Cooperative relaying schemes for narrow-band frequency hopping wireless ad hoc networks

Yenihayat, Güven
Onat, Furuzan Atay
Kolaǧasioǧlu, Ertuǧrul
Yılmaz, Ali Özgür
Cooperative relaying is a promising technique for improving the performance of weak communication links in wireless networks by exploiting spatial diversity induced by relay transmissions. This paper considers cooperative relaying schemes for a narrow- band frequency hopping system. A novel hybrid relaying scheme called opportunistic hybrid relaying, which is specifically designed for this system, is presented. Unlike most relaying schemes in the literature, opportunistic hybrid relaying uses bandwidth efficiently by allowing the relays to transmit in non-orthogonal channels without any considerable coordination overhead among the relays. A joint channel estimation and data detection scheme is considered to be used at the destination to combine relay signals. It is shown that this scheme compares favorably to similar relaying schemes in the literature in terms of average success rate.


Network density estimators and density-aware wireless networks
Eroğlu, Alperen; Onur, Ertan; Department of Computer Engineering (2020-11)
New network architectures and communication technologies continue to emerge to meet rapidly increasing and changing user demands requiring continuous connectivity and high data rate transmissions. These ubiquitous infrastructures result in a paradigm shift in mobile communications with the advent of mobile robots equipped with sensors, unmanned aerial vehicles, and mobile small-cells, which makes the future networks highly dynamic. This dynamism poses unpredictable variations in the network density causing ...
Joint Mitigation of IQ Imbalance and Power Amplifier Impairments by Real Valued Time Delay Neural Networks
Yeşil, Soner; Gürtunca, Burak; Yılmaz, Ali Özgür (2019-08-22)
This paper represents a neural network based joint mitigation of the IQ imbalance and power amplifier nonlinearities that cause degradation in the transmit signal quality of the wireless communication systems. A Real Valued Time Delay Neural Network architecture for this purpose has been verified on a hardware including cascaded NXP-MD8IC925 and NXPBLF8G10LS power amplifier components performing a total of 46dB gain. The test setup has been controlled over MATLAB in order to have a closed loop adaptive digi...
Diversity Analysis of Hierarchical Modulation in Cooperative Communication
Yalcin, Ahmet Zahid; Yüksel Turgut, Ayşe Melda (2014-01-01)
In cooperative communication systems, hierarchical modulation is used to increase systems robustness and to send different information flows simultaneously. In cooperative communication systems which use hierarchical modulation, error propagation is the most important problem that prevents achieving full diversity gain. Thresholds that depend on the signal to noise ratio (SNR) value between the source and the relay can be used to mitigate error propagation. If the instantaneous SNR between the source and th...
Parallel decodable channel coding implemented on a MIMO testbed
Aktaş, Tuğcan; Yılmaz, Ali Özgür; Department of Electrical and Electronics Engineering (2007)
This thesis considers the real-time implementation phases of a multiple-input multiple-output (MIMO) wireless communication system. The parts which are related to the implementation detail the blocks realized on a field programmable gate array (FPGA) board and define the connections between these blocks and typical radio frequency front-end modules assisting the wireless communication. Two sides of the implemented communication testbed are discussed separately as the transmitter and the receiver parts. In a...
Optimizing the Performance of Rule-Based Fuzzy Routing Algorithms in Wireless Sensor Networks
Sert, Seyyit Alper; Yazıcı, Adnan (2019-06-01)
Effective data routing is one of the crucial themes for energy-efficient communication in wireless sensor networks (WSN). In the WSN research domain, fuzzy approaches are in most cases superior to well-defined methodologies, especially where boundaries between clusters are unclear. For this reason, a significant number of studies have recently proposed fuzzy-based solutions for the problems encountered in WSNs. Rule-based fuzzy systems are part of these widespread fuzzy-based solutions that often involve so...
Citation Formats
G. Yenihayat, F. A. Onat, E. Kolaǧasioǧlu, and A. Ö. Yılmaz, “Cooperative relaying schemes for narrow-band frequency hopping wireless ad hoc networks,” 2011, Accessed: 00, 2020. [Online]. Available: