TDRSS接收机码分多址干扰抑制方案设计

为了在跟踪与数据中继卫星系统（TDRSS）中实现码分多址（CDMA）应用,需要完成多用户检测（MUD）及码分多址干扰（MAI）抑制。采用减性多级迭代对消算法,在数字信号处理芯片中完成信号再生、延时校正、时域相减对消,可以完成至少12通道的多用户检测,并能将多址干扰抑制至最小1 dB以内。该算法可作为通用MUD算法的有效补充,并能应用于各类非最优的CDMA系统中,具有迭代级数可选、通道扩展性强、工程实现性好的优点。     

Modelling airline flight cancellation decisions

In order to predict airline responses to Traffic Management Initiatives (TMIs), and reveal the underlying preference structures that shape these responses, we study US domestic airlines’ cancellation decisions in response to the Federal Aviation Administration (FAA)’s TMIs, in particular, to Ground Delay Programs (GDPs). By observing the actual flight-cancellation choices made by airline dispatchers, the airlines’ cancellation utility functions can be inferred through the use of binary choice models. The model captures how delays to a given flight and potential delay savings to other flights affect flight cancellation decisions. We also find larger, fuller, less frequent, shorter-distance, and spoke-bound flights are less likely to be cancelled, and that there is inter-airline variation in flight cancellation behaviour.     

交叉极化干扰消除技术研究

针对双极化频率复用系统中的交叉极化干扰问题,提出了全数字交叉极化干扰消除 器的设计方案,研制了具有交叉极化干扰消除、解调功能的一体化工程样机。测试结果表明 ,该设备对交叉极化干扰的消除效果明显。     

认知OFDM系统旁瓣抑制新方法

针对认知正交频分复用（OFDM）系统带外辐射（OBR）严重问题,在研究基于功率谱密度的主动干扰消除算法（PSD-AIC）模型的基础上,提出了动态PSD-AIC的方法,通过对每一子载波位置OBR的计算,比较选择出OBR取值最小处,作为对消子载波的最优位置,显著改善了系统对OBR的抑制性能（增大约10dB）。对比分析了算法的计算开销,研究了设计参数对OBR的影响,提出了实际应用时的参数选择基准。仿真结果和理论分析表明,动态PSD-AIC方法可以显著减小带外干扰。与PSD-AIC方法相比,旁瓣抑制深度可增加约10dB;与传统AIC方法相比,只需相似计算量,干扰抑制性能便可明显增加。     

用于通信系统的干扰对消电路设计与实现

针对通信设备应用的复杂化和对在复杂电磁环境下工作的设备电磁兼容性提出的更高要求,通过分析对消技术的基本原理,提出了一种模拟电路和数字电路相结合的干扰对消技术,并研制出了基于该技术的干扰对消原理样机。对该样机的单机测试和系统联试结果表明,该对消技术具备点频干扰和噪声干扰的抑制能力,对消收敛时间小于100 ms,对消比大于43 dB,适合在窄带通信中应用并可推广到其他领域。该成果正逐步在实际工程中得到运用。     

论民事二审程序中原告撤诉权的司法适用——兼与李海涛法官商榷

私权自治并不能证成二审撤诉权的自由行使,《民事诉讼法》第13条、第157条也不能成为二审撤诉权的规范依据。二审撤诉权必须以《最高人民法院关于适用〈民事诉讼法〉若干意见的规定》第191条为适用依据。在原告申请撤诉、被告同意撤诉且生效判决尚未确定等要件之下,方可允许原告撤回起诉,且应通过禁止再诉防止原告滥用诉讼权利。     

PCMA自适应自干扰对消算法与仿真

讨论了成对载波多址（PCMA）自适应自干扰对消原理,分析了参数估计误差对自干扰 对消的影响。在频偏误差的影响下对消误差为非平稳过程,传统自适应对消滤波器无法收敛 。为了克服频偏误差的影响,提出了一种自适应可变遗忘因子（VFF） RLS算法,同时,给 出了具有高精度低运算量的模糊函数参数估计算法。仿真证明了VFF-RLS对消算法具有良好 的对消性能和稳健性,且需要的额外功率较低,能满足PCMA系统要求。     

论国际货物买卖合同中的合同解除权

《联合国国际货物买卖合同公约》和《国际商事合同通则》是国际贸易法律制度中的重要法律文件,两者皆把合同解除权作为违约救济的一项重要内容,用不少条款加以详细的规定,作为英美法和大陆法两大法系相互结合的产物,其合同解除权制度的具体内容与我们所熟悉的大陆法系或我国《合同法》上的合同解除权有相当的不同.     

射频干扰对消技术抗单音干扰性能分析

传统的抗射频阻塞干扰方法会引起有用信号的畸变,同时仅部分抑制了射频阻塞干扰。为了解决这些抗干扰方式存在的不足,提出了一种解决方案射频干扰对消,给出了射频干扰对消抗阻塞干扰的实现方法,并对其抗单音干扰的性能做了计算仿真。结果表明,采用射频干扰对消技术后,在Eb/N0相同的条件下,干信比在10~30dB范围内,对误码率没有影响。     

Termination notice of mobile network operator customers after a tariff switch: An empirical study of postpaid subscribers in Germany

Proactive subscriber churn management strategies of mobile network operators (MNOs) require that steps are taken to keep customers before they hand over a formal notice of termination to their provider. Therefore, several studies have analyzed how MNO customers who gave a termination announcement differ from individuals who did not communicate this message. However, no work has examined such differences among subscribers who recently switched to another tariff of their MNO. Therefore, this paper explores socio-demographic, service consumption and tariff change differences between contract cancellation “announcers” and “non-announcers” in a sample of 1810 postpaid customers who had changed their rate plan not long ago. Cancellation announcers were more likely to be males who decreased their mobile voice consumption after their tariff switch, had already attempted to churn in the past, had moved from an unmetered to a metered rate type, paid higher monthly bill amounts and received no discounts on their current rate plan that was introduced on the market some time ago. Among subscribers who gave a termination notice, early (late) cancellation announcers were more likely to be older (younger) customers with a growing (shrinking) SMS consumption after their tariff switch, had not attempted (had already tried) to leave their current MNO in the past, and were in a rate plan that was (not) recently introduced. The findings contribute to the literature on mobile customer retention and have implications for practitioners and scholars.