1 Ocak 2024 Dergi makalesi Açık Erişim

Ahmadi, Mohammad Javad; Kazemi, Mohammad; Duman, Tolga M.

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  <dc:creator>Ahmadi, Mohammad Javad</dc:creator>
  <dc:creator>Kazemi, Mohammad</dc:creator>
  <dc:creator>Duman, Tolga M.</dc:creator>
  <dc:date>2024-01-01</dc:date>
  <dc:description>We study the problem of unsourced random access (URA) over Rayleigh block-fading channels with a receiver equipped with multiple antennas. We propose a slotted structure with multiple stages of orthogonal pilots, each of which is randomly picked from a codebook. In the proposed signaling structure, each user encodes its message using a polar code and appends it to the selected pilot sequences to construct its transmitted signal. Accordingly, the transmitted signal is composed of multiple orthogonal pilot parts and a polar-coded part, which is sent through a randomly selected slot. The performance of the proposed scheme is further improved by randomly dividing users into different groups each having a unique interleaver-power pair. We also apply the idea of multiple stages of orthogonal pilots to the case of a single receive antenna. In all the set-ups, we use an iterative approach for decoding the transmitted messages along with a suitable successive interference cancellation technique. The use of orthogonal pilots and the slotted structure lead to improved accuracy and reduced computational complexity in the proposed set-ups, and make the implementation with short blocklengths more viable. Performance of the proposed set-ups is illustrated via extensive simulation results which show that the proposed set-ups with multiple antennas perform better than the existing MIMO URA solutions for both short and large blocklengths, and that the proposed single-antenna set-ups are superior to the existing single-antenna URA schemes.</dc:description>
  <dc:identifier>https://aperta.ulakbim.gov.trrecord/280643</dc:identifier>
  <dc:identifier>oai:aperta.ulakbim.gov.tr:280643</dc:identifier>
  <dc:rights>info:eu-repo/semantics/openAccess</dc:rights>
  <dc:rights>http://www.opendefinition.org/licenses/cc-by</dc:rights>
  <dc:source>IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS 23(2) 13</dc:source>
  <dc:title>Unsourced Random Access Using Multiple Stages of Orthogonal Pilots: MIMO and Single-Antenna Structures</dc:title>
  <dc:type>info:eu-repo/semantics/article</dc:type>
  <dc:type>publication-article</dc:type>
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