相干多通道 的英文怎麼說

中文拼音 [xiānggānduōtōngdào]
相干多通道 英文
cmc coherent multi-channel
  • : 相Ⅰ名詞1 (相貌; 外貌) looks; appearance 2 (坐、立等的姿態) bearing; posture 3 [物理學] (相位...
  • : 干Ⅰ名詞1 (事物的主體或 重要部分) trunk; main part 2 (幹部的簡稱) short for cadre Ⅱ動詞1 (做...
  • : 通量詞(用於動作)
  • : Ⅰ名詞(道路) road; way; route; path 2 (水流通過的途徑) channel; course 3 (方向; 方法; 道理) ...
  • 相干 : 1 (多用於否定句或疑問句) have to do with; be concerned with 2 [物理學] coherent; 相干散射 coher...
  • 通道 : thoroughfare; passageway; pass; enterclose; gallery; drong; tunnel; avenue; alure; way; row; key ...
  1. Traditional multiuser detector make good use of all signals which resuilt in multiple access interference so that it provides optimum mai resistance. ( 1 ) nevertheless, it assumes that the receiver can acquire the signature waveform and timing of desired user and the interfering users ; ( 2 ) it has no ability to suppress intercell multiple access interference ; ( 3 ) it cannot be applied in downlink channels. adaptive multiuser detector eliminates the need to know the signature waveforms and the timing of the interferes and has to need training data sequences for every active user

    傳統用戶檢測在單用戶檢測技術基礎上,充分利用造成擾的所有用戶的信息進行聯合檢測,從而具有良好的抗擾能力,但存在一些缺陷: ( 1 )不僅要求知期望用戶的地址pn碼及其定時信息,還要求其他擾用戶的地址pn碼及其定時信息; ( 2 )不能消除其他鄰小區的擾對本小區的影響; ( 3 )不能直接應用在cdma移動信系統中的下行鏈路。
  2. This thesis analyzed the error performance of mfsk and mpsk modulator in hf with optimal receiver, studied the shortcoming and strongpoint of several typical short - wave data transmission systems and their performance over fading and intersymbol interference channels. the theory and key technical of adaptive modem is discussed. in the last, an efficient modulation scheme - block coded modulation is introduced into hf radio systems to improve the efficiency of hf data transmission, this paper also proposes a hf data transmission system scheme composed of a block coded modulator and a decision feedback type adaptive equalizer

    本文在對短波數傳兩種常見調制方式fsk及psk最佳解調性能分析的基礎上,討論了幾種採用典型調制技術的短波數傳系統(如時頻調制、進制頻移鍵控慢跳頻、 chess系統)原理、優缺點以及抗衰落和抗符號間擾的性能;分析了自適應串列數傳系統抗短波衰落和擾的原理、關鍵技術;在本文的最後引入一種有望解決短波數傳系統低效率狀況的調制方式bcm -分組編碼調制,給出了一個採用bcm技術與自適應均衡技術結合的短波數傳系統方案,並過計算機模擬進行了初部驗證。
  3. With the development of the fiber communication, very high speed fiber optic backbone has being closed to the customer, but few customers has connected to fiber backbone directly. on the other hand, many customers are running some high speed network within their lan, such as fast ethernet ( 100mbps ), or gigabit ethernet ( 1. 0gbps )

    隨著光纖信技術的發展, 2 . 5g - 10gbps的光纖線正在不斷的向用戶延伸,但由於成本和光纖敷設工程上的難,只有很少的用戶直接和光纖連,常光纖只延伸到了路邊、小區;另一方面,許用戶內部的局域網也具有很高的傳輸速率,一般為100mbps甚至1gbps的以太網。
  4. The cause of shipping must have a flourish development with the access to world trade organization and further reformation of economy system of our country. it is imperious need to understand the hydrodynamic forces acted on ship hull while the amount of ships in the sea - routes is increasing. these forces, especially the changing tendency of hydrodynamics when the two ships are meeting or a ship is passing a pier are of great importance to avoid the shipwrecks such as ship collision

    隨著我國加入wto以及經濟體制改革的深入進行,航運事業必然會得到蓬勃發展,而面對航中日益增的船舶,人類迫切需要了解船體上所受到的水動力情況,尤其是船體過橋墩、兩船遇時的擾水動力變化趨勢,這些對避免船舶碰撞等海難事故的發生具有重要意義。
  5. 4. we propose that the best detection method for the uplink mc - cdma system is decorrelating - parallel interference cancellation ( dec - pic ) multiuser detection, and the best detection method for the downlink mc - cdma system is minimum mean square error combining ( mmsec ) single user detection

