衰落頻譜 的英文怎麼說

中文拼音 [shuāilàbīnpǔ]
衰落頻譜 英文
fading ectrum
  • 衰 : 衰動詞（衰弱） decline; wane
  • 落 : 落名詞[方言] （北方對蓮花落的俗稱） a kind of folk song
  • 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）...
  • 衰落 : decline; be on the wane; go downhill; fading; decay; decaying; lapse; erode
  • 頻譜 : frequency spectrum; frequency content; spectrum; power density spectrum; power spectrum; [系統] s...
  1. And then facing the problem of the channel estimation of the adaptive modulation system, we conclude out the channel estimation algorithms on maximum likelihood ( ml ) estimation and maximum a posteriori ( map ) estimation under the condition of flat fading channel and selective fading channel in detail. to meet flat fading channel, we simulate the relationship of the ratio between the error covariance in map estimation and ml estimation and pilot symbol message length. the conclusion can be drawn from these results

    接著，對自適應調制系統中的通道估計問題難點，詳細推導了平衰落通道條件下和選擇性衰落通道條件下最大似然（ ml ）估計和最大后驗概率（ map ）估計演算法，針對平衰落通道，我們模擬了map估計和ml估計的方差與導頻符號長度的關系，模擬結果表明，錯誤方差受多譜勒頻率的變化影響最大，並且對實際的自適應調制系統，導頻符號長度的取值超過20個符號長度時， map通道估計明顯優于ml通道估計。
  2. In this thesis, for the merits of high frequency spectrum utility factor and high - speed data communication, the ofdm is introduced into the underwater acoustic communication. combined with fec to combat the frequency - selective fades and isi in the underwater acoustic channel, high speed data transmission is realized by employing ofdm technology

    本研究嘗試將ofdm技術引入水聲通信領域，利用該技術頻譜利用率高，多載波并行傳送的特點，結合通道編碼，以克服水聲通道多徑干擾引起的頻率選擇性衰落和碼間干擾，獲得高速率數據傳輸。
  3. On the other hand, cdma ( code - division multiple access ) communication system has been widely considered as the mainstream of 3g communication system, because it has the good qualities such as high utilization ratio of frequency band, low transmission power, powerful anti - multiple path falling and flexible capacity

    另一方面， cdma通信系統以其高頻譜利用率、低發射功率、強抗多徑衰落特性、軟容量等優點，已被廣泛認為是第三代移動通信系統的主流。
  4. The simulation results based on siso and mimo systems show that the proposed scheme could effectively eliminate the time - variant fading characteristics of wireless channel and under an acceptable demand of ber, the frequency efficiency is enhanced greatly and besides, dynamic encoding is implemented with low complexity and high efficiency

    通過在單天線和多天線系統中的模擬，表明該方案可以有效的克服無線通道的時變衰落特性，在滿足誤碼率性能要求的基礎上可以提高系統頻譜利用率，且實現復雜度低。
  5. In mimo systems, the signal can be sent and received through multiple antennas or antenna arrays. the combination of ofdm and mimo can effectively alleviate the problem of multi - path propagation, increase system capacity, and obtain more robust system capability, so they are considered as the main stream techniques of the future wireless communication system

    Ofdm技術固有的抗通道多徑和頻率選擇性衰落特性以及mimo在提高系統頻譜利用率，改善無線通信系統性能等方面的巨大作用，使得這兩種技術的融合成為了下一代移動通信系統的必然選擇。
  6. Ofdm, with the advantage of high spectrum efficiency and easy realization, can strongly combat multi - path and dispersive channel interference, so its application is remarkable in recent years

    正交頻分復用（ ofdm ）技術具有抗多徑時延、抗通道衰落、頻譜利用率高、硬體實現簡單等優點，近年來受到廣泛關注。
  7. Spread spectrum technique, which can handle variable adverse environments, exhibits unique qualities that have a number of advantages in anti - jamming, anti - noise, reduction of multi - path interference, low power spectral density, privacy, selective addressing and code division multiplexing

    擴頻通信技術具有優越的抗干擾、抗噪音、抗多徑衰落性能，能在低功率譜密度下工作，具保密性、可多址復用和任意選址，能有效克服各種惡劣的通道特性，目前廣泛應用於移動通信、雷達、導航、測距、電力線通信等領域。
  8. 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。
  9. Furthermore, it become more and more important in commercial wireless communication because it can reduce the effects imposed by multi - path fading and co - channel interference

    另外，跳頻通信也應用到民用通信中以抗衰落、抗多徑、抗網間干擾和提高頻譜利用率。
  10. And the orthogonal frequency division multiplexing ( ofdm ) is given more and more attention in wireless area, because ofdm lessens the severe effects of frequency selective fading and improves the spectrum efficiency, and this technology has been indicated to become a key technology in the fourth moving communication

    其中ieee802 . 11a協議中使用到的ofdm （正交頻分復用）技術，由於其先天具有抗多徑衰落及頻譜使用率高等特性，成為當代無線通信領域研究的熱點，並預示著為第四代移動通信的關鍵技術。
分享友人
分享到 Line

分享到臉書