Electrical - Electronic Engineering / Elektrik - Elektronik Mühendisliği

Permanent URI for this collectionhttps://hdl.handle.net/11147/11

Browse

Filters

2018 - 20192

Settings

Author: search.filters.author.Karabulut Kurt, GüneşWoS Q: search.filters.wosQuartile.Q3

Search Results

Now showing 1 - 2 of 2
  • Article
    Citation - WoS: 3
    Citation - Scopus: 3
    Secure Multiuser Mimo Communication Systems With Imperfect Channel State Information
    (Elsevier Ltd., 2019) Özbek, Berna; Özdoğan Şenol, Özgecan; Karabulut Kurt, Güneş
    In this paper, we propose a secure wireless communications system through a multiple input multiple output (MIMO) channel which includes a multiple antenna base station and multiple single antenna legitimate users that are overheard by a multiple antenna eavesdropper. By assuming that the eavesdropper's channel is unknown by the base station, an artificial noise beamforming is used to prevent this eavesdropper to decode legitimate users' message in the downlink. Additionally, the base station has only imperfect channel state information (CSI) of legitimate users which is the practically relevant case. Under the condition of imperfect CSI, a noise leakage on legitimate users' signal is occurred and it degrades the achievable average secrecy sum rate. In order to reduce this noise leakage, the semi-orthogonal selection having a rotated codebook is proposed to establish a secure communications link. We demonstrate the average secrecy sum rate results of the proposed algorithm for secure multiuser MIMO systems under imperfect CSI through extensive simulation results. (c) 2019 Elsevier B.V. All rights reserved.
  • Article
    Citation - WoS: 1
    Citation - Scopus: 2
    Secure Multiuser Miso Communication Systems With Limited Feedback Link
    (Springer Verlag, 2018) Özbek, Berna; Özdoğan Şenol, Özgecan; Karabulut Kurt, Güneş
    Physical layer security is one of the promising techniques for the security of next-generation wireless systems. In this paper, we analyze the impact of the limited feedback link on the secrecy capacity for a system which includes a base station with multiple antennas, a single legitimate user selected from multiple active ones and multiple eavesdroppers. We propose to design a limited feedback link by reducing the feedback load and quantizing the channel state information (CSI) of legitimate users to establish a secure communication system. The feedback load is decreased with a self discrimination criterion at the legitimate users’ side while keeping the secrecy capacity constant. The best legitimate user is selected based on the quantized CSI through a limited feedback link. We also analyze the impact of CSI of eavesdroppers, which information may or may not be available at transmitter. In practical cases where eavesdroppers are passive and their location is not known by the transmitter, an artificial noise is used to disrupt their reception. When the CSI of eavesdroppers is known, the generalized singular value decomposition is applied. We illustrate the performance results of the proposed limited feedback link through the availability of CSI of eavesdroppers at the transmitter.