Results 191 to 200 of about 1,051,474 (226)

A hybrid access method in a multiple access channel

Performance Evaluation, 1986
Abstract This paper considers a multiple-access communication channel with an infinite number of users. We show that if a controlled slotted Aloha protocol is used, then messages with variable length will have a negative impact on the average message delay.
openaire   +1 more source

The Cost of Synchronizing Multiple-Access Channels

Proceedings of the 2015 ACM Symposium on Principles of Distributed Computing, 2015
Multiple access channel is a communication model in which many users, also called stations, could exchange information. Since it offers limited capacity, some information sent through it might be lost due to signal interference (collision). Therefore, successful message delivery to a station requires breaking symmetry on the channel.
Tomasz Jurdzinski, Grzegorz Stachowiak
openaire   +1 more source

Multiple-Access Channels With Confidential Messages

IEEE Transactions on Information Theory, 2008
A discrete memoryless multiple-access channel (MAC) with confidential messages is studied, where two users attempt to transmit common information to a destination and each user also has private (confidential) information intended for the destination. This channel generalizes the classical MAC model in that each user also receives channel outputs, and ...
Yingbin Liang, H. Vincent Poor
openaire   +1 more source

Multiple access Gaussian channels with feedback

53rd IEEE Conference on Decision and Control, 2014
We consider the problem of multiple access communication with feedback, and show that the well known schemes of Ozarow and Kramer may be represented as feedback systems with a marginally unstable decoder. Other approaches represent these schemes as feedback systems with a strictly unstable encoder.
James S. Freudenberg, Richard H. Middleton   +1 more
openaire   +1 more source

Decoding for multiple-access channels

2005
We discuss some results in coding and decoding for multiple-access channels. A new approach to choosing codes and users' energies for that channel is described. For the case when a bit error probability and a decoding complexity are fixed we construct a region of achievable code rates.
openaire   +1 more source

The multiple access channel with an untrusted relay

2014 IEEE Information Theory Workshop (ITW 2014), 2014
This paper considers a Gaussian multiple access channel aided by a relay. Specifically, the relay facilitates communication between multiple sources and a destination to which the sources have no direct link. In this set up, the relay node is considered to be untrusted, i.e., honest but curious, from whom the source messages need to be kept secret.
Ahmed A. Zewail, Aylin Yener
openaire   +1 more source

Mismatched decoding and the multiple-access channel

IEEE Transactions on Information Theory, 1996
An achievable region is derived for the multiple-access channel under decoding mismatch conditions. It is shown that achievable rates higher than the random coding capacity of the single-user mismatched channel can sometimes be demonstrated by treating the single-user channel as a multiple-access channel. Refining these ideas we derive a lower bound on
openaire   +1 more source

Extending the capacity of multiple access channels

IEEE Communications Magazine, 2000
Multiple access techniques which allow a communication medium to be shared between different users represent one of the most challenging topics in digital communications. In terms of the number of users that can be accommodated on a given channel, there are two distinct classes of multiple access techniques. The first class includes the well-known FDMA,
Hikmet Sari, Frederik Vanhaverbeke, Marc Moeneclaey   +2 more
openaire   +1 more source

On multiple access channels with asymmetric feedback

2008 IEEE International Symposium on Information Theory, 2008
In multiuser systems, the downlink capacity to different users is often different due to the near-far effect. We capture this asymmetry in the feedback link by introducing an asymmetric feedback model where different users get different amount of channel feedback from the base-station.
Vaneet Aggarwal, Ashutosh Sabharwal
openaire   +1 more source

On the capacity of multiplicative multiple access channels with AWGN

2011 IEEE Information Theory Workshop, 2011
We consider a multiplicative multiple access channel in the presence of additive white Gaussian noise. Under individual average power constraints at each of the transmitters, we characterize the capacity region of this channel. The structure of the region reveals some fundamental characteristics related to timesharing, power constraints and the ...
openaire   +1 more source