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In this study a new jammer design for orthogonal frequency division multiplexing (OFDM) based systems is in- troduced. We present three new vulnerability attack scenarios based on chirp signals. These are the conventional chirp attack, the cyclic prefix chirp attack and the pilot tone chirp attack. Bit error rate (BER) performances are investigated in presence of chirp based attacks. It is shown that...
We designed and implemented single carrier-frequency domain multiple access (SC-FDMA) based system by using software defined radio (SDR) nodes. We aimed to investigate the performance of an LTE system against smart jamming attacks, which target synchronization and channel estimation processes. Cyclic prefix (CP) based jamming attacks and pilot jamming attacks are evaluated and observed for both uplink...
In this paper, cyclic autocorrelation function (CAF) is used for signal type identification. Orthogonal frequency division multiple access (OFDMA) signals with different cyclic prefix lengths are generated by using software defined radio nodes. According to test results, by using the OFDMA frame structure, it is possible to distinguished between OFDMA signals, hence signal parameters can be blindly...
Source direction of arrival (DoA) or angle of arrival (AoA) estimation is one of the vital problems in many wireless communication applications such as radar, radio astronomy, sonar and navigation. The resolution of a source direction of arrival estimation can be improved by an uniform linear array (ULA) system with innovative signal processing techniques. Super resolution techniques take the advantage...
Benefits of network coding towards enhancing communication quality, both in terms of robustness or data transmission rates, make it a significant candidate as a future networking technology. Conventionally, network coding is mostly used in wired infrastructures, where transmission errors between nodes are negligible. Capturing the provided benefits of network coding via straightforward extension from...
Diversifying and developing wireless communication technologies give rise to many problems. Two of the main problems are efficient usage of frequency spectrum and security. The techniques that are used to solve such problems strictly need detection of signal types. When unwanted symbols are detected, these signal sources can be stopped or their interfering components can be canceled from the information...
In this study, real-time software defined radio implementation of the point to point multiple input multiple output (MIMO) orthogonal frequency division multiplexing (OFDM) system using pre-fast Fourier transform (pre-FFT) beamforming technique in both the transmitter and the receiver is done for the first time in the literature. By taking benefit of the MIMO system's spatial multiplexing property,...
This paper presents measurement results collected from an IEEE 802.11ac based wireless test-bed to experimentally demonstrate how 802.11ac affects the throughput performance of a WLAN with different Transmission Control Protocol (TCP) variants implemented in Linux kernel. We compare the performance of 802.11ac with 802.11n for both single and multi-hop transmissions in a wireless mesh network (WMN)...
The effect of two important MAC parameters on performance of IEEE 802.11ac and 802.11n based wireless local area networks (WLANs) have been investigated experimentally. In the first experiment set-up, effects of Request to Send/Clear to Send (RTS/CTS) packets on throughput performance are observed according to the number of hops. In the second set-up, the impact of A-MPDU technique on throughput performance...
OFDM technique has wide usage in modern communication systems, it can offer efficient use of frequency spectrum and high service quality for users. In literature, there are some software defined radio implementations of OFDM technique. OFDMA technique that can deliver advantages of OFDM technique to multi-user and dynamic based systems is more important for modern communications systems. In this study,...
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