direct sequence cdma 中文意思是什麼

direct sequence cdma 解釋
直接序列碼分多址
  • direct : adj 1 筆直的，一直線的；正面的。2 直接的。3 直截了當的，直率的，明白的。4 直系的，正統的。5 【語...
  • sequence : n 1 繼續；接續；連續。2 順序；程序；次第；關系；關聯。3 後果；結果；接著發生的事；後事；後文。4 ...
  1. Then studies a peculiar multi - carrier direct sequence spread spectrum ( mc - ds - cdma ) technology, analyzes the methods of processing multi - carrier signals and study the mathematical module of multi - carrier communication system receiver

    然後對本文所研究的這種特殊的多載波直接序列擴頻技術進行闡述，分析了多載波信號處理的方法和研究了多載波接收機的數學模型。
  2. Direct sequence - code divition multiple access ( ds - cdma ) technology is achieved easily and used widely at present its receiver capability is confined by two factors, one of which is the multiple access interference ( mai ) which makes the capacity low, another of which is the near - far problem

    直接序列擴頻-碼分多址（ ds - cdma ）技術是最易實現、也是目前應用最廣的一種方式，它的接收性能受到兩個主要的限制：一個是多址干擾造成的性能下降；另一個則是遠近效應問題。
  3. For wireless communications, direct sequence code division multiple access ( ds - cdma ) techniques have received a great deal of attention due to the expectation of capacity increase, interference rejection capability, security, and so on. in a high data rate application such as multimedia services, however, the capacity of ds - cdma systems is limited by both the inter - chip, or inter - symbol interference

    Cdma技術以其高抗干擾能力、高容量、高保密性等技術優勢在第三代移動通信系統中被廣泛應用，然而在高速數據業務中，嚴重的碼間干擾和符號間干擾會導致系統性能明顯下降。
  4. In this thesis, the zero correlation zone ( zcz ) or generalized orthogonal ( go ) sequences are applied to direct - sequence cdma ( ds - cdma ) systems, and the corresponding system performance are analysed. topics on the correlation property analysis of hadamard walsh ( wh ) sequences, go sequences, and loosely synchronous ( ls ) sequences are performed, and the system model and performance evaluation of single - cell and multi - cell synchronous cdma ( s - cdma ) systems employing go sequences, and the applications of go sequences in quasi - synchronous cdma ( qs - cdma ) systems are elaborated

    本文研究了零相關區（ zcz ）或廣義正交（ go ）序列在直接序列碼分多址（ ds - cdma ）系統中的應用並給出了系統性能分析結果，包括hadamardwalsh （ wh ）序列集、廣義正交序列集與鬆散同步（ ls ）序列集相關特性分析，採用廣義正交序列的單小區與多小區同步cdma （ s - cdma ）系統模型與性能分析，以及廣義正交序列在準同步cdma （ qs - cdma ）系統中的應用等問題。
  5. Then taken four kinds of maps for examples, comparing with m - sequence, their properties are calculated, verifying the advantages of the chaotic sequence generated by the new method. after this, an improved scheme is discussed - - using m - sequence to change the sequence ’ s turn and verifying that the permutation parameters have effect on improving the sequence ’ s properties. in chapter 5, monte carlo simulation method is used to test performances of our sequences ’ applications in the given model of direct spread spectrum cdma system, and results of error rate of the system are given ; the comparing resuls of performances of anti - multi - access interference and anti - multi - address interference of different pn sequence is also shown in this thesis

    本文首先對擴頻通信中常用二進制偽隨機序列的產生方法、性能特點進行了總結，指出了現有二進制偽隨機序列的應用局限性;其次，根據混沌非線性系統特徵，深入研究了混沌數字序列的產生方法;在此基礎上，提出了一種新的產生方法中間抽取法，然後，以四種混沌映射系統為例，對其所產生的混沌數字序列進行了偽隨機特性實驗數據分析，並與m序列進行比較，結果說明了混沌數字序列代替傳統擴頻序列的優點，同時驗證了新方法的可行性。
  6. The technology of direct sequence spread spectrum / code division multipul access ( dsss / cdma ) are applied in the broadband code division multiplex wireless communication systems, which means transmitting data at the rate of 2. 048mbps using four e1 lines within the band of 20mhz. in this paper, the theory of the whole debice is first analysized specified for the system asic design and optimizing its performance

