arXiv subjects

Yong Peng

Publications and source records attributed to Yong Peng.

41 records · Page 3Linked to original sources

arXiv2009

Noisy DPC and Application to a Cognitive Channel

In this paper, we first consider a channel that is contaminated by two independent Gaussian noises $S ~ N(0,Q)$ and $Z_0 ~ N(0,N_0)$. The capacity of this channel is computed when independent noisy versions of $S$ are known to the transmitter and/or receiver. It is shown that the channel capacity is greater then the capacity when $S$ is completely unknown, but is less then the capacity when $S$ is perfectly known at the transmitter or receiver. For example, if there is one noisy version of $S$ known at the transmitter only, the capacity is $0.5log(1+P/(Q(N_1/(Q+N_1))+N_0))$, where $P$ is the input power constraint and $N_1$ is the power of the noise corrupting $S$. We then consider a Gaussian cognitive interference channel (IC) and propose a causal noisy dirty paper coding (DPC) strategy. We compute the achievable region using this noisy DPC strategy and quantify the regions when it achieves the upper bound on the rate.

cs.IT↗

arXiv2009

Capacity Bounds of Half-Duplex Gaussian Cooperative Interference Channel

In this paper, we investigate the half-duplex cooperative communication scheme of a two user Gaussian interference channel. We develop achievable region and outer bound for the case when the system allow either transmitter or receiver cooperation. We show that by using our transmitter cooperation scheme, there is significant capacity improvement compare to the previous results, especially when the cooperation link is strong. Further, if the cooperation channel gain is infinity, both our transmitter and receiver cooperation rates achieve their respective outer bound. It is also shown that transmitter cooperation provides larger achievable region than receiver cooperation under the same channel and power conditions.

cs.IT↗

arXiv2008

On the Capacity Equivalence with Side Information at Transmitter and Receiver

In this paper, a channel that is contaminated by two independent Gaussian noises $S ~ N(0,Q)$ and $Z_0 ~ N(0,N_0)$ is considered. The capacity of this channel is computed when independent noisy versions of $S$ are known to the transmitter and/or receiver. It is shown that the channel capacity is greater then the capacity when $S$ is completely unknown, but is less then the capacity when $S$ is perfectly known at the transmitter or receiver. For example, if there is one noisy version of $S$ known at the transmitter only, the capacity is $0.5\log(1+\frac{P}{Q(N_1/(Q+N_1))+N_0})$, where $P$ is the input power constraint and $N_1$ is the power of the noise corrupting $S$. Further, it is shown that the capacity with knowledge of any independent noisy versions of $S$ at the transmitter is equal to the capacity with knowledge of the statistically equivalent noisy versions of $S$ at the receiver.

cs.IT↗

arXiv2003

Helix vs. Sheet Formation in a Small Peptide

Segments with the amino acid sequence EKAYLRT appear in natural occurring proteins both in $α$-helices and $β$-sheets. For this reason, we have use this peptide to study how secondary structure formation in proteins depends on the local environment. Our data rely on multicanonical Monte Carlo simulations where the interactions among all atoms are taken into account. Results in gas phase are compared with that in an implicit solvent. We find that both in gas phase and solvated EKAYLRT forms an $α$-helix when not interacting with other molecules. However, in the vicinity of a $β$-strand, the peptide forms a $β$-strand. Because of this change in secondary structure our peptide may provide a simple model for the $α\to β$ transition that is supposedly related to the outbreak of Prion diseases and similar illnesses.

cond-mat.soft↗

arXiv2002

Solution effects and the order of the helix-coil transition in polyalanine

We study helix-coil transitions in an all-atom model of polyalanine. Molecules of up to length 30 residues are investigated by multicanonical simulations. Results from two implicit solvent models are compared with each other and with that from simulations in gas phase. While the helix-coil transition is in all three models a true thermodynamic phase transition, we find that its strength is reduced by the protein-solvent interaction term. The order of the helix-coil transition depends on the details of the solvation term.

cond-mat.stat-mech↗