latter two
schemes surpass the first one in terms of Degrees of Freedom (DoF). However, at
the intermediate SNR regime forming coded chunks in the signal domain results
in power loss, and will deteriorate throughput of the second scheme. The main
message of our paper is that the schemes performing well in terms of DoF may
not be directly appropriate for intermediate SNR regimes, and modified schemes
should be employed.Comment: 7 pages, 2 figure
Full-Duplex Wireless for 6G: Progress Brings New Opportunities and Challenges
The use of in-band full-duplex (FD) enables nodes to simultaneously transmit
and receive on the same frequency band, which challenges the traditional
assumption in wireless network design. The full-duplex capability enhances
spectral efficiency and decreases latency, which are two key drivers pushing
the performance expectations of next-generation mobile networks. In less than
ten years, in-band FD has advanced from being demonstrated in research labs to
being implemented in standards and products, presenting new opportunities to
utilize its foundational concepts. Some of the most significant opportunities
include using FD to enable wireless networks to sense the physical environment,
integrate sensing and communication applications, develop integrated access and
backhaul solutions, and work with smart signal propagation environments powered
by reconfigurable intelligent surfaces. However, these new opportunities also
come with new challenges for large-scale commercial deployment of FD
technology, such as managing self-interference, combating cross-link
interference in multi-cell networks, and coexistence of dynamic time division
duplex, subband FD and FD networks.Comment: 21 pages, 15 figures, accepted to an IEEE Journa
Thirty Years of Machine Learning: The Road to Pareto-Optimal Wireless Networks
Future wireless networks have a substantial potential in terms of supporting
a broad range of complex compelling applications both in military and civilian
fields, where the users are able to enjoy high-rate, low-latency, low-cost and
reliable information services. Achieving this ambitious goal requires new radio
techniques for adaptive learning and intelligent decision making because of the
complex heterogeneous nature of the network structures and wireless services.
Machine learning (ML) algorithms have great success in supporting big data
analytics, efficient parameter estimation and interactive decision making.
Hence, in this article, we review the thirty-year history of ML by elaborating
on supervised learning, unsupervised learning, reinforcement learning and deep
learning. Furthermore, we investigate their employment in the compelling
applications of wireless networks, including heterogeneous networks (HetNets),
cognitive radios (CR), Internet of things (IoT), machine to machine networks
(M2M), and so on. This article aims for assisting the readers in clarifying the
motivation and methodology of the various ML algorithms, so as to invoke them
for hitherto unexplored services as well as scenarios of future wireless
networks.Comment: 46 pages, 22 fig