Although it is well known that feedback does not increase capacity of an additive white Gaussian channel, Yanagi gave the necessary and sufficient condition under which the capacity Cn,FB(P ) of discrete time non-white Gaussian channel is increased by feedback. In this paper we show that the capacity Cn,FB(P ) of the Gaussian channel with feedback is a concave function of P , and give two type ...

The capacity region of a two-user Gaussian multiaccess channel with intersymbol interference (ISI), where the inputs pass through respective linear systems and are then superimposed before being corrupted by an additive Gaussian noise process, is found. A novel geometrical method is given to obtain the optimal input power spectral densities and the capacity region. This method can be viewed as ...

For a quantum channel with additive Gaussian quantum noise, at the large input energy side, we prove that the one shot capacity is achieved by the thermal noise state for all Gaussian state inputs, it is also true for non-Gaussian input in the sense of first order perturbation. For a general case of n copies input, we show that up to first order perturbation, any non-Gaussian perturbation to th...

We derive a closed-form expression for the capacity of the additive-Gaussian-noise memoryless channel with binary input. The capacity expression that we obtain contains an infinite series. Truncation of the series -for computation reasonsat an odd or even number of terms results in a lower or upper, respectively, bound on the channel capacity; we prove that the tightness of the bound increases ...

We prove the equivalence of an arbitrary single-mode Gaussian quantum channel and a newly defined fiducial channel preceded by a phase shift and followed by a Gaussian unitary operation. This equivalence implies that the energy-constrained classical capacity of any single-mode Gaussian channel can be calculated based on this fiducial channel, which is furthermore simply realizable with a beam s...

We propose a new turbo encoding scheme for high spectral efficiency with performance close to the Gaussian channel capacity. The scheme combines nonuniform signaling on a Gaussian channel, and pragmatic turbo coded modulation for simple and flexible implementation. A table is used to map equiprobable input symbols into non equiprobable points in the QAM constellation. It is shown that the new s...

We consider an AWGN channel with a transmitter powered by an energy harvesting source. The node is equipped with a finite energy buffer. Such a system can be modelled as a channel with side information (about energy in the energy buffer) causally known at the transmitter. The receiver may or may not have the side information. We prove that Markov energy management policies are sufficient to ach...