Elektrik - Elektronik Mühendisliği Bölümü Koleksiyonu

Permanent URI for this collectionhttps://hdl.handle.net/20.500.12469/47

Browse

Browsing Elektrik - Elektronik Mühendisliği Bölümü Koleksiyonu by Journal "2012 20th Signal Processing and Communications Applications Conference (SIU)"

Filter results by typing the first few letters
Now showing 1 - 3 of 3
  • Thumbnail Image
    Conference Object
    Citation - Scopus: 2
    The Effect Of Secondary User Locations On The Cooperative Detection Performance [iki?nci?l Kullanıcı Konumlarının İ?şbi?rli?kli? Algılama Yöntemi? Performansına Etki?si?]
    (IEEE, 2012) Çatak, Evren; Erküçük, Serhat
    In conventional cooperative detection a fusion center decides on the presence or absence of the primary user by gathering all the information from secondary users and conveys this decision to all users. This approach does not take into account the locations of the secondary users where a user far from the primary user may also have to keep silent. In a recent work there has been a new detection method based on combining received signals from more than two users obtaining decision tables and deciding individually for each user. While the proposed method showed promising results for the secondary users the effect of the user distribution was not investigated. In this study we consider the effect of secondary user location and number on the detection performance. We show that (i) the evaluation of the conventional method in the proposed method is not accurate and (ii) depending on the user location the detection performance may be better or worse compared to the conventional detection. © 2012 IEEE.
  • Thumbnail Image
    Conference Object
    Routing Performance Analysis Of Opportunistic Networks With Flooding And Partial Flooding Methods [fırsatçı A?larda Taşırma ve Kısmi Taşırma Yöntemleriyle Yönlendirme Performans Analizi]
    (IEEE, 2012) Erdoğan, Mustafa; Günel, Kadir; Koç, Tuğba; Sökün, Hamza Ümit; Dağ, Tamer
    Opportunistic networks is one of the fast developing research areas in mobile communications. Under opportunistic networks mobile nodes try to communicate with other nodes without any prior information and knowledge about the network topology. Furthermore network topologies are dynamic and can rapidly change. In addition communication under opportunistic networks is erratic thus routes between a source node and a destination node sometimes might not exist. These issues would make classical routing approaches insufficient and unusable for opportunistic networks. In this paper two routing approaches for opportunistic networks are proposed. The first approach is flooding. Under flooding it is possible to reach a destination node with the minimum number of hops and minimum delay but with maximum network traffic. The second approach is selective flooding.The aim of selective flooding is to decrease network traffic by randomly selecting neighbor nodes and routing traffic through them. This paper explains these two approaches and compares their performance through various simulations. © 2012 IEEE.
  • Thumbnail Image
    Conference Object
    Sparse Underwater Acoustic Channel Estimation İn Colored Gaussian Noise [renkli? Gauss Gürültülü Seyrek Sualtı Akusti?k Kanalların Kestirimi]
    (IEEE, 2012) Erdoğan, Mustafa; Şenol, Habib; Panayırcı, Erdal; Uysal, Murat
    Cooperative underwater acoustic communication systems come into prominence in recent years. Since underwater channels are sparse and additive noise entering the system is colored Gaussian noise. Therefore it is very difficult to estimate the underwater channels and theoretically makes it interesting. In this study the transmission from source to the target recipient is realized by means of a relay system. Orthogonal frequency division multiplexing (OFDM)-based channel estimation problem is solved by using the matching pursuit (MP) algorithm and we obtained excellent error performance.