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 Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Classical, i.e. non-quantum, communications include configurations withmultiple-input multiple-output (MIMO) channels. Some associated signalprocessing tasks consider these channels in a symmetric way, i.e. by assigningthe same role to all channel inputs, and similarly to all channel outputs.These tasks especially include channel identification/estimation and channelequalization, tightly connected with source separation. Their most challengingversion is the blind one, i.e. when the receivers have (almost) no priorknowledge about the emitted signals. Other signal processing tasks considerclassical communication channels in an asymmetric way. This especially includesthe situation when data are sent by Emitter 1 to Receiver 1 through a mainchannel, and an "intruder" (including Receiver 2) interferes with that channelso as to extract information, thus performing so-called eavesdropping, whileReceiver 1 may aim at detecting that intrusion. Part of the above processingtasks have been extended to quantum channels, including those that have severalquantum bits (qubits) at their input and output. For such quantum channels,beyond previously reported work for symmetric scenarios, we here addressasymmetric (blind and non-blind) ones, with emphasis on intrusion detection andadditional comments about eavesdropping. To develop fundamental concepts, wefirst consider channels with exchange coupling as a toy model. We especiallyuse the general quantum information processing framework that we recentlydeveloped, to derive new attractive intrusion detection methods based on asingle preparation of each state. Finally, we discuss how the proposed methodsmight be extended, beyond the specific class of channels analyzed here.

Statistical intrusion detection and eavesdropping in quantum channels with coupling: Multiple-preparation and single-preparation methods