scholarly journals A Cross Time Slot Partial Interference Alignment Scheme in Two-Cell Relay Heterogeneous Networks

2019 ◽  
Vol 9 (4) ◽  
pp. 652 ◽  
Author(s):  
Cai Qin ◽  
Chaowei Wang ◽  
Du Pan ◽  
Weidong Wang ◽  
Yinghai Zhang
Keyword(s):  
Degrees Of Freedom ◽  
Time Slot ◽  
Interference Alignment ◽  
Rate Performance ◽  
Amplify And Forward ◽  
Feasibility Condition ◽  
Half Duplex ◽  
Partial Interference ◽  
Inter Cell Interference ◽  
Cell Edge User

The interference of a two-cell two-hop multi-input–multi-output (MIMO) heterogeneous network where the cell-center user (CCU) coexists with the cell-edge user (CEU) is complex to characterize and costly to suppress. In downlink, the CEU is assumed to be served by a half-duplex relay with amplify-and-forward mode. To suppress the intra-cell and inter-cell interference, a cross time slot partial interference alignment (TPIA) scheme, which aligns the interference terms generated in different sub-time slots to the same subspace, is proposed in this paper. Furthermore, the feasibility condition of antenna configuration is analyzed. Simulation results indicate that the TPIA scheme outperforms other existing conventional techniques in achievable sum degrees of freedom and sum-rate performance.

scholarly journals Outage Performance of Bidirectional Full-Duplex Amplify-and-Forward Relay Network with Transmit Antenna Selection and Maximal Ratio Combining

2018 ◽  
Vol 1 ◽  
pp. 62-69
Author(s):  
R. Rajesh ◽  
P. G. S. Velmurugan ◽  
S. J. Thiruvengadam ◽  
P. S. Mallick
Keyword(s):  
Antenna Selection ◽  
Relay Node ◽  
Maximal Ratio Combining ◽  
Full Duplex ◽  
Relay Network ◽  
Amplify And Forward ◽  
Transmit Antenna Selection ◽  
Outage Performance ◽  
Half Duplex ◽  
Af Relay

In this paper, a bidirectional full-duplex amplify- and-forward (AF) relay network with multiple antennas at source nodes is proposed. Assuming that the channel state information is known at the source nodes, transmit antenna selection and maximal ratio combining (MRC) are employed when source nodes transmit information to the relay node and receive information from the relay node respectively, in order to improve the overall signal-to-interference plus noise ratio (SINR). Analytical expressions are derived for tight upper bound SINR at the relay node and source nodes upon reception. Further, losed form expressions are also derived for end-to-end outage probability of the proposed bidirectional full-duplex AF relay network in the Nakagami-m fading channel environment. Although self-interference at the relay node limits the performance of the full-duplex network, the outage performance of the proposed network is better than that of conventional bidirectional full-duplex and half-duplex AF relay networks, due to the selection diversity gain in TAS and diversity and array gain in MRC.

scholarly journals Interference Alignment for Cognitive Radio Communications and Networks: A Survey

2019 ◽  
Vol 8 (4) ◽  
pp. 50 ◽  
Author(s):  
Yusuf Abdulkadir ◽  
Oluyomi Simpson ◽  
Yichuang Sun
Keyword(s):  
Cognitive Radio ◽  
Frequency Spectrum ◽  
Degrees Of Freedom ◽  
Signal To Noise Ratio ◽  
Interference Alignment ◽  
Radio Spectrum ◽  
High Signal ◽  
Radio Communications ◽  
Main Research ◽  
Transmission Strategy

Interference alignment (IA) is an innovative wireless transmission strategy that has shown to be a promising technique for achieving optimal capacity scaling of a multiuser interference channel at asymptotically high-signal-to-noise ratio (SNR). Transmitters exploit the availability of multiple signaling dimensions in order to align their mutual interference at the receivers. Most of the research has focused on developing algorithms for determining alignment solutions as well as proving interference alignment’s theoretical ability to achieve the maximum degrees of freedom in a wireless network. Cognitive radio, on the other hand, is a technique used to improve the utilization of the radio spectrum by opportunistically sensing and accessing unused licensed frequency spectrum, without causing harmful interference to the licensed users. With the increased deployment of wireless services, the possibility of detecting unused frequency spectrum becomes diminished. Thus, the concept of introducing interference alignment in cognitive radio has become a very attractive proposition. This paper provides a survey of the implementation of IA in cognitive radio under the main research paradigms, along with a summary and analysis of results under each system model.

On the Diversity-Multiplexing Tradeoff of Amplify-and-Forward Half-Duplex Relaying

2010 ◽  
Vol 58 (12) ◽  
pp. 3621-3630 ◽  
Author(s):  
H. Wicaksana ◽  
S. H. Ting ◽  
M. Motani ◽  
Y. L. Guan
Keyword(s):  
Amplify And Forward ◽  
Half Duplex ◽  
Diversity Multiplexing Tradeoff
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