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

Prior studies on intelligent reflecting surface (IRS) have mostly consideredwireless communication systems aided by a single passive IRS, which, however,has limited control over wireless propagation environment and suffers severeproduct-distance path-loss. To address these issues, we propose in this paper anew multi-active multi-passive (MAMP)-IRS aided wireless communication system,where a number of active and passive IRSs are deployed to assist the downlinkcommunication in complex environment, by establishing a multi-hop reflectionpath across active and passive IRSs. An optimization problem is formulated tomaximize the achievable rate of a typical user by designing theactive-and-passive IRS routing path as well as the joint beamforming of the BSand selected active/passive IRSs. To draw useful insights into the optimaldesign, we first consider a special case of the single-active multi-passive(SAMP)-IRS aided system. For this case, we propose an efficient algorithm toobtain its optimal solution by first optimizing the joint beamforming given anySAMP-IRS routing path, and then optimizing the routing path by using a new pathdecomposition method and graph theory. Next, for the general MAMP-IRS aidedsystem, we show that its challenging beam routing optimization problem can beefficiently solved by a new two-phase approach. Its key idea is to firstoptimize the inner passive-IRS beam routing between each two active IRSs foreffective channel power gain maximization, followed by an outer active-IRS beamrouting optimization for rate maximization. Last, numerical results areprovided to demonstrate the effectiveness of the proposed MAMP-IRS beam routingscheme.

Multi-Active Multi-Passive (MAMP)-IRS Aided Wireless Communication: A Multi-Hop Beam Routing Design