Very High-Speed Digital Subscriber Lines upstream transmission suffers from strong far end crosstalk (FEXT) by the shortest lines in a multiuser communication environment. This problem called “Near-Far Effect” drastically reduces the upstream capacity on the longer lines. Power control algorithms effectively handle this problem and maximize the achievable data rate region, given an average powe...

Without perfect channel state information at the transmitter, it is possible for adaptive transmission systems to experience information outage. In this paper, we formulate the throughput maximization with both an average power constraint and an information outage constraint. It is verified that, for the optimal transmission policy, the transmission only needs to adapt to a sufficient statistic...

This paper derives upper and lower bounds on the capacity of the multipleinput single-output free-space optical intensity channel with signal-independent additive Gaussian noise subject to both an average-intensity and a peak-intensity constraint. In the limit where the signal-to-noise ratio (SNR) tends to infinity, the asymptotic capacity is specified, while in the limit where the SNR tends to...

We present new capacity upper bounds for the discrete-time Poisson channel with no dark current and an average-power constraint. These bounds are a simple consequence of techniques developed by one of the authors for the seemingly unrelated problem of upper bounding the capacity of binary deletion and repetition channels. Previously, the best known capacity upper bound in the regime where the a...

A novel space-user approach to multiple-input-single-output (MISO) OFDM peak-to-average-power ratio (PAPR) reduction is examined. We propose two techniques that significantly reduce PAPR for MISO-OFDM at various userloads. The first exploits the degrees of freedom in the channel’s null-space (transmit weight optimization), while the second provides a more robust and higher reduction by further ...

The capacity of multiple-input multiple-output (MIMO) systems employing reconfigurable apertures (RECAPs) is carefully analyzed with a realistic thermal noise model for three different power constraints: average receive signal-to-noise ratio (SNR), maximum effective isotropic radiated power (EIRP), and average transmit power. Performance is studied not only for a noise-limited single link, but ...

Consistency Techniques have been studied extensively in the past as a way of tackling Constraint Satisfaction Problems (CSP). In particular various arc consistency algorithms have been proposed, originating from Waltz's filtering algorithm [20] and culminating in the opt imal algorithm AC-4 of Mohr and Henderson [13]. AC-4 runs in 0(ed) in the worst case where e is the number of arcs (or constr...