Differential network coding in wireless networks Telsiz aǧlarda farksal aǧ kodlamasi

Özdemir, Özgür
Yılmaz, Ali Özgür
In this paper a three-terminal communication scenario where two users exchange information by employing differential binary modulation and network coding via a relay is considered. The transmission is divided into three slots in time where the first and second slots are allocated to the transmission of differential encoded data of the users. After demodulation, the relay broadcasts the bit-wise XOR-ed and differential encoded packet to the users in the third slot. The optimum detector and a simplified decision algorithm are derived based on the maximum likelihood rule. The numerical results for Rayleigh fading show that both of the proposed algorithms provide full diversity order. The simulations also demonstrate that the proposed differential network coded transmission not only offers a sum-rate gain of up to 4/3 compared to classical bi-directional relaying with four communication slots but also provides better BER performance as the signal to noise ratio increases.


Performance Comparisons of Relaying Schemes in Bi-directional Demodulate-and-Forward Channels
ÖZDEMİR, ÖZGÜR; Yılmaz, Ali Özgür; Aktas, Emre (2012-04-04)
Bi-directional relaying (BDR) in which two users wish to exchange independent information in presence of a relay is one of the fundamental wireless network coding applications that attracted intense interests recently. In this paper, maximum likelihood (ML), cooperative maximal ratio combining (CMRC) and soft information relaying (SIR) schemes proposed to combat error propagation in wireless relay systems are applied to the BDR scenario with demodulate-and-forward protocol, which decreases system complexity...
Joint network-channel coding with repeat accumulate codes for wireless relay networks Röleli telsiz aǧlarda tekrarli biriktir kodlar ile bütünleşik aǧ-kanal kodlamasi
Özdemir, Özgür; Yılmaz, Ali Özgür (2009-10-29)
This paper presents two different repetition based joint network-channel coding schemes for a three-terminal communication system where two-users want to exchange information via a relay. The transmission is divided into three slots in time where the first and second slots are allocated to the RA (Repeat Accumulate) encoded data of the users. In the first scheme we propose, the relay decodes the received signals and transmits a bit-wise XOR-ed packet using RA coding in the third slot. In the second scheme, ...
Demir, Özlem Tuğfe; Tuncer, Temel Engin (2015-09-04)
In this paper, simultaneous wireless information and power transfer (SWIPT) concept is introduced for multi group multicast beamforming. Each user has a single antenna and a power splitter which divides the radio frequency (RF) signal into two for both information decoding and energy harvesting. The aim is to minimize the total transmission power at the base station while satisfying both signal-to-interference-plus- noise-ratio (SINR) and harvested power constraints at each user. Unlike unicast and certain ...
Diversity Analysis of Hierarchical Modulation in Wireless Relay Networks
Yalcyn, Ahmet Zahid; Yüksel Turgut, Ayşe Melda (2014-07-01)
In communication systems, hierarchical modulation is used to increase system robustness and to send different information flows simultaneously. However, when used in cooperative communication systems, hierarchical modulation is prone to error propagation, which is the most important problem that prevents the achievement of full diversity gains. Depending on the signal-to-noise ratio between the source and the relay, threshold digital relaying can be used to mitigate error propagation. Mitigating error propa...
Practical Methods for Wireless Network Coding With Multiple Unicast Transmissions
Aktas, Tugcan; Yılmaz, Ali Özgür; AKTAŞ, EMRE (2013-03-01)
We propose a simple yet effective wireless network coding and decoding technique for a multiple unicast network. It utilizes spatial diversity through cooperation between nodes which carry out distributed encoding operations dictated by generator matrices of linear block codes. In order to exemplify the technique, we make use of greedy codes over the binary field and show that the arbitrary diversity orders can be flexibly assigned to nodes. Furthermore, we present the optimal detection rule for the given m...
Citation Formats
Ö. Özdemir and A. Ö. Yılmaz, “Differential network coding in wireless networks Telsiz aǧlarda farksal aǧ kodlamasi,” 2009, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/57335.