1 Ocak 2024 Dergi makalesi Açık Erişim

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

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{
  "@context": "https://schema.org/", 
  "@id": 280643, 
  "@type": "ScholarlyArticle", 
  "creator": [
    {
      "@type": "Person", 
      "affiliation": "Bilkent Univ, Dept Elect & Elect Engn, TR-06800 Ankara, Turkiye", 
      "name": "Ahmadi, Mohammad Javad"
    }, 
    {
      "@type": "Person", 
      "affiliation": "Bilkent Univ, Dept Elect & Elect Engn, TR-06800 Ankara, Turkiye", 
      "name": "Kazemi, Mohammad"
    }, 
    {
      "@type": "Person", 
      "affiliation": "Bilkent Univ, Dept Elect & Elect Engn, TR-06800 Ankara, Turkiye", 
      "name": "Duman, Tolga M."
    }
  ], 
  "datePublished": "2024-01-01", 
  "description": "<p>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.</p>", 
  "headline": "Unsourced Random Access Using Multiple Stages of Orthogonal Pilots: MIMO and Single-Antenna Structures", 
  "identifier": 280643, 
  "image": "https://aperta.ulakbim.gov.tr/static/img/logo/aperta_logo_with_icon.svg", 
  "license": "http://www.opendefinition.org/licenses/cc-by", 
  "name": "Unsourced Random Access Using Multiple Stages of Orthogonal Pilots: MIMO and Single-Antenna Structures", 
  "url": "https://aperta.ulakbim.gov.tr/record/280643"
}