Körner and Marton established the capacity region for the 2-receiver broadcast channel with degraded message sets. Recent results and conjectures suggest that a straightforward extension of the Körner-Marton region to more than 2 receivers is optimal. This paper shows that this is not the case. We establish the capacity region for a class of 3-receiver broadcast channels with 2 degraded message...

the aim of this research was to evaluate some soil physical quality indicators using remotely sensed date, gis and geostatistical methods in baft area that is one of the most important centers of agricultural production in kerman province. therefore, soil samples were collected from 0 to 20cm depth of 183 points based on regular sampling pattern (every 250 meters) and soil physical indicators i...

This paper derives outer bounds on the secrecy capacity region of the 2-user Z interference channel (Z-IC) with rate-limited unidirectional cooperation between the transmitters. First, the model is studied under the linear deterministic setting. The derivation of the outer bounds on the secrecy capacity region involves careful selection of the side information to be provided to the receivers an...

by Shiva Prasad Kotagiri In many communication scenarios, the communicating parties typically have some knowledge or attempt to learn about the time-varying environment or the channel over which communication takes place. To understand these models, it is important to study the fundamental performance limits of state-dependent channels whose probabilistic input-output relationship depends on a ...

A two-user Gaussian Z-Interference Channel (GZIC) is considered, in which encoders are connected through noiseless links with finite capacities. In this setting, prior to each transmission block the encoders communicate with each other over the cooperative links. The capacity region and the sum-capacity of the channel are characterized within 1.71 bits per user and 2 bits in total, respectively...

The capacity region for the discrete memoryless multipleaccess channel without time synchronization at the transmitters and receivers is shown to be the same as the known capacity region for the ordinary multiple-access channel. The proof utilizes time sharing of two optimal codes for the ordinary multiple-access channel and uses maximum likeliiood decoding over shifts of the hypothesized trans...

In this paper, we study the impact of channel output feedback architectures on the capacity of two-user interference channel. For a two-user interference channel, a feedback link can exist between receivers and transmitters in 9 canonical architectures, ranging from only one feedback link to four-feedback links. We derive exact capacity region for the deterministic interference channel and cons...

In this paper, we model energy-limited wireless ad hoc networks as non-transferable-utility cooperative network flow games. We define the %ore capacity region” of a wireless ad hoc network to be the set of Pareto-optimal utility vectors that cannot be blocked by any proper subset of the node set. We show that the core capacity region is non-empty under the linear utility model. Under the many-t...

This work concerns the behavior of “good” (capacity achieving) codes in several multi-user settings in the Gaussian regime, in terms of their minimum mean-square error (MMSE) behavior. The settings investigated in this context include the Gaussian wiretap channel, the Gaussian broadcast channel (BC) and the Gaussian BC with confidential messages (BCC). In particular this work addresses the effe...

In spectrum-sharing systems where the secondary user (SU) opportunistically accesses the primary user (PU)’s licensed channel, the SU should satisfy both the transmit power constraint of the SU transmitter and the received power constraint at the PU receiver. This letter studies the ergodic capacity of spectrum-sharing systems in fading channels. The ergodic capacity expression along with the o...