2 research outputs found
The capacity for the linear time-invariant Gaussian relay channel
In this paper, the Gaussian relay channel with linear time-invariant relay
filtering is considered. Based on spectral theory for stationary processes, the
maximum achievable rate for this subclass of linear Gaussian relay operation is
obtained in finite-letter characterization. The maximum rate can be achieved by
dividing the overall frequency band into at most eight subbands and by making
the relay behave as an instantaneous amplify-and-forward relay at each subband.
Numerical results are provided to evaluate the performance of LTI relaying.Comment: 5 pages, 3 figures. Submitted to ICASSP 201
A joint time-invariant filtering approach to the linear Gaussian relay problem
In this paper, the linear Gaussian relay problem is considered. Under the
linear time-invariant (LTI) model the problem is formulated in the frequency
domain based on the Toeplitz distribution theorem. Under the further assumption
of realizable input spectra, the LTI Gaussian relay problem is converted to a
joint design problem of source and relay filters under two power constraints,
one at the source and the other at the relay, and a practical solution to this
problem is proposed based on the projected subgradient method. Numerical
results show that the proposed method yields a noticeable gain over the
instantaneous amplify-and-forward (AF) scheme in inter-symbol interference
(ISI) channels. Also, the optimality of the AF scheme within the class of
one-tap relay filters is established in flat-fading channels.Comment: 30 pages, 10 figure