异步差分跳频扩谱多址系统的性能分析

提出了一种计算异步差分跳频扩谱多址系统在多用户干扰条件下误码率的方法。利用此方法进行数值计算的结果表明 :在多用户干扰条件下 ,异步差分跳频扩谱多址系统的误码性能明显优于传统的采用 BFSK调制和非相干解调的慢速跳频系统。

智能手机异步GNSS差分定位解算方法及精度评定

针对智能手机内置的全球卫星导航系统(GNSS)模块经常会在非整秒时刻输出原始观测数据,导致难以和基站形成有效同步观测,进而无法实现高精度差分GNSS导航与定位应用的问题,提出一种智能手机异步GNSS差分定位的解算方法:采用邻近历元检索法和相邻历元内插法分别对智能手机GNSS的异步观测数据进行处理;并对定位结果的精度进行对比分析。实验结果表明,2种方法都可以有效解决智能手机GNSS终端数据和基站数据不同步的问题,并且与伪距单点定位相比,均方根误差从20多米提升到2m左右,精度得到了大幅提升;2种方法定位精度的差异均在0.1m以内,并且内插法定位结果的精度要略优于搜索法,但内插法对卫星连续观测有较高要求,建议采用相邻历元检索法处理智能手机异步GNSS观测数据。

A Simultaneous Optimization Method for the Structure and Compo-sition Differences of a Mass Exchange Network

This article presents a new method to calculate the composition differences （e） for tar g.etin.g the minimum total annualized cost （TAC） of a mass exchange network （MEN）,which is based on the combination of composition interval diagram （CID） with mathematical programming.The total cost target consists of the capital cost of the process units and the operating cost for mass separating agents （MS.As）. The value of total cost varies considerablv with the composition differences, so the values of e should be optimized in order to obtain minimum TAC of a MEN. This articleconsiders ε as a set of unequal variables for each equilibrium equation of a rich-lean stream pair, employing them to build the CID and mathematical model, which optimizes the structure and composition differences simultaneously. Two examples are applied to illustrate the proposed method and the results demonstrate that the approach introduced by this article is simpler and more convenient than the methods in previous literatures.

GNSS异步RTK定位效果分析

分析了GNSS(global navigation satellite system)卫星钟差在通信延迟内变化的量级,同时对比分析了不同系统异步RTK(real-time kinematic)定位精度。实验结果表明,与传统RTK模型相比,在考虑通信延迟内钟差变化的影响时,BDS/Galileo/GPS的RTK定位精度明显提高,GLONASS在通信延迟较低时无明显变化。其中,对于同样的通信延迟,BDS/Galileo的异步RTK定位精度明显优于GPS/GLONASS。