一种通用数字中频正交扩频调制器的实现

提出了一种适应于宽带扩频通信系统的数字中频调制的实现方案,它基于正交调制、DDS、数字上变频和数字内插等技术,采用通用硬件平台,可以生成多种中频调制信号,可广泛用于数字化扩频通信电台、宽带CDMA、软件无线电、遥控遥测等通信系统中。     

直接序列非相参扩频系统抗干扰性能的研究

<正> 我国是一个人口众多,人均资源相对贫乏,经济、文化比较落后的发展中国家。要在这样的国家实现科学技术的现代化,建设一个现代化的工业强国,依赖外国不行,闭关自守也不行。坚持自力更生为主,积极吸收国外科学技     

The market microstructure of the European climate exchange

This paper analyzes the market microstructure of the European Climate Exchange, the largest EU ETS trading venue. The ECX captures 2/3 of the screen traded market in EUA and more than 90% in CER. Volume growth has averaged 277% in EUA between 2005 and 2009 and 724% in CER since 2007. Spreads range from €0.0188 to €0.0406 for EUA and €0.0276 to €0.0796 for CER. The median proportion of the spread due to adverse selection reaches 76% for EUA and 75% for CER. Realized volatility, bid-ask spreads and adverse selection costs decline with verified emission releases. Market impact estimates imply that an average trade will move the EUA market by 1.06 euro centimes and the CER market 1.45. The ECX is providing between 75% and 88% of price discovery for EUA trading and between 64% and 72% for CER. We find imbalances in the order book help predict returns for up to three days. A simple trading strategy that enters the market long or short when the order imbalance is strong is profitable even after accounting for spreads and market impact.     

Quote inefficiency in options markets

In an arbitrage-free economy with non-zero bid-ask spreads the existence of payoffs whose price is lower than the price of a dominated payoff cannot be discarded in general. However, when the former price corresponds to trivial portfolios which involve buying or selling one unit of the basis assets, its presence, although not an arbitrage, is a severe market anomaly which we refer to as an inefficient quote. In an empirical study, we report evidence that indicates that in options markets both the frequency and the magnitude of these anomalies are substantial and we document puzzling patterns in their behavior.     

Risk sentiment and firms’ liquidity in the French market

This paper investigates the impact of risk sentiment on market liquidity by using panel data. We use six risk word lists; uncertain, weak model, negative, legal, opportunity, and environmental & social responsibility word lists to measure the risk sentiment. Concerning the liquidity proxies, we use three measures, quoted spread, effective spread, and adverse selection component. The results indicate that an intensive risk tone and uncertain information in annual reports lead to decreased liquidity. In addition we find that risk sentiment variable impacts the liquidity but not vice versa.     

Intraday data and hedging efficiency in interest spread trading

Three government bond futures contracts and their respective 3-month interest rate futures contracts traded on LIFFE are examined. The data period covers three years of observations, January 1994-December 1996, sampled at half-hourly intervals. Borrowing from the calculation of minimum variance hedge ratios, half-hourly minimum variance spread ratios (the ratio of one contract to another, which provides the minimum variance) are estimated for the above contracts. The hypothesis under examination is whether there is any value-added in estimating minimum spread ratios based on intraday data. Three spread ratios are defined: two ratios calculated from daily data and a third one based on intraday data. Evidence tends to indicate that spread ratios calculated from intraday data exhibit a substantially lower variance than the other two spread ratio speciications. Thus, it is shown that intraday data, in comparison with daily data, allow for lower hedging costs. Moreover, the use of intraday-based spread ratios might be a contributing factor to reducing the maximum cumulative loss potentially incurred while holding a spread position.     

信息披露质量与市场流动性

本文以深交所A股上市公司为样本．研究上市公司的信息披露整体质量是否影响公司股票在市场上的流动性。基于分笔高频交易数据．检验集中于流动性的两个关键方面：市场宽度和市场深度。采用稳健的非线性两阶段最小二乘法来克服信息披露的自选择特点所引起的内生性问题。实证结果显示，公司高质量的信息披露能有效提高其股票的市场流动性，这种影响主要是通过缩小市场宽度来达到．而对市场深度的影响不显著。利用市场微观结构的价差分解方法的研究发现．高质量的信息披露提高市场流动性的机制在于有效减轻市场上信息不对称程度。     

我国利率市场化进程中商业银行的利率风险管理分析

本文旨在通过对利率风险管理方法演变历程的概览,还原我国利率市场化下真实的利率风险环境和我国银行业的风险管理水平,揭示利率风险管控重点——利差的合理性,并探寻其忽视内含期权所致的真实利差偏差的重要隐患。实证分析我国存贷利差合理性的基础上,得出存在偏离真实合理水平的结论。由此,提出期权调整利差（OAS）模型,结合金融工程产品分解和期权定价思想,展示其操作流程与方法对比。所得调整后利差,运用于有效久期-凸度管理模型,形成完整的利率风险管理体系,从而提出了有关风险管理方法工具、银行业务拓展和市场数据系统建立的建议。     

GEOSTAR卫星无线电定位系统扩频接收机的实现

GEOSTAR卫星无线电定位系统是为美国本土和世界各地妁地面移动用户以及航海、航空用户提供准确的位置信息和辅助双向信息。用户至Geostar中心线路由移动站的发射机、中继卫星和中心接收站组成并已经建成。来自用户终端的扩频和卷积编码的突发射频信号通过卫星被中继到GEOSTAR中心,由该中心进行信息包的捕获、解调和处理。在突发工作方式的扩频系统中,传输和数据误差率取决予线路特性、捕获概率、虚警概率和使用的解调器数量。本文比较了用户至GEOSTAR中心线路理论和实测传输特性和数据误差特性。     

抗干扰通信/定位系统用户端机的数字实现

本文介绍了一种抗干扰通信／定位系统端机中频单元的原理与实现。该端机可以同时实现数据通信和测距，并且有较好的灵活性和通用性。文中给出了硬件框图和部分软件流程。