    提出上行mc - cdma的最佳檢測方法是解關-并行擾抵消用戶檢測法( dec - pic ) ,在下行mc - cdma的最佳檢測方法是最小均方誤差合併單用戶檢測法( mmsec ) 。
  6. The directional routing protocol ds _ dsr put forward by the author is the improvement of the current protocol dsr, complete routine discovery and maintenance by directional neighbor nodes routing table, source routing and directional steering. the research discovers the application of the directional antenna, compare the omnidirectional antenna can increases the networks " total throughput, obviously reduces the co _ channel interference ( cci ), multiple access interference ( mai ), enlarges the nodes " signal and interference to noise ratio ( sinr ), and because of the high gain of directional antenna can realize the communication with farther distance and less jump, end to end delay can decrease deeply, simultaneously, security of networks can be improved partially, the node energy also can be saved easily by power control

    本文提出的定向路由協議ds _ dsr是基於對現有協議dsr的改進下實現的,過定向鄰節點路由表、定向源路由和定向搜索來完成路由發現與維護。研究發現,定向天線的應用,比全向天線可明顯提高網路的總的吞吐量,減少擾、擾,提高信噪比,且由於定向天線的高增益可實現較遠距離、較少跳數的信,減少了路由發現時間,這樣大大減小了傳輸時延,網路的整體性能得到了不同程度的提高,同時部分地解決安全問題,過功率控制還可較容易的實現節能的目的。
  7. A kind of mud based on transversal equalizer is recommended, and the performance analysis of ds - cdma systems based on that mud has been done under synchronous channels. then the expression of output signal is deduced. also, the relations among sinr of output signal, snr and correlation matrix of spread code the least mean square error ( lms ) adaptive algorithm is applied to the mud

    論文引入基於橫向均衡結構的用戶檢測器,用矩陣方法推導了awgn下、同異步系統中信號輸出表達式,依據最小均方差準則,討論了同步方式下檢測器的輸出信號擾比與信噪比、擴頻碼關陣以及用戶功率大小等因素間的關系。
  8. Conventional detector ( single - user matched filter ) distinguishes each user by the crosscorrelation of their spread - spectrum codes. in practice, however, its performance is much deteriorated due to the existence of noise in channel and strong multi - access interference, i. e. near for effect. a new method using independent component analysis is proposed in this paper. the - received energy of signals is controlled effectively, thus the near - far effect is overcome as much as possible ; moreover, the effect that noise imposed on the detector is mostly reduced. simulations verify the effectiveness of this method

    傳統檢測器(單用戶匹配濾波)利用擴頻碼之間的互關特性來區分各用戶信號.而在實際應用中,噪聲和近距離用戶對遠距離用戶的強擾即遠近效應,使得接收機的性能受到很大影響.本文將獨立分量分析法引入傳統接收機,有效控制接收信號的能量,從而極大地提高了接收機的抗遠近性能,同時噪聲的影響被盡可能消除.模擬結果表明了該方法的有效性和可行性
  9. The effect of mud on the performence of system can be considered the mud ' s efficience obtained by the link simulation, which depends on the algorithm of the mud, and the system multiplexing factor which depends on all kinds of factors related to the radio propagation environment in the cell network system planning, for example the cell scale, channel model, the system load and the user distribution

    隨后對影響用戶檢測效率的消效率和系統復用因子兩個因素進行了全面而深入的分析。其中前者與接收機採用的mud演算法有關,一般過鏈路模擬得到其結果,後者主要與蜂窩系統規劃設計中各種與環境關的因素有關,如小區尺寸、模型、系統負載、用戶分佈。
  10. Optical code division multiple access ( ocdma ) is a communication mode which introduces the code division multiple access ( cdma ) technology into optical fiber communication system. besides providing asynchronous communications access, ocdma system has many advantages, such as high capacity, security against interception, suppression of narrow band disturbances, capability in forming variable bit rate networks and multi - rate networks. it implies a great challenge for the development of future communication networks, especially all optical networks

    光碼分址( ocdma )是將碼分址( cdma )技術與大容量的光纖信技術結合的一種信方式,其主要優點表現在如下幾個方面:允許個用戶隨機地接入同一:可構成真正「透明」的全光信網路;具有良好的安全性;允許可變速率或速率傳輸,並可同時提供種業務支持;具有優良好的抗擾能力,並能夠充分地利用石英光纖的可用帶寬。
  11. Assigning serial different address code to different subscribers, useful signal is taken out of the same time slot and frequence, and is transmitted with one share channel. at received end, system makes use of completed address code from sending end to do correlative check and take out useful subscriber signal. the other address code signals are treated as broadband disturbing signal which is removed. in radio environment of existing variable disturbtion and muti - way declining, expand frequence signal ’ s broadband characteristics can improve system performance obviously. cdma mobile telecommunication system has some better characteristics, such as anti - disturbing 、 anti - way declining 、 secrecy 、 capacity 、 utilizing rate of frequence resource and so on, than other mobile telecommunication system

