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In next generation wireless communication systems, packet-oriented data transmission will be implemented in addition to standard mobile telephony. We take an information-theoretic view of some simple protocols for reliable packet communication based on \Hybrid-ARQ", over a slotted multiple access Gaussian channel with fading and study their through-put(More)
This paper studies the throughput performance of HARQ (hybrid automatic repeat request) protocols over block fading Gaussian channels. It proposes new protocols that use the available feedback bit(s) not only to request a retransmission, but also to inform the transmitter about the instantaneous channel quality. An explicit protocol construction is given(More)
An Interference Channel with Generalized Feedback (IFC-GF) is a model for a wireless network where several source-destination pairs compete for the same channel resources, and where the sources have the ability to sense the current channel activity. The signal overheard from the channel provides information about the activity of the other users, and thus(More)
—The capacity region of the interference channel in which one transmitter non-causally knows the message of the other, termed the cognitive interference channel, has remained open since its inception in 2005. A number of subtly differing achievable rate regions and outer bounds have been derived, some of which are tight under specific conditions. In this(More)
The capacity of the Gaussian cognitive interference channel, a variation of the classical two-user interference channel where one of the transmitters (referred to as cognitive) has knowledge of both messages, is known in several parameter regimes but remains unknown in general. In this paper we provide a comparative overview of this channel model as we(More)
—We consider multiaccess, broadcast, and interference channels with additive Gaussian noise. Although the set of rate pairs achievable by time-division multiple access (TDMA) is not equal to the capacity region, the TDMA achievable region converges to the capacity region as the power decreases. Furthermore, TDMA achieves the optimum minimum energy per bit.(More)
We consider a source that transmits to a receiver by routing the information packets over a communication network and examine rate benefits that finite complexity processing at the intermediate nodes may offer. We show that the processing capabilities of the intermediate nodes affect not only the end-to-end achievable rate, but also the optimal routing(More)
—We make use of the deterministic high-SNR approximation of the Gaussian cognitive radio channel to gain insights in deriving inner and outer bounds for any SNR. We show that the derived bounds are at most 1.87 bits apart for any SNR. I. INTRODUCTION Advancements in wireless technology have enabled the cooperation among devices, ensuring faster and more(More)