In this paper the cognitive interference channel with a common message, a variation of the classical cognitive interference channel in which the cognitive message is decoded at both receivers, is studied. For this channel model new outer and inner bounds are developed as well as new capacity results for both the discrete memoryless and the Gaussian case. The outer bounds are derived using bound...

We explore the degrees of freedom region for the 3 user wireless interference channel with perfect channel knowledge at all nodes. While the best known outerbound for the K user interference channel states that there cannot be more than K/2 degrees of freedom, it has been conjectured that in general the constant interference channel with any number of users has only one degree of freedom. We sh...

A simply described achievable rate region is obtained for the genie-aided cognitive radio channel using the Han-Kobayashi celebrated jointly decoding strategy for the interference channel and the Gel’fandPinsker coding scheme for channels with side information known at the transmitter, and then is simplified by Fourier-Motzkin elimination. The obtained achievable rate region (i) extends the Cho...

In this work we revisit the multiplexing gain, or degrees of freedom, of the Gaussian cognitive radio channel. Prior work has shown that the cognitive radio channel attains one degree of freedom, indicating that while cognition significantly improves rates over the interference channel at medium SNR, at high SNR the cognitive channel too is interference-limited. In this work we show that by all...

Bluetooth is a short-range wireless technology that operates in the 2.4GHz unlicensed ISM band, so it will inevitably encounter the interference from other wireless systems and other Bluetooth piconets. Because of the flexible, efficient and reliable spectrum access by adapting the radio’s operating characteristics to the real-time conditions of the environment, cognitive radio technology is ap...

co-channel interference is a major factor in limiting the capacity and link quality in cellular communications. as the co-channel interference is modeled by lognormal distribution, sum of the co-channel interferences of neighboring cells is represented by the sum of lognormal random variables (rvs) which has no closed-form expression. assuming independent, identically distributed (iid) rvs, the...

The cognitive interference channel with confidential messages is studied. Similarly to the classical two-user interference channel, the cognitive interference channel consists of two transmitters whose signals interfere at the two receivers. It is assumed that there is a common message source (message 1) known to both transmitters, and an additional independent message source (message 2) known ...

While the best known outerbound for the K user interference channel states that there cannot be more than K/2 degrees of freedom, it has been conjectured that in general the constant interference channel with any number of users has only one degree of freedom. In this paper, we explore the spatial degrees of freedom per orthogonal time and frequency dimension for the K user wireless interferenc...