In this paper, we study the performance of physical-layer network coding in asymmetric two-way relay channels using four different cases having different poor channels:phase asymmetry, downlink asymmetry, uplink asymm...In this paper, we study the performance of physical-layer network coding in asymmetric two-way relay channels using four different cases having different poor channels:phase asymmetry, downlink asymmetry, uplink asymmetry and node asymmetry. The decision and mapping rule for symmetric and asymmetric cases are studied. The performance in terms of bit error rate for each case will be studied and analysed by computer simulation. Analytical and simulation results show that uplink asymmetry is the worst case;intra-phase asymmetry and unreliable uplink channels will more severely affect the performance degradation, which is caused by channel asymmetry.展开更多
We consider a two-way relay network where the Amplify-and-Forward (AF) protocol is adopted by all relays in this paper.The network consists of two multi-antenna source nodes and multiple distributed single-antenna rel...We consider a two-way relay network where the Amplify-and-Forward (AF) protocol is adopted by all relays in this paper.The network consists of two multi-antenna source nodes and multiple distributed single-antenna relays.Two opportunistic relaying schemes are proposed to efficiently utilize the antennas of the source nodes and the relay nodes.In the first scheme,the best relay is selected out by a max-min-max criterion before transmitting.After that,at each source,only the antenna with the largest channel gain between itself and the best relay is activated to transmit and receive signals with full power.In the second scheme,assisted by the best relay which is selected by the typical max-min criterion,both source nodes use all their antennas to exchange data,and match filter beamforming techniques are employed at both source nodes.Further analyses show that all schemes can achieve the full diversity order,and the conclusions are not only mathematically demonstrated but numerically illustrated.System performance comparisons are carried out by numerical methods in terms of rate sum and outage probability,respectively.The beamforming assisted scheme can be found to be superior to the antenna selection scheme when accurate Channel State Information (CSI) is available at the transmitters.Otherwise,the latter is very suitable.展开更多
基金supported by the National Natural Science Foundation of China under Grant No.61101248the Equipment Advance Research Projectof"Twelfth Five-Year"Plan under Grant No.51306040202And this work has been performed in the Project"Advanced Communication Research Program(ACRP)"supported by the Directorate of Research and Development,Defense Science and Technology Agency,Singapore under Grant No.DSOCL04020
文摘In this paper, we study the performance of physical-layer network coding in asymmetric two-way relay channels using four different cases having different poor channels:phase asymmetry, downlink asymmetry, uplink asymmetry and node asymmetry. The decision and mapping rule for symmetric and asymmetric cases are studied. The performance in terms of bit error rate for each case will be studied and analysed by computer simulation. Analytical and simulation results show that uplink asymmetry is the worst case;intra-phase asymmetry and unreliable uplink channels will more severely affect the performance degradation, which is caused by channel asymmetry.
基金supported by the National Natural Science Foundation of China under Grant No.60902092
文摘We consider a two-way relay network where the Amplify-and-Forward (AF) protocol is adopted by all relays in this paper.The network consists of two multi-antenna source nodes and multiple distributed single-antenna relays.Two opportunistic relaying schemes are proposed to efficiently utilize the antennas of the source nodes and the relay nodes.In the first scheme,the best relay is selected out by a max-min-max criterion before transmitting.After that,at each source,only the antenna with the largest channel gain between itself and the best relay is activated to transmit and receive signals with full power.In the second scheme,assisted by the best relay which is selected by the typical max-min criterion,both source nodes use all their antennas to exchange data,and match filter beamforming techniques are employed at both source nodes.Further analyses show that all schemes can achieve the full diversity order,and the conclusions are not only mathematically demonstrated but numerically illustrated.System performance comparisons are carried out by numerical methods in terms of rate sum and outage probability,respectively.The beamforming assisted scheme can be found to be superior to the antenna selection scheme when accurate Channel State Information (CSI) is available at the transmitters.Otherwise,the latter is very suitable.
