ComNum - Seminars

September,28 2018 [ComNum seminar] Cloud Radio Access Networks, Distributed Information Bottleneck, and more

Seminar Author(s):

Shlomo Shamai (Technion, Israel)

Seminar description:

at 11am in F900,


We consider transmission over a cloud radio access network (CRAN) focusing
on the framework of oblivious processing at the relay nodes (radio units),
i.e., the relays are not cognizant of the users' codebooks.
This approach is motivated by future wireless communications
(5G and beyond) and the theoretical results connect to a variety
of different information theoretic models and problems.
First it is shown that relaying a-la Cover-El Gamal, i.e.,
compress-and-forward with joint decompression and
decoding, which reflects 'noisy network coding,' is optimal.
The penalty of obliviousness is also demonstrated to be
at most a constant gap, when compared to cut-set bounds.
Naturally, due to the oblivious (nomadic) constraint the CRAN problem
intimately connects to Chief Executive Officer (CEO) source(s) coding
under a logarithmic loss distortion measure.
Furthermore, we identify and elaborate on some interesting
connections with the distributed information bottleneck model for which we
characterize optimal tradeoffs between rates (i.e., complexity) and
information (i.e., accuracy) in the discrete and vector Gaussian frameworks.
Further connections to 'information combining' and 'common reconstruction'
are also pointed out. In the concluding outlook, some interesting problems
are mentioned such as the characterization of the optimal input distributions
under users' power limitations and rate-constrained compression at the
relay nodes,


Joint work with: I.E. Aguerri (Paris Research Center, Huawei France)
A. Zaidi (Universite Paris-Est, Paris) and G. Caire (USC-LA and TUB, Berlin)
The research is supported by the European Union's Horizon 2020 Research And
Innovation Programme: no. 694630.


Wigger Michele

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