5 research outputs found
Optimizing The Spatial Content Caching Distribution for Device-to-Device Communications
We study the optimal geographic content placement problem for
device-to-device (D2D) networks in which the content popularity follows the
Zipf law. We consider a D2D caching model where the locations of the D2D users
(caches) are modeled by a Poisson point process (PPP) and have limited
communication range and finite storage. Unlike most related work which assumes
independent placement of content, and does not capture the locations of the
users, we model the spatial properties of the network including spatial
correlation in terms of the cached content. We propose two novel spatial
correlation models, the exchangeable content model and a Mat\'{e}rn (MHC)
content placement model, and analyze and optimize the \emph{hit probability},
which is the probability of a given D2D node finding a desired file at another
node within its communication range. We contrast these results to the
independent placement model, and show that exchangeable placement performs
worse. On the other hand, MHC placement yields a higher cache hit probability
than independent placement for small cache sizes.Comment: appeared in Proc. IEEE Intl. Symposium on Info. Theory, Barcelona,
Spain, July 201
Advanced DSP Techniques for High-Capacity and Energy-Efficient Optical Fiber Communications
The rapid proliferation of the Internet has been driving communication networks closer and closer to their limits, while available bandwidth is disappearing due to an ever-increasing network load. Over the past decade, optical fiber communication technology has increased per fiber data rate from 10 Tb/s to exceeding 10 Pb/s. The major explosion came after the maturity of coherent detection and advanced digital signal processing (DSP). DSP has played a critical role in accommodating channel impairments mitigation, enabling advanced modulation formats for spectral efficiency transmission and realizing flexible bandwidth. This book aims to explore novel, advanced DSP techniques to enable multi-Tb/s/channel optical transmission to address pressing bandwidth and power-efficiency demands. It provides state-of-the-art advances and future perspectives of DSP as well