TD-SCDMA系统的线性多用户检测算法及性能仿真

在TD-SCDMA系统中,MAI和远近效应的存在使系统性能受到极大的影响,传统的检测器把 MAI作为噪声处理,不能消除MAI和远近效应的影响。讨论了在多径瑞利衰落信道下的多用户检测技术 中的几种不同的检测算法,并对这几种不同的算法进行了仿真和比较。     

OPASTd子空间跟踪算法及其在盲多用户检测系统中的应用

为了提高基于子空间的盲多用户检测方法的性能,在简要介绍了现有的跟踪向量序列的主要子空间和特征元素的快速算法的基础上,提出了正交压缩近似投影子空间跟踪算法(OPASTd),该算法在应用压缩技术的同时,保证了每次迭代估计出的信号子空间的正交性。将该算法应用于多用户检测系统时,系统的抗多址干扰(MAI)和抗远近效应的能力和其他算法相比都有所提高,特别是在抗远近效应方面提高较大。     

OPASTd子空间跟踪算法及其在盲多用户检测系统中的应用

为了提高基于子空间的盲多用户检测方法的性能,在简要介绍了现有的跟踪向量序列的主要子空间和特征元素的快速算法的基础上,提出了正交压缩近似投影子空间跟踪算法(OPASTd),该算法在应用压缩技术的同时,保证了每次迭代估计出的信号子空间的正交性。将该算法应用于多用户检测系统时,系统的抗多址干扰(MAI)和抗远近效应的能力和其他算法相比都有所提高,特别是在抗远近效应方面提高较大。     

实际室内信道DS-CDMA UWB系统盲多用户检测技术研究

提出一种基于常模算法(CMA)的实际室内信道下DS-CDMA UWB系统盲多用户检测方法.该算法采用两步接收方法,第一步,通过分析期望用户特征码具有特殊的结构,压制部分ISI和MAI;第二步在CMA的基础上,消除残留的MAI和ISI,期望用户的信息码元可靠的恢复.计算机仿真显示在考虑远近效应的情况下该算法具有很好的性能.     

WCDMA下行LMMSE接收机算法研究

最小均方误差(MMSE)准则可用在DS-CDMA系统中，能有效地消除MAI和噪声，抗远近效应的单用户接收机和MMSE接收机已成为WCDMA下行链路最有实用前景的接收机。在比较和研究了两种不同结构的LMMSE接收机后，介绍了针对瑞利衰落和多径传输信道而采用的RLS准则的WCDMA下行自适应接收机。仿真结果证实，LMMSE-Rake结构的RLS自适应接收机在严重远近效应条件下具有优良的误码率性能。     

直接序列扩频多用户检测算法

多址干扰以及远近效应是影响扩频系统性能的两大关键问题。多用户检测是一种从接收端设计入手的干扰抑制方法,主要作用是从用户信息相互叠加的CDMA信号中可靠地解调出部分或全部用户的信息。多用户检测技术是消除多址干扰,缓解远近效应,提高系统性能的有效方法,本文介绍了几种经典的用于直接序列扩频的多用户检测算法。     

TD—SCDMA上行链路中的联合检测算法

对TD-SCDMA系统上行链路中的联合检测算法进行了研究，分析各种信道环境下上行链路的性能，并考查联合检测算法抗远近效应的能力，以及信道估计窗对联合检测算法的影响。     

WCDMA下行LMMSE接收机算法研究

最小均方误差(MMSE)准则可用在DS-CDMA系统中,能有效地消除MAI和噪声,抗远近效应的 单用户接收机和MMSE接收机已成为WCDMA下行链路最有实用前景的接收机.在比较和研究了两种 不同结构的LMMSE接收机后,介绍了针对瑞利衰落和多径传输信道而采用的RLS准则的WCDMA下 行自适应接收机.仿真结果证实LMMSE-Rake结构的RLS自适应接收机在严重远近效应条件下具有优 良的误码率性能.     

TD－SCDMA上行链路中的联合检测算法

对TD－SCDMA系统上行链路中的联合检测算法进行了研究，分析各种信道环境下上行链路的性 能，并考查联合检测算法抗远近效应的能力，以及信道估计窗对联合检测算法的影响。     

异步DS-CDMA系统中基于线性预测的直接盲均衡

应用了最近提出的针对直接序列扩频码分多址(DS—CDMA)系统反向链路(异步传输模式)的线性预测方法，通过对接收信号进行线性变换，在所需用户扩频码已知的情况下，得到其信道列矢量子空间，然后在此基础上进行MMSE均衡器和迫零均衡器的设计，以达到同时消除MAI和ICI的目的。应用直接盲均衡处理，能够避免信道估计可能的误差对多用户检测性能所产生的影响。仿真结果表明，算法的准确性和鲁捧性得到明显提高，并且有较好的对抗远近效应的能力。     

非接触式汽车驾驶员心电监测系统设计

驾驶员疲劳驾驶是引发道路交通事故的主要原因,依据心冲击图（BCG）、呼吸等生理参数客观监测行车过程中的驾驶员疲劳状态成为了研究热点。针对传统生理信号采集需用复杂电极和导联线接触人体的弊端,基于偏聚氟乙烯（PVDF）压电薄膜的正压电特性,设计了一种非接触式汽车驾驶员心电监测系统。构建了可靠的小信号调理和电压抬升电路,研究了心冲击图和呼吸信号的分离提取算法,计算出心率和呼吸率并通过低功耗蓝牙通信发送到手机软件（APP）进行显示。实验表明,系统能实时可靠的监测行车中驾驶员的心率和呼吸率,提高了汽车行驶的主动安全性。     

TD—SCDMA系统中联合检测的原理和实现

联合检测技术是TD－SCDMA系统的关键技术之一,在介绍CDMA系统模型的基础上,详细分析了基于近零线性均衡的联合检测技术及其FPGA和DSP实现方法,它是TD－SCDMA系统中所用的一种抗多址及多径干扰技术,可以消除通信系统中的大部分干扰,从而降低了整个系统的误码率,使通信系统的容量和通信质量得以显著提高。     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

橡胶颗粒沥青混合料低温抗裂性试验研究

以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。