Now showing items 1-7 of 7

  • Bayesian learning for cellular neural networks 

    Authors:Ozer, Metin
    Publisher and Date:(Kadir Has University, 2013)
    Cellular Neural Networks have been an active research eld since their introduction in the late 80s. Several training algorithms are proposed since then. All have their advantages and disadvantages. Most of them uses deterministic methods to acquire the network parameters. in this thesis a new training method is proposed for Cellular Neural Networks and Discrete-Time Cellular Neural Networks are used for implemented applications. This new method is a probabilistic method. Maximum A Posteriori ...

  • Detection of interdependent multiband systems for cognitive radios and ultra-wideband systems 

    Authors:Yılmaz, Burak
    Publisher and Date:(Kadir Has University, 2012)
    As a result of advances in the wireless technology new systems have been proposed and hence more frequency bands are occupied in the spectrum. Therefore the number ofavailable frequency bands for future wireless communication systems is decreasing and alternative communication technologies have appeared in recent years. These are cognitive radio and ultra wideband systems which use the spectrum more efficiently. -- Abstract'dan.

  • Femtocell design for data communications in mobile networks 

    Authors:Cogalan, Tezcan
    Publisher and Date:(Kadir Has University, 2013)
    in this thesis game theoretic utility-based adaptive power control algorithm for uplink of femtocell networks is performed for mitigation of interference in two different ways. The first one is allocation of femtocell interference threshold in randomly activated femtocell base stations in a known macrocell coverage area and the second one is adaptation of the power of the femtocell users for mitigating total interference from femtocell users at the macrocell base station. Accordingly we consider ...

  • New channel estimation techniques for cooperative underwater acoustic OFDM systems 

    Authors:Mustafa, Erdoğan
    Publisher and Date:
    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 it is very difficult to estimate the underwater channels and theoretically makes it interesting. in the first part of the thesis 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 ...

  • Practical implementation of combinational cooperative detection method 

    Authors:Çatak, Evren
    Publisher and Date:(Kadir Has University, 2012)
    in conventional cooperative detection a fusion center decides on the presence or theabsence of the primary user by gathering all the information from the secondaryusers (SUs) and conveys this decision to all users. This approach does not take intoaccount the locations of the SUs where a user far from the primary user (PU) mayalso have to keep silent. An alternative method referred to as the combinationalcooperative detection method in this study was recently proposed to solve thisproblem. This ...

  • Primary user detection in Ultrawide-band based wireless sensor networks 

    Authors:Sabucu, Yağmur
    Publisher and Date:(Kadir Has University, 2013)
    in this thesis ultra-wideband (UWB) based wireless sensor networks (WSNs) are considered for the detection of a primary user. Different from earlier works (i) both uplink and downlink information of the primary user are assessed for the primary user detection and (ii) iEEE 802.15.4a standard is considered for the implementation of each secondary user. Specifically the worked focused on the comparison of the two iEEE 802.15.4a based signalling namely binary pulse position modulation (BPPM) and ...

  • Scattering transfer matrix factorization based synthesis of resistively terminated LC ladder networks 

    Authors:Aydoǧar, Zafer
    Publisher and Date:(Kadir Has University, 2011)
    Bu yüksek lisans tezimde, direnç ile sonlandırılmış LC merdiven devrelerin sentezi için algoritmalr önerilmiştir. Bu algoritmalar saçılma transfer matrisi faktorizasyonuna dayanır. Alçak-geçiren, yüksek-geçiren, band-geçiren ve band-söndüren durumlar için dört algoritma geliştirilmiştir. Algoritmaların temelinde şu fikir yer almaktadır: İlk olarak, verilen saçılma tranfer matrisi kullanılarak bir sabit hesaplanır. Bu sabitin değerine göre çekilecek elemanın tipine karar verilir, daha sonra verilen ...