M.Sc Student | Homri Adi |
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Subject | Oblivious Processing on a Gaussian Channel by a Fronthaul Constrained Relay |
Department | Department of Electrical Engineering | Supervisor | ? 18? Shlomo Shamai )Shitz( |
Full Thesis text | ![]() |
Relaying
exploits intermediate nodes to achieve communication between two distant nodes.
We examine the ‘oblivious’ relay system that is, the specific codebooks used
are unknown at the relay. In our setting, the transmitter conveys messages to
the receiver through a capacity-limited fronthaul connected relay. The channel
between the transmitter and the relay-station is modeled by a frequency
selective additive Gaussian noise channel. We provide a comprehensive survey of
relevant literature.
We find the reliable information rate that
can be achieved with Gaussian signaling,
and to that end, employ Gaussian bottleneck
results combined with Shannon’s incremental frequency approach. We also prove that
unlike classical water-pouring, the allocated spectrum (power and bit-rate) of
the optimal solution could be discontinuous, and sometimes do not employ all
available channel frequency resources. We further study the oblivious relay
operation under a limited entropy constraint of the quantized signal. This
facilitates application of distortionless universal compressors, such as the
Lempel-Ziv algorithm which are standard and
of limited complexity as compared to universal
source coding procedures. It is shown that in this setting a per symbol deterministic
quantizer is optimal. We present lower and upper bounds on the optimal
performance (in terms of mutual information), and derive an analytical
approximation.