English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

In this paper, we consider single- and multi-user Gaussian channels withfeedback under expected power constraints and with non-vanishing errorprobabilities. In the first of two contributions, we study asymptoticexpansions for the additive white Gaussian noise (AWGN) channel with feedbackunder the average error probability formalism. By drawing ideas from Gallagerand Nakibo\u{g}lu's work for the direct part and the meta-converse for theconverse part, we establish the $\varepsilon$-capacity and show that it dependson $\varepsilon$ in general and so the strong converse fails to hold.Furthermore, we provide bounds on the second-order term in the asymptoticexpansion. We show that for any positive integer $L$, the second-order term isbounded between a term proportional to $-\ln_{(L)} n$ (where $\ln_{(L)}(\cdot)$is the $L$-fold nested logarithm function) and a term proportional to$+\sqrt{n\ln n}$ where $n$ is the blocklength. The lower bound on thesecond-order term shows that feedback does provide an improvement in themaximal achievable rate over the case where no feedback is available. In oursecond contribution, we establish the $\varepsilon$-capacity region for theAWGN multiple access channel (MAC) with feedback under the expected powerconstraint by combining ideas from hypothesis testing, information spectrumanalysis, Ozarow's coding scheme, and power control.

On Gaussian Channels with Feedback under Expected Power Constraints and with Non-Vanishing Error Probabilities