    寬帶碼分復用無線傳輸系統是採用直接序列擴頻/碼分多址（ dsss / cdma ）技術，在20mhz頻帶內實現四路2 . 048mbps的e1鏈路數據速率的無線傳輸。本文首先分析了整個數傳設備實現原理，針對系統asic設計和優化整機集成性能出發，提出並實現了基於fpga控制pm4314e1晶元的介面模塊完成對e1鏈路信號的監控和告警功能的改進方案。
  7. Direct sequence spread spectrum ( ds ) signals have been widely used for secure communication and mobile communication known as code division multiple access ( cdma ) system. because ds signals have many advantages such as anti - jamming capability, low probability of interception, multiple access capability and so on

    直接序列擴頻通信具有低截獲概率，抗干擾能力強以及實現碼分多址等優點，因而在抗干擾通信及民用移動通信中得到廣泛的應用。
  8. Broadband direct sequence cdma for fixed wireless pstn access - layer 2

    固定式無線pstn訪問用寬帶直接順序cdma . 2層
  9. Broadband direct sequence cdma for fixed wireless pstn access - layer 1

    固定式無線pstn訪問用寬帶直接順序cdma . 1層
  10. This thesis is focoused on the pn sequence of direct spread cdma communication system, including it ' s generation and properties analyzing. at first, this thesis expounds linear - shift - register sequence and chaotic sequence, and calculates the value of their main properties

    本文的研究的是直接序列擴頻的碼分多址（ codedivisionmultipleaccess ，簡稱為： cdma ）通信系統中的偽隨機序列技術，包括它的產生方法和性能分析。
  11. 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。
  12. Secondly, in the research of communication, the direct - sequence code division multiple access ( ds - cdma ) is an important component of numerous recent communications systems, proposed and implemented

    其次，在通信領域，本文主要針對當前研究的一個熱點問題? ? cdma多用戶檢測，展開研究。
  13. 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
  14. Concerning with the direct sequence ( ds ) cdma system, this thesis focuses on several issues related to orthogonal spreading sequences and amc, including correlation properties of orthogonal variable - length spreading sequences and their effects on ds cdma system performance, performance of multicarrier ( mc ) ds cdma system with generalized orthogonal ( go ) sequences, adaptive modulation with throughput maximization, performance of adaptive turbo - qam coded modulation in generalized fading channel and performance of amc in wcdma high speed downlink packet access ( hsdpa )

    針對直接序列碼分多址（ dscdma ）系統，本文主要研究了正交擴頻序列和自適應調制編碼若干問題，包括正交變長擴頻序列的相關性及其對dscdma系統性能的影響、採用廣義正交（ go ）序列的多載波直接序列碼分多址（ mcdscdma ）系統性能、吞吐量最大化自適應調制、自適應turbo - qam編碼調制在廣義衰落通道中的性能，以及wcdma下行分組接入（ hsdpa ）中自適應調制與編碼性能五個方面。
  15. Cdma is a main technique of the third generation wireless personal communication system. it adopts to the method of spread spectrum ( ss ), so the quality of the ss sequence affects the system performances directly. this thesis focused on the chaotic digital sequence of direct spread spectrum cdma communication system, including its generation, characteristics and application properties analyzing

    碼分多址（ codedivisionmultipleaccess ，簡稱cdma ）是第三代無線個人通信系統的一項主要技術，它採用擴頻通信方式，而擴頻序列的好壞直接關繫到擴頻通信系統性能的好壞。
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