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。     

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.     

契约条款影响债券价格吗？——基于中国公司债市场的经验研究

本文着眼于债券契约条款具有保护债权人权利的本质属性,将公司债券的总价差分解为信用价差和非信用价差,通过手工整理数据,应用组合排序法及Fama-Macbeth方法,研究了债券契约条款对债券定价影响的途径和程度。结论表明:债券契约条款由于能够保护债权人的未来权益,减少债权人承担的风险,从而能够有效降低债券的信用价差和非信用价差,并且债券契约条款对信用价差的影响程度更大;通过信用价差和非信用价差两种影响效应的叠加,债券契约条款同样能够显著降低债券到期收益率的总价差。     

Determinants of the components of bid-ask spreads on stocks

In this paper we show that George et al. (GKN, 1991) estimators of the adverse selection and order processing cost components of the bid-ask spread are biased due to intertemporal variations in the bid-ask spread. We use alternative estimators that correct this bias and that are applicable to individual securities, and estimate these cost components empirically using data on NYSE/AMEX stocks. As expected, our results indicate that on average adverse selection costs account for approximately 50% of the bid-ask spread, sharply higher than the estimates of 8-10% obtained by GKN for NASDAQ stocks and 21% that we obtain for NYSE/AMEX stocks using GKN's estimators. We then conduct cross-sectional regressions designed primarily to determine whether adverse selection costs vary across specialists after controlling for firm size and other factors. Consistent with previously established hypotheses, we find that adverse-selection costs vary across specialists, and that this variation is related to the number of securities that the specialist handles.     

多重直序扩频信号的相关接收

本文说明了利用伪随机(PN)码的相关特性,进行多重直序扩频信号相关接收的基本原理。指出了这项技术在卫星多址通信中的重要意义,并对实验结果进行了分析,得出了一些重要的结论。     

Effects of speculation and interest rates in a “carry trade” model of commodity prices

The paper presents and estimates a model of the prices of oil and other storable commodities, a model that can be characterized as reflecting the carry trade. It focuses on speculative factors, here defined as the trade-off between interest rates on the one hand and market participants' expectations of future price changes on the other hand. It goes beyond past research by bringing to bear new data sources: survey data to measure expectations of future changes in commodity prices and options data to measure perceptions of risk. Some evidence is found of a negative effect of interest rates on the demand for inventories and thereby on commodity prices and positive effects of expected future price gains on inventory demand and thereby on today's commodity prices.     

Intraday patterns in London listed Exchange Traded Funds

In this paper we examine the intraday trading patterns of Exchange Traded Funds (ETFs) listed on the London Stock Exchange. ETFs have been shown to be characterised by much lower bid–ask spread costs and by lower levels of information asymmetry than individual securities. One possible explanation for intraday trading patterns is that concentration of trading arises at the start of the trading day because informed traders have private information that quickly diminishes in value as trading progresses. Since ETFs have lower trading costs and lower levels of information asymmetry we would expect these securities to display less pronounced intraday patterns than individual securities. We fail to find that ETFs are characterised by concentrated trading bouts during the day and therefore find support for the argument that information asymmetry is the cause of intraday volume patterns in stock markets. We find that ETF bid–ask spreads and volatility are elevated at the open but not at the close. This lends support to the “accumulation of information” explanation that sees high spreads and volatility at the open as a consequence of information accumulating during a market closure and impacting on the market when it next opens.     

On the short-maturity behaviour of the implied volatility skew for random strike options and applications to option pricing approximation

In this paper, we propose a general technique to develop first- and second-order closed-form approximation formulas for short-maturity options with random strikes. Our method is based on a change of numeraire and on Malliavin calculus techniques, which allow us to study the corresponding short-maturity implied volatility skew and to obtain simple closed-form approximation formulas depending on the derivative operator. The numerical analysis shows that these formulas are extremely accurate and improve some previous approaches for two-asset and three-asset spread options such as Kirk’s formula or the decomposition method presented in Alòs et al. [Energy Risk, 2011, 9, 52–57]. This methodology is not model-dependent, and it can be applied to the case of random interest rates and volatilities.     

补码键控技术及其在无线局域网中的应用

补码键控技术是一种多进制编码扩频技术。本文介绍了该技术的相关函数特征及序列结构，并以无线局域网基带处理器HFA3861A为例，介绍了CCK扩频调制方式的典型应用。     

统一扩频测控体制的初步探讨

分析了我国航天测控面临的新问题、新要求和现行航天测控体制的局限性，对新的统一伪码扩频测控体制进行了初步的描述和设计。