    Cdma ( codedivisionmultipleaccess )移動信系統的技術基礎是基於擴頻技術的碼分址,過給不同的用戶分配各自特定的地址碼序列,將處于同時隙和頻率的用戶信號分離開來,採用共享方式傳輸信息。在接收端,系統利用與發送端完全一致的本地地址碼對接收信號進行關檢測,提取需要的用戶信號,而將其他使用不同碼型的信號視為寬帶擾而從中剔除掉。
  12. The closed - form expressions of the detection and false - alarm probabilities and mean acquisition time are derived for the hybrid acquisition scheme with two fixed threshold

    本文分析了在擾下,在衰落中,基於關器解擴的串並混合雙dwell固定門限檢測方案的性能。
  13. From the disser tation, it is noted that smart antenna can effectively deal with mobile communication signals such as coherent signals, non - gaussian signals and multipath signals, etc

    過本文的研究,實現了智能天線對接近現實的信號源、非高斯信號源、經傳輸后等情況下信號的有效處理。
  14. However, multipath components can be resolvable due to the autocorrelation of the spread spectrum signal, thus the optimal receiver equals coherent rake reception, i. e. maximum ratio combining the independent components which endure flat fading or frequency non - selective fading. synchronization of pn code and separation of resolvable multipath components need to estimate the exact time delay among the multipath components

    但是利用擴頻信號的自關特性,可分辨徑可以被有效分離,最優接收機等效為對個具有獨立平坦衰落(或頻率非選擇性)特性的徑信號進行最大比合併,即rake接收。
  15. Finally, the two dimensional flow in the diffuser is calculated, the results show that the change of ma makes an effect to the performance of the diffuser. owing to the accretion of ma, the action of oblique shock waves and the boundary layer pricks up, the flow separates from the wall where the shock waves impinge on the boundary layer more quickly, the cluster of diamond shock waves becomes larger. moreover, by comparing the change of flow field under different structure parameter, it is found that the augment of length of constant area section alter the structure of fluid field little, a smaller area ratio and larger angle of compression section make the diffuser working better

    最後,針對擴壓器中的二維流場進行了數值模擬,結果表明馬赫數對擴壓器性能影響較大,隨著馬赫數的增大,擴壓器管內激波-附面層擾加劇,流動從附面層分離應加劇,激波串數目增;過比較不同結構參數下的擴壓器內流場,發現等直段長度的變化幾乎沒有改變流場結構,只是對局部流場稍有影響,並且在其它參數不變的情況下,一定范圍內減小面積比a2 / a1和增大收縮角有利於擴壓器性能的提高。
  16. The conclusion is made that in the same case, the shannon limit of bfsk based on coherent detection is 3db more than that of bpsk in bsc channel

    過本文的分析可以得到結論,同樣條件下, bfsk信號檢測時的香農限比bpsk信號在bsc模型下的香農限出3db 。
  17. Then the important reference are provided for the optimal system design and technical parameters selecting of long - range underwater acoustic information transmission system. 2. the underwater acoustic channel model based on ray theory is studied, and in combination with the system function of coherent multi - path channel, the method for underwater acoustic channel response prediction through eigenrays finding is obtained

    研究了基於聲線理論的水聲聲場模型,分析並模擬了在種不同聲速條件下的聲線傳播以及不同海底狀況下的聲傳播;結合的系統函數,過求取本徵聲線進行了水聲響應的預測。
  18. 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

    本文研究徑頻率選擇性衰落下直接序列擴頻碼分址( ds - cdma )信號的處理問題,提出了一種新型的盲接收機.該接收機不需預知擾用戶的擴頻碼,不需預知參數,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,該接收機過降維自適應去關濾波和基於判決指導的自適應徑合併,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
  19. Ofdm signals have efficient spectral bandwidth, and the performance of the ofdm system against multipath fading is better than that of the single carrier modulation system

    此項技術具有較高的頻帶利用率,並且與單載波調制技術比可以更為有效的對抗無線中的擾。
  20. 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問題,包括正交變長擴頻序列的關性及其對dscdma系統性能的影響、採用廣義正交( go )序列的載波直接序列碼分址( 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。
分享友人