線路傳輸頻譜 的英文怎麼說
中文拼音 [xiànlùzhuànshūbīnpǔ]
線路傳輸頻譜
英文
line transmission frequency spectrum- 線 : 名詞1 (用絲、棉、金屬等製成的細長的東西) thread; string; wire 2 [數學] (一個點任意移動所構成的...
- 路 : 1 (道路) road; way; path 2 (路程) journey; distance 3 (途徑; 門路) way; means 4 (條理) se...
- 傳 : 傳名詞1 (解釋經文的著作) commentaries on classics 2 (傳記) biography 3 (敘述歷史故事的作品)...
- 輸 : Ⅰ動詞1 (運輸; 運送) transport; convey 2 [書面語] (捐獻) contribute money; donate 3 (失敗) l...
- 頻 : Ⅰ形容詞(次數多) frequent Ⅱ副詞(屢次) frequently; repeatedly Ⅲ名詞1 [物理學] (物體每秒鐘振動...
- 譜 : Ⅰ名詞[書面語]1 (按類別或系統編成的書或冊子等) table; chart; register 2 (指導練習的格式或圖形)...
- 線路 : 1. [電學] circuit; line 2. [交通運輸] line; route
- 頻譜 : frequency spectrum; frequency content; spectrum; power density spectrum; power spectrum; [系統] s...
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This paper mainly focuses on the noise limiting by means of the direct sequence spread spectrum ( dsss ) and the analysis of the transmission performance of the plc and some digital modulation technology. the contents of the paper is as follows : 1 ) the technical feasibility is proved after simulating noise limiting principle of dsss by means of systemview, the simulation software ; 2 ) a kind of band pass filter ( bpf ) is realized according to the requirement of filter and the principle of butterworth approximation, which satisfies the index of performance of dsss. 3 ) the low voltage plc system includes the sc1128, the specific modulation / demodulation ic, the bpf filter and other circuit components, furthermore, the control function of system is realized by means of the personal computer and the microcontroller
本課題在對低壓電力線的傳輸特性和數字調制技術進行分析的基礎上,將通信理論中的直接序列擴頻技術( dsss )用於解決低壓電力線通信的干擾問題,主要研究內容如下: ( 1 )用通信模擬軟體systemview對dsss技術的通信和抗干擾原理進行模擬分析,分別對時域和頻域下採用dsss技術前後接收信號的頻譜進行分析,驗證dsss技術在本系統中的可行性; ( 2 )由dsss技術對濾波系統的要求,根據濾波理論分析了巴特沃思型濾波器的逼近原理並設計了合適的濾波電路; ( 3 )用調制解調晶元sc1128和自行設計的濾波器加之輔助外圍電路,構造出低壓電力線載波通信系統,並採用atmel公司的單片機設計了接收和發射電路的微控制器; ( 4 )分別對採取抗干擾措施前後輸入和輸出信號進行對比實驗,並對結果進行分析,驗證了dsss技術對干擾信號的抑制作用。This article takes hanging off and wide fluctuation of transmition velocity of adsl as example, then analysis centers on the discerte multiple tone and the principle of channel load assignation. from analysis above article points out the root of adsl being sensible of noise signal. at last, reserches effects that window function and barrier effect on frequency and adopts fft to work out the noise power of adsl
本文以電信現在推出的adsl傳輸中鏈路經常掉線和傳輸速率經常大范圍波動為例,重點分析了adsl所使用的dmt調制方式和注水演算法分配通道載荷方式原理,由此指出adsl對噪聲信號敏感的根源,在得到問題的根源之後,分析了窗函數和柵欄效應對頻譜的影響,採用fft方法計算adsl線路的噪聲功率譜,為adsl線路測試提供了可靠的理論依據。For recent years, adsl has world widely employed and widely used in many aspects such as vod, remote medical treatment and e - shopping etc. but we noticed that the traditional telephone networks are designed for the transmission of low frequency signals, and the adsl ' s frequency rang is from 0 to 1. 104mhz, so we must confront the signal attenuation, the loop line noise impairments, the crosstalk interferences, the bridge tap reflections and the rf disturbances problems and many other problems when transmitting the adsl signals one the telephone networks
近幾年來, adsl在世界范圍內得到充分的使用,廣泛應用於視頻點播、遠程醫療、網上購物等各個方面。但是由於電話線網路是專門為傳輸低頻信號而設計,而adsl的頻譜范圍在0 1 . 104mhz內,因此在傳輸adsl信號時,面臨著信號衰減、線路噪聲、串音干擾、橋接抽頭反射和射頻干擾等等多方面的問題,這就要求在adsl開通之前對線路進行一系列的測試。Martin meyer, a pianist from edmonton has been invited to perform at the food promotion in hsinchu royal hotel. he will be performing during the period of the promotion. for more information on the promotion, please contact the hotel royal hsinchu tel : 5631285 or visit their website at
此wimax網路由北電將提供固定式wimax 802 . 16d基地臺室內與室外用戶終端設備customer premises equipment cpes與無線傳輸線設備,以3 . 5ghz頻譜運作,同時協助安裝及提供專業服務。This thesis adopts 8psk / qpsk modulation mode that ' s widely applied in short - wave communication to research all - digital blind receiver in burst mode based on software radio technology. then related solutions are given for the doppler frequency shift problem and multiple fading problem in short - wave channels. the arrangement of the thesis is below : chapter 1 gives brief description for the new technology and new systems of short - wave communication and for the development and appliance of software radio
本文採用短波通信中應用廣泛的8psk qpsk調制方式,研究基於軟體無線電技術的突發模式全數字盲接收機,並對多音并行及慢速傳輸中存在的多譜勒大頻偏問題、單音串列、高速數傳時在短波通信鏈路中發生的干涉衰落問題做了研究,提出了相應的解決方案。Recently, multiple input multiple output ( mimo ) system which originates from the employment of multiple antennas at transmitter and receiver has many advantages such as large system capacity, high spectral efficiency. on the other hand, orthogonal frequency division multiplexing ( ofdm ) which bases on the orthogonal transmission of sub - carriers also has some obvious merits such as strong anti - multipath ability, high spectral efficiency. the combination of the two techniques mimo - ofdm, has become a hotspot recently and regarded as promising technique for future next - generation mobile communication systems
近來,在無線通信系統中的收發兩端同時使用多根天線的多入多出( mimo , multiple - input - multiple - output )通信結構,具有系統容量大、頻譜效率高等優點;基於正交的多路子載波并行傳輸的正交頻分復用( ofdm , orthogonalfrequencydivisionmultiplexing )技術,具有抗多徑能力強、頻譜效率高等優點,二者的結合,即mimo - ofdm技術,被認為是構建下一代移動通信系統的框架技術。分享友人