low-frequency communication 中文意思是什麼

low-frequency communication 解釋
低頻通信
  • low : adj 1 低的；淺的，矮的。 low flight 低飛。 a low temperature 低溫。 low tide [water] 低潮。 The g...
  • frequency : n. 1. 屢次，頻仍，頻繁。2. （脈搏等的）次數，出現率；頻度；【物理學】頻率，周率。
  • communication : n. 1. 通訊，通知；交換；信息；書信，口信，通報。2. 傳達，傳授；傳播；傳染。3. 交通，交通機關；聯系，連絡（設備）。4. 【宗教】接受聖餐。
  1. Frequency - hopping ( fh ) is a novel spread spectrum communication technique, which develops very fast in military field due to its lpi / lpd ( low probability of intercept / detection ) properties and immunity against interferences, the extensive application of hf ( high frequency ) frequency - hopping radios in military has greatly enhanced the ability of military equipments against jamming and interception and brought up a new austere challenge for communication countermeasures

    跳頻通信具有良好的抗干擾性，低截獲概率及組網能力，因此跳頻技術的一出現，便在軍事領域得到了極大的發展，採用跳頻技術的短波電臺在軍事通信中得到了廣泛應用，極大地提高了軍事裝備的抗截獲和抗干擾能力，向通信對抗提出了嚴峻的挑戰。
  2. Digital speech has preponderance over analog speech in reliability, robustness and security during communication. however, digital speech needs more bandwidth than the analog signal. especially with the requirement for communication frequency increasing, it ' s necessary to code speech signal at low rates

    但是，數字化后的信號所佔的頻帶大幅增加，特別是在帶寬需求日益增長的今天，這個問題尤為突出，因此語音的低速率編碼（即壓縮編碼）成為迫切的要求。
  3. With the rapid development of optical fiber communication technology, low - cost and high quality near infrared laser and light emitted diode working at room temperature become widely available. the emit wavelength from these light resource is not only consistent with the three low - decay windows of fiber optics, but also with many wide - frequency or recombination absorption spectrum of environmental and industrial gases

    光纖通信技術的發展使相對低價、工作于常溫、高質量的近紅外激光器和發光二極體可廣泛獲得，這些發光光源的發射波長與光纖的三個低損耗窗口相一致，也與許多環境和工業氣體的泛頻或復合吸收譜線相一致。
  4. With the development of social economy and science technology, rf ( radio frequency ) card technology is more broadly applied by all kinds of trades, specially such as mass transit, wireless communication identify finance trade and safety - defend etc we use usually magnetic card or touch ic ( intelligent card ) in the past, but the shortage is that the card is read - write low efficiency frictional waste and short life, so that it ca n ' t guarantee the reliability of system for long term running

    隨著社會經濟和科技的發展，射頻卡技術越來越廣泛地應用於各種行業，特別是公共交通、無線通信、身份識別、金融交易和安全防衛等行業。過去，智能卡應用領域常採用磁卡或接觸式ic卡，但由於讀寫速度慢，易磨損，使用壽命短，無法保證系統長期運行的可靠性和方便性。
  5. By using optical cable communication methods, which have advantages of great information transmission capacity, rapid velocity, wide frequency band, strong anti - jamming capability, low circuitry loss and easy construction, modern sky - wave over - the - horizontal radar can achieve information transmission and system control of full coherent radar, which has excellent abilities of security, stabilization, anti - jamming and anti - destruction

    通過採用光纖傳輸技術，利用其信息傳輸容量大，速度快，頻帶寬，抗干擾能力強，線路損耗低，易於施工等特點，實現全相參雷達的信息傳輸和系統控制，具有優良的保密性，穩定性、抗干擾性和抗摧毀能力。
  6. The advantages of using leo satellite are as following : on the one hand the satellite orbit is low, so the transmission delay is short, the power loss is small ; on the other hand the development of cell communication, multi - access, frequency multiplex and etc also provide a technique guarantee to the leo satellite - mobile - telecommunication. so the leo system is considered to be a satellite - mobile - communication system with a great future

    低軌道衛星是一種運行於1000公里左右的高空中的人造衛星，利用leo衛星實現個人通信的優點在於：一方面衛星的軌道高度低，使得傳輸延時短、路徑損耗小，多個衛星組成的星座可實現真正的全球覆蓋，頻率復用更有效：另一方面蜂窩通信、多址、點波束、頻率復用等技術的發展也為低軌道衛星移動通信提供了技術保障。
  7. This research about the uhf frequency synthesizer mostly includes the following parts : 1 ) the dds modules include the dds ad9852 part, the lc band pass filter design part, the amplifier design part and lc low pass filter part. 2 ) the pll modules include the design of the loop filter which is the core of pll, lc band pass filter design and the amplifier design. 3 ) the controller modules of the system include the part of pc rs - 232 com port communication with the mcu and the part of the process of controller about urat and mcu

    本課題的研究主要包括以下幾個方面的內容: 1 ） dds模塊設計:包括ad9852部分、 lc帶通濾波器設計部分、放大器設計部分; 2 ） pll模塊設計:包括pll關鍵部件環路濾波器設計、 rflc帶通濾波器設計、末級放大器設計部分; 3 ）控制模塊設計:包括計算機與單片機串口通信的電路設計部分以及程序設計部分。
  8. Molecular mechanism of inhibition of gap junctional intercellular communication induced by extremely low frequency magnetic fields

