頻移失真 的英文怎麼說
中文拼音 [bīnyíshīzhēn]
頻移失真
英文
deviation distortion-
And pays emphasis on analyzing the system structure and system flow, the core techniques, the channel characteristic and parameters of dvb - t system. the system adopts some core techniques such as cofdm, a lot of tps ( transmission parameter signalling ) insert and guard interval, and so on. so it can withstand high - level ( up to odb ), long delay static and dynamic multipath distortion
論文首先描述了數字電視地面廣播的需求條件，技術難點和目前存在的問題，並重點分析了dvb - t系統結構流程，核心技術及系統通道特性和參數，該系統採用了cofdm （編碼正交頻分多路復用） ，大量導頻信號插入和保護間隔技術等核心技術，使之能抵抗高電平（ 0db ） ，長延時的靜態和動態多徑失真，有利於數字和模擬電視的混合傳輸，它的多載波調制模式功能和性能在移動和便攜接收、同頻網等方面具有獨特的優勢。On the following, on the basis of formulas given above, three kinds of effects due to ionosphere are presented : image shift due to group delay which was caused by the difference between the group velocity and the velocity of light in the ionosphere ; image distortion due to ionospheric dispersion which can create second phase error of lfm signals ; the last, the phase perturbation caused by the irregularities of the ionosphere can reduce the coherent length and affect azimuthal resolution
文中主要研究了電離層的三種影響：信號經過電離層傳播的群延遲引起的成像偏移；電離層的色散效應給線性調頻信號帶來二次相位誤差，導致圖像退化、失真；以及電離層的閃爍、湍流等不規則性引起的信號相位起伏。在此基礎上，比較分析了不同波段、帶寬條件下電離層的影響。The time base drift deduced by the change of temperature is discussed particularly and the compensation method of it is analyzed. finally, we also studied frequency band extension under time base distortion condition by simulation. the results show that the compensation of time base distortion can reduce the error of signal and then increase the accuracy of frequency band extension
首先，介紹時基失真的相關概念及其對測量信號的影響；其次，對時基失真特性測量的不同方法進行了理論分析和比較，並對分析信號法進行了模擬研究；再次，對時基失真的補償方法進行分析和模擬研究；並專門對溫度變化引起的時基漂移及其補償方法進行了簡要分析；最後，對時基失真條件下的頻帶展寬技術的模擬表明時基失真的補償可以減小信號的誤差，因而提高頻帶展寬的精度。This encoding mode was first applied in digital mobile communications to encode voice, effectively lessening the code distortion of audio signals
該編碼首先應用在數字移動通信中，用作話音的編碼，它能夠有效地削減音頻信號的編碼失真。Multi - path fading and doppler shift of wireless mobile channels would generate interference to signals, as a result, waveform of the received signal would be distorted, and channels would be interrupted if the interference is severe
無線移動通道的多徑衰落和多普勒頻移會對信號產生干擾，導致接收信號波形失真，嚴重者會造成通信的中斷。分享友人