Ofdm combined with channel coding ( cofdm ) can enhance the ability to lower the effect of multipath fading . 2 信道編碼與ofdm的結合( cofdm ) ,增強系統進一步提高消除多徑影響的能力; 2
54 ye z , krishnamurthy s v , tripathi s k . effects of multipath routing on tcp performance in ad hoc networks . in proc 然而,前者出現了過時的路由信息,后者則會引起亂序,這也會降低tcp的性能。
The effect of multipath propagation commonly exists in the underwater acoustic channel and the fading which was caused by multipath propagation was the main influence factor of underwater acoustic communication system 水聲信道中廣泛存在著多徑傳播效應。由多徑傳播引起的信號衰落現象是影響水聲通信系統性能的主要因素。
Analysis in theory and data processing show that the dgps positioning error comes from the effect of multipath mostly , and rtk positioning error comes from the effect of multipath and the receiver noise 理論分析和數據處理結果表明: dgps的定位誤差主要由多徑效應引起,而影響rtk定位誤差的主要因素包括接收機的測量噪聲和多徑效應。
The effect of multipath , which can not be removed through differential gps positioning , is studied in theory exceptionally . at the same time , the dgps and rtk are constructed , and a lot of dgps and rtk positioning data are collected 2 )分析了影響gps定位精度的各種因素,深入研究了差分系統無法消除的多徑效應;構建了dgps和rtk系統,采集了大量觀測數據。
Chapter 3 investigates the capacity improvement in cdma multi - cellular system with base - station smart antenna . we consider the effects of multipath interference , thermal noise , path loss , processing gain and voice activity factor . and introduces multiuser detection combined with smart antenna 考慮了多徑干擾、熱噪聲、路徑損耗、處理增益和語音激活因子的影響;并介紹了與智能天線技術相結合的多用戶檢測技術。
This paper concentrates on the orthogonal frequency division multiplexing ( ofdm ) technique and some techniques to resist multipath fading . eliminate isi through use of a cyclic prefix . diversity techniques . using adequate ofdm combined with channel coding ( cofdm ) can enhance the ability to lower the effect of multipath fading 本文研究了ofdm的基本原理及抗多徑衰落的一些措施,如加循環前綴,利用多徑進行分集接收,將ofdm與信道編碼及交織結合起來,頻域均衡。
Then combining the idea of likelihood ratio detection and the template matching method , this paper put forward a matching detection method for detecting hovering helicopter using missle - borne pulsed doppler radar . in the third part of this paper , the author analized the effect of multipath to the detection using radar , and put forward a modified m n detection structure to the detection of hovering helicopter under multipath circumstance 本章的第三部分闡述了多徑干擾對雷達檢測性能的影響,提出了一種應用于多徑效應環境中檢測目標回波的修正mm檢測結構并應用于懸停直升機的檢測過程,分析了該算法的檢測性能及其與檢測結構的關系。
Firstly , the effects of short - delay multipath to the dll , pll , and snr of receive signal are discussed . then the effects of multipath to multiple closely spaced antennas are presented . and solve the problem by promote a new method based on extended kalman filtering , which utilize the correlation of measure data of dll , pll and snr of each antenna 最后,利用小范圍多天線系統中多徑信號對接收機碼環、載波環及信噪比影響的相關性,提出了基于擴展卡爾曼濾波器的多徑干擾抑制技術,解決了近距多徑信號的抑制問題。
With the development of information technology and internet , net communication , satellite communication , all kinds of conference call and in some special conditions , like underwater acoustic communication demand it more reliable and can keep secret and be low probability of interception . because of the effect of multipath and doppler shift , the signals through the channel fade rapidly 隨著人類向信息技術和信息網絡時代的邁進,網絡通信、衛星通信、各種電話會議以及某些特殊的通信場合(如水聲通信)中都對通信的保密技術、低截獲率和可靠性提出了更迫切的需要和更高的要求。