Cooperative coded partial retransmission scheme based on link adaptive technology

在协作编码部分重传(COdEd PArTIAl rETrAnSMISSIOn,CPr)机制的基础上,引入链路自适应技术,通过在中继节点获取链路状态信息后,选择调制编码模式,实现自适应协作传输。仿真结果表明,在不降低系统吞吐量的情况下,改善了bEr性能,在吞吐量为0.19时,自适应调制的CPr机制相对于直接传输的CPr增益约为4.5 db。在bEr为10-3时,自适应调制的CPr协议相对于非自适应CPr协议增益约为2 db。In this paper,the cooperative Coded Partial(CPR) Retransmission scheme based on link adaptive technique is proposed.Utilizing the link state information at the relay node,the optimized-modulation and code mode of relay node is chosen.The simulated results show that Bit Error Rate(BER) performance of the proposed system is improved without sacrificing the system throughput.The BER of the proposed scheme has about 4.5 dB gains compared with that of the direct transmission at throughput of 0.19,Moreover,the proposed scheme obtains about 2 dB compared with the non-adaptive scheme at BER of 10-3.重庆市科委攻关项目(CSTC;2009AA2037)---

双圆弧柔轮齿形参数对谐波齿轮传动共轭特性的影响

谐波齿轮传动过程中，双圆弧齿廓可有效避免尖点啮合现象。为进一步优化双圆弧齿廓，提高谐波齿轮传动装置的性能，基于改进运动学法的精确共轭理论，采用Matlab编程计算的方法，对比分析了柔轮齿廓中主要参数的变化对共轭区域和共轭齿廓的影响。分析结果表明，柔轮轮齿凸齿廓圆弧半径、凹齿廓圆弧半径和径向变形量对共轭齿廓形状影响显著；而公切线倾角、公切线长度对共轭区间和共轭齿廓弧长影响较明显，合理选用柔轮齿廓参数可有效提升谐波齿轮装置的传动性能

RAPD分析野生和养殖太湖秀丽白虾的遗传多样性

<正>秀丽白虾(Exopalaemon modestus)广泛分布于我国淡水湖泊及河流中,南北均产。在太湖的虾类组成中,秀丽白虾占50%以上。近年来,由于水质污染和过度捕捞等原因,太湖秀丽白虾的繁衍、生存受到了很大威胁,白虾种质资源保护

Determination of the number of ψ(3686) events taken at BESIII

The number of ψ(3686) events collected by the BESIII detector during the 2021 run period is determined to be (2259.3±11.1)×106 by counting inclusive ψ(3686) hadronic events. The uncertainty is systematic and the statistical uncertainty is negligible. Meanwhile, the numbers of ψ(3686) events collected during the 2009 and 2012 run periods are updated to be (107.7±0.6)×106 and (345.4±2.6)×106, respectively. Both numbers are consistent with the previous measurements within one standard deviation. The total number of ψ(3686) events in the three data samples is (2712.4±14.3)×10^