In this paper, to enhance the robustness against link imbalance, a hybrid cooperative protocol is proposed for amplify-and-forward （AF） opportunistic cooperation, where opportunistic relaying and multi-hop cooperati...In this paper, to enhance the robustness against link imbalance, a hybrid cooperative protocol is proposed for amplify-and-forward （AF） opportunistic cooperation, where opportunistic relaying and multi-hop cooperation with relay ordering （RO） are dynamically selected to maximize the end to end signal-noise ratio （SNR）, and the power allocation coefficient is optimized under total power constraint accordingly. Furthermore, a suboptimum allocation scheme with low complexity is proposed by employing the upper bound of harmonic mean. Simulation results show that the proposed scheme outperforms conventional AF opportunistic cooperation in variety of line type topology. Moreover, the efficiency of the proposed suboptimum allocation is also validated in large SNR region.展开更多
This paper investigates the impacts of network coding （NC） on user fairness from the network perspective in multiple access channels. Firstly, simultaneous outage is exploited as the metric to evaluate user fairness...This paper investigates the impacts of network coding （NC） on user fairness from the network perspective in multiple access channels. Firstly, simultaneous outage is exploited as the metric to evaluate user fairness. To optimize it, a fairness-oriented physical layer NC scheme is proposed, in which users＇ signals are superimposed in specific calculated proportion at relay and then decoded by maximal ratio combination （MRC） and serial interference cancellation （SIC） at destination. Furthermore, the influence of power allocation coefficient error on simultaneous outage is also analyzed to reveal its correlation with user fairness. Simulation results indicate that the proposed scheme can supply approximately equal performance promotion for each cooperation-participated user and outperform those without fairness consideration in terms of the employed metric.展开更多
基金supported by the National Basic Research Program of China (2013CB329104)the National Natural Science Foundations of China (61071090, 61171093)+3 种基金the Postgraduate Innovation Programs of Jiangsu Scientific Research (CXZZ11_0388)the Natural Science Foundation Key Projects of Jiangsu (11KJA510001)the National Major Projects of Science and Technology (2011ZX03005-004-003)Jiangsu 973 Projects (BK2011027)
文摘In this paper, to enhance the robustness against link imbalance, a hybrid cooperative protocol is proposed for amplify-and-forward （AF） opportunistic cooperation, where opportunistic relaying and multi-hop cooperation with relay ordering （RO） are dynamically selected to maximize the end to end signal-noise ratio （SNR）, and the power allocation coefficient is optimized under total power constraint accordingly. Furthermore, a suboptimum allocation scheme with low complexity is proposed by employing the upper bound of harmonic mean. Simulation results show that the proposed scheme outperforms conventional AF opportunistic cooperation in variety of line type topology. Moreover, the efficiency of the proposed suboptimum allocation is also validated in large SNR region.
基金supported by the National Natural Science Foundations of China(61071090, 61171093)the Postgraduate Innovation Programs of Jiangsu Scientific Research(CXZZ11_0388,CXLX11_0404)+2 种基金the Jiangsu Province Natural Science Foundation Key Projects(11KJA510001)the National Science and Technology Key Projects(2011ZX03005-004-003)Jiangsu 973 Projects(BK2011027)
文摘This paper investigates the impacts of network coding （NC） on user fairness from the network perspective in multiple access channels. Firstly, simultaneous outage is exploited as the metric to evaluate user fairness. To optimize it, a fairness-oriented physical layer NC scheme is proposed, in which users＇ signals are superimposed in specific calculated proportion at relay and then decoded by maximal ratio combination （MRC） and serial interference cancellation （SIC） at destination. Furthermore, the influence of power allocation coefficient error on simultaneous outage is also analyzed to reveal its correlation with user fairness. Simulation results indicate that the proposed scheme can supply approximately equal performance promotion for each cooperation-participated user and outperform those without fairness consideration in terms of the employed metric.
