Dinghai Xu

Learn More
This paper develops an efficient method for estimating the discrete mixtures of normal family based on the continuous empirical characteristic function (CECF). An iterated estimation procedure based on the closed form objective distance function is proposed to improve the estimation efficiency. The results from the Monte Carlo simulation reveal that the(More)
Volatility clustering is a well-known stylized feature of financial asset returns. In this paper, we investigate the asymmetric pattern of volatility clustering on both the stock and foreign exchange rate markets. To this end, we employ copula-based semi-parametric univariate time-series models that accommodate the clusters of both large and small(More)
Code-Division Multiple-Access (CDMA) [1] is widely used in both civil and military applications. It does take advantages from the system characteristics. For example, higher data rate and user capacity, better multipath resolution [2] and resistance to jamming, low probability of interception, accurate timing and ranging, and more importantly, stronger(More)
In order to meet the QoS demand of the time-sensitive information transmissions in airborne networks, a multi-priority differentiated and multi-channel MAC protocol based on the adaptive jitter mechanism is proposed in this paper. The protocol provides differentiated QoS services for different priorities by different maximum jitter stages. According to the(More)
New generation air traffic control requires the communication system to improve data rate and system capacity. Traditional TDMA and FDMA system can support limited users. Code Division Multiple Access (CDMA) may take advantages to provide better performance. Data rate and user capacity are two aspects of it. To a CDMA for air traffic control, Multiple(More)
Channel quality parameters are needed to achieve efficient utilization of radio resources. These parameters include channel amplitude gain, channel frequency offset, channel random phase, channel multipath as well as channel noise variance. Usually, signal-to-noise ratio (SNR) at the demodulator output is used as channel quality indicator to link bit error(More)
It is an important issue to design wireless communication and networking that radio resources should be efficiently utilized while providing guaranteed Quality of Service (QoS). In this area, link adaptation based on accurate channel quality estimation has attracted a lot of attention from both academia and industry. Topics such as power control, adaptive(More)
  • Dinghai Xu
  • 2010
This paper investigates an efficient estimation method for a class of switching regressions based on the characteristic function (CF). We show that with the exponential weighting function, the CF based estimator can be achieved from minimizing a closed form distance measure. Due to the availability of the analytical structure of the asymptotic covariance,(More)