The airflow in the reed groove of the air jet loom for the weft insertion includes the jet stream from the relay nozzle, the back leak stream from the reed, and the diffusion stream from the open side. The air velocit...The airflow in the reed groove of the air jet loom for the weft insertion includes the jet stream from the relay nozzle, the back leak stream from the reed, and the diffusion stream from the open side. The air velocity in the reed groove can be measured to analyze the influence of process parameters during the weft insertion. The relation between the air velocity and the relay nozzle distance, the jet angle or the supply pressure of the relay nozzle can be studied. In this paper, the pitot tube is applied to measure the air velocity in reed groove by the instrument designed. And the results indicate that the air velocity fluctuation in the reed groove is strong, and can drop from 150 m·s-1 to 80 m·s-1 drastically.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
A Gaussian channel with additive interference that is causally known to the transmitter is called a Dirty-Tape Channel(DTC).In this paper,we consider a state-dependent dirty-tape Gaussian relay channel with orthogonal...A Gaussian channel with additive interference that is causally known to the transmitter is called a Dirty-Tape Channel(DTC).In this paper,we consider a state-dependent dirty-tape Gaussian relay channel with orthogonal channels from the source to the relay and from the source and relay to the destination.The orthogonal channels are corrupted by two independent additive interferences causally known to both the source and relay.The lower and upper bounds of the channel capacity are established.The lower bound is obtained by employing superposition coding at the source,Partial Decode-and-Forward(PDF)relaying at the relay,and a strategy similar to that used by Shannon at the source and relay.The explicit capacity is characterised when the power of the relay is sufficiently large.Finally,several numerical examples are provided to illustrate the impact of additive interferences and the role of the relay in information transmission and in removing the interference.展开更多
Joint sub-optimization of cooperative relays in Multiple-Input and Multiple-Output (MIMO) multiple relays aided communication system is discussed in this paper. Because the instantaneous channel state information of a...Joint sub-optimization of cooperative relays in Multiple-Input and Multiple-Output (MIMO) multiple relays aided communication system is discussed in this paper. Because the instantaneous channel state information of all source-relay channels and all relay-user channels is difficult to get at each relay node, an unjoined solution is designed according to the channel state information of that relay only. Then a multi-user loading algorithm is proposed to utilize the space diversity through multi-relay transmission. The simulation results show that with the newly proposed multi-user loading algorithm, the unjoined solution can achieve better system performance comparing with joint one in low SNR. However, the complexity of the former is much lower, for only partial CSI is needed.展开更多
文摘The airflow in the reed groove of the air jet loom for the weft insertion includes the jet stream from the relay nozzle, the back leak stream from the reed, and the diffusion stream from the open side. The air velocity in the reed groove can be measured to analyze the influence of process parameters during the weft insertion. The relation between the air velocity and the relay nozzle distance, the jet angle or the supply pressure of the relay nozzle can be studied. In this paper, the pitot tube is applied to measure the air velocity in reed groove by the instrument designed. And the results indicate that the air velocity fluctuation in the reed groove is strong, and can drop from 150 m·s-1 to 80 m·s-1 drastically.
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.
基金supported by the Fundamental Research Funds for the Central Universities under Grants No.2013B08214,No2009B32114the National Natural Science Foundation of China under Grants No.61271232,No.60972045,No.61071089+1 种基金the Open Research Fund of National Mobile Communications Research Laboratory,Southeast University under Grant No.2012D05the University Postgraduate Research and Innovation Project in Jiangsu Province under Grant No.CXZZ11_0395
文摘A Gaussian channel with additive interference that is causally known to the transmitter is called a Dirty-Tape Channel(DTC).In this paper,we consider a state-dependent dirty-tape Gaussian relay channel with orthogonal channels from the source to the relay and from the source and relay to the destination.The orthogonal channels are corrupted by two independent additive interferences causally known to both the source and relay.The lower and upper bounds of the channel capacity are established.The lower bound is obtained by employing superposition coding at the source,Partial Decode-and-Forward(PDF)relaying at the relay,and a strategy similar to that used by Shannon at the source and relay.The explicit capacity is characterised when the power of the relay is sufficiently large.Finally,several numerical examples are provided to illustrate the impact of additive interferences and the role of the relay in information transmission and in removing the interference.
基金Supported by National Basic Research Program of China (2007CB310603)National Natural Science Foundation of China (No.60672093)National High Technology Project of China (2007AA01Z262)
文摘Joint sub-optimization of cooperative relays in Multiple-Input and Multiple-Output (MIMO) multiple relays aided communication system is discussed in this paper. Because the instantaneous channel state information of all source-relay channels and all relay-user channels is difficult to get at each relay node, an unjoined solution is designed according to the channel state information of that relay only. Then a multi-user loading algorithm is proposed to utilize the space diversity through multi-relay transmission. The simulation results show that with the newly proposed multi-user loading algorithm, the unjoined solution can achieve better system performance comparing with joint one in low SNR. However, the complexity of the former is much lower, for only partial CSI is needed.