    極低頻磁場抑制細胞間隙連接通訊的分子機制
  9. In modern microwave and millimeter wave communication systems, the low phase noise frequency sources have the key effects in the systems ’ performance. especially in the national defence, the effects are more obvious. so in this paper, a method to realize the low phase noise x - band frequency source has been proposed, designed, produced and tested

    在現代微波、毫米波通信系統中，低相噪頻率源對系統性能起著非常關鍵的作用，特別是在軍事國防上，這種關鍵的作用更加明顯，為此在本論文中，就如何實現x波段頻率源的低相噪性能，給出了一種設計方法並對其進行了實現。
  10. 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。
  11. With the rapid development of optical fiber communication technology, low - cost and high quality near inferred laser and light emitted diode working at room temperature become widely available. the emit wavelength from these light resource is not only consistent with the three low - decay windows of fiber optics, but also with many wide - frequency or recombination absorption spectrum of environmental and industrial gases

    光纖通信技術的發展使相對低價、工作于常溫、高質量的近紅外激光和發光二極體可廣泛獲得，這些發光光源的發射波長與光纖的三個低損耗窗口相一致，也與許多環境和工業氣體的泛頻或復合吸收譜線相一致。
  12. Code - division multiple - access ( cdma ) technology has become the main technology studied in the personal communication service ( pcs ) recently because it has lots of benefits, such as large system content, high voice quality, easy frequency scheme, low cost of the net making and so on

    碼分多址技術因其具有系統容量大、語音質量高、頻率規劃簡單、建網成本較低等眾多優點，已成為近年來個人通信業務中研究的主要技術。
  13. Cdma ( code division multiple access ) is a promising technology for future mobile communication system because of its several features with which other multiple access technology can not compare : higher efficiency of frequency allocation, robust anti - multipath effect, macro diversity, mitigating interference, soft capacity, low power, soft handoff, simple frequency design, easy access, and so on

    碼分多址接入（ cdma : codedivisionmultipleaccess ）方式以頻譜利用率高、抗多徑、抗干擾、軟容量、低功率、軟切換、宏分集、頻率規劃簡單、用戶接入方便等其它多址技術不可比擬的優越性被認為是未來移動通信系統的理想接入技術之一。
  14. In recent years, because new operation such as video phone and video frequency conference came forth, low rate video communication has been used widely

    近幾年來，新出現和即將出現的視頻業務（如可視電話、視頻會議） ，使低碼率視頻通信得到廣泛的應用。
  15. For medium or long distance underwater acoustic communication, the narrow bandwidth and low carrier frequency only supports low bit - rate signal transmission

    對于中、遠距離的水聲通信而言，水聲通道的窄帶寬、低載波頻率特性只能支持較低的信息傳輸速率。
  16. Frequency - hopping ( fh ) is a novel spread spectrum communication technique, which develops very fast in military field due to its lpi / lpd ( low probability of intercept / detection ) properties and immunity against interferences, the extensive application of hf / vhf ( high frequency / very high frequency ) frequency - hopping radios in military has greatly enhanced the ability of military equipments against jamming and interception and ensure the safety and validity of chain of military command

    跳頻技術是擴頻技術的一種，是80年代以來出現的一種新的通信方式。跳頻通信具有良好的抗干擾性，低截獲概率及組網能力，因此跳頻技術的一出現，便在軍事領域得到了極大的發展。採用跳頻技術的短波超短波電臺在軍事通信中得到了廣泛應用，極大地提高了軍事裝備的抗截獲和抗干擾能力，保證了軍事指揮系統的安全和有效性。
  17. The c / s pattern can be used in the limited - ranged operations which are characterized by high security, high frequency of data processing, heavy transmission of data, good mutual - communication and fixed - places, such as the input and maintenance of graduate information, the management of code table, data backup and recovery. whereas, the b / s pattern can be used in the wide - ranged operations, which are characterized by low security requirement and mutual - communication, and flexible places, such as the release of requirement, the query of graduate information, on - line registration of graduate data and all kinds of query and statistic

    在安全性要求高、數據處理頻繁、數據傳輸量大，交互性強、地點固定的小范圍內的業務，如畢業生信息錄入及維護、代碼表管理、數據備份和恢復等模塊採用c s模式實現；而在安全性和交互性要求不高、地點靈活的廣域范圍內的業務，如需求信息發布、生源信息查詢、畢業生詳細資料在線登記和各種查詢、統計等模塊採用b s模式。
  18. This system realizes the underwater distance mobile security communication. the only shortage is the low velocity, which is result from the speciality of underwater channel and that spread spectrum need big frequency band

    採用這一技術的水聲通信實驗系統成功的進行了湖上試驗，這種技術的不足是通信速率較低，這是由於水聲通道的特殊性以及擴頻技術要佔用大量帶寬所致。
  19. The technology of very low bit rate for hf ( high frequency ) communication means that, one technology of ecm ( electronic counter measures ) resistant communication is developed for low bit data message exchange in the time of battle which data communication is destroