direct sequence signal 中文意思是什麼
direct sequence signal
解釋
直接序列信號-
A novel communication receiver which uses lapped transform ( lt ) incorporating modified median filter ( mmf ) algorithm is designed for narrow - band interference excision. the lt domain mmf algorithm takes full advantages of the direct sequence spread spectrum signal, as well as the characteristics of lt, performing the transform domain filtering twice. the first filtering locates the position of interference and mitigates most of them. the second filtering is performed in a small neighborhood of the located interference. so lt domain mmf algorithm can completely mitigate the interference without distorting the desired signal. simulation results demonstrate the improved ber performance and increased robustness of our receiver
本文採用改進的重疊變換域中值濾波演算法進行變換域抗干擾處理.該演算法既考慮到直接序列擴頻信號的特點，同時又利用重疊變換的特性對變換域系數進行了二次濾波.該演算法節省處理時間，並且不需要有關干擾的先驗知識，系統性能不會隨干擾頻率變化而變化，因而是一種很穩健的處理方法 -
In wcdma system which uses direct sequence to spread spectrum, the spread spectrum code ( pn code ) phase of the receiver must be synchronized with that of the received signal precisely to despread and demodulate the signal correctly. multipath channel exists in the mobile communication environment for the radio signal reflection by obstacles between transmitters and receivers. by using the autocorrelation of the spread sprectrum code, rake receiver can process received signals and therefore multipath components can be resolvable
在wcdma系統中，為正確解擴解調接收到的擴頻信號，接收機本地產生的擴頻碼（ pn碼）相位必須和接收信號中的擴頻碼相位完全同步;同時移動通信環境中的傳輸信號由於接收機和發射機之間的直達路徑有可能被建築物或其他障礙物所阻礙，總是經過折射或反射的多條路徑后才到達接收機，從而產生多徑通道。 -
Aiming at the problem of intercepting the direct sequence spread spectrum communication signal, this paper makes full use of the wave characteristic of base - band signal after it is applied to shaping filter is made, and an algorithm which is based on the average power serial is given
摘要針對直接序列擴頻通信信號的偵察問題，充分利用擴頻基帶信號發送成型濾波后的波形特點，提出了一種基於最大平均功率序列的演算法。 -
But modern electronic counterwork technic could exactly estimate the carrier frequency, signal period, even the pseudo - random ( pn ) sequence itself of direct sequence spread spectrum ( dsss ). it is urgency to investigate a new dsss to achieve lower probability of detection ( lpd ) and higher anti - jamming
然而現代電子對抗技術可以準確估計直接序列擴頻通信的載波頻率、符號周期甚至擴頻碼本身，為達到更低截獲率和更高抗干擾的通信目的，必須研究新的直擴通信技術。 -
In the text, direct sequence spread spectrum signal ( dsss signal ) is the main object, and some nonlinear methods based on chaotic theory, used in the prediction of signal and detection of signal is studied
本文以保密通信中廣泛使用的直接序列擴展頻譜信號（ dsss信號）為主要對象，研究了一些基於混沌理論的非線性的方法在信號預測和信號檢測中的應用。 -
With the development of the modern electronic counterwork techniques, the estimate of the carrier frequency, signal period, and even the pseudo - random ( pn ) sequence itself of direct sequence spread spectrum ( dsss ) is possible
隨著現代電子對抗技術的發展使得估計直接序列擴頻通信的載波頻率、符號周期甚至擴頻碼本身變為可能。 -
Direct sequence spread spectrum ( dsss ) system usually operates in the condition of low signal - to - noise ratio ( snr ). the receiver extracts information from the signal through correlation operation by the spread code
直接序列擴頻通信系統通常工作于低信噪環境中，接收機以擴頻碼對信號相關解擴提取信息。 -
Additionally, since direct spread spectrum sequence ( dsss ) signal has an ultra - low power spectrum density, finding approaches to detect it and estimate its parameters in the non - cooperative communication system is a great challenge for applications
另外， dsss信號由於具有極低的功率譜密度，如何在非協作通信中不知道擴頻序列的前提下對其進行檢測和估計，是一個具有很強應用背景的課題。 -
Direct sequence spread spectrum ( dsss ) communication systems have the characteristics of wide spectrum, low working signal - to - noise ratio ( snr ), anti - interference, anti - multipath effect, capability of cdma, lpi and lpd
直接序列擴頻（英文簡稱dsss ）通信具有頻譜寬、工作信噪比低、抗干擾和抗多徑效應能力強、可實現碼分多址、低截獲和低檢測概率等特點。 -
The hardware design includes pl2101 power line node, realization of narrow - band interferences in direct sequence spread spectrum signal using frequency - domain algorithm
其中硬體設計包括pl2101電力線節點、窄帶干擾自適應抑制系統的實現。 -
Direct - sequence spread spectrum ( dsss ) takes a signal and " spreads " it over several frequencies, essentially creating redundant signals
直接順序擴頻（ dsss ）取出信號，把它「散布」到幾個頻率上，實質上形成了冗餘的信號。 -
The problem of signal processing for direct - sequence code - division - multiple - access ( ds - cdma ) signal over multipath frequency - selective mobile channels is considered. a new blind receiver is proposed. without the knowledge of the multiple - access interference users spreading code and the channel characteristics, the receiver achieves blind detection with prior knowledge of only the desired users spreading code and approximate timing. by using reduced rank adaptive decorrelating filter and adaptive multipath combiner which is based on decision - directed algorithm, the receiver gets the ability to combat both fading and the near - far effect at low cost. simulation results demonstrate that the proposed receiver offers high performance
本文研究多徑頻率選擇性衰落通道下直接序列擴頻碼分多址（ ds - cdma ）信號的處理問題，提出了一種新型的盲接收機.該接收機不需預知多址干擾用戶的擴頻碼，不需預知通道參數，只需已知期望用戶的擴頻碼和粗略的定時，就可以完成用戶的盲檢測.同時，該接收機通過降維自適應去相關濾波和基於判決指導的自適應多徑合併，來獲得低成本和良好的抗衰落、抗遠近效應性能.模擬結果驗證了本文提出的接收機的優良性能 -
The direct sequence spread spectrum ( dsss ) signal has been widely used, owing to the ability of lower working signal - to - noise ratio ( snr ), strong anti - jamming, lower probability interception and mitigating the effects of multi - path fading
直接序列擴頻（ dsss ）信號由於具有工作信噪比低、強抗干擾性、低截獲率、能夠抑制多徑效應等優點，已經得到廣泛應用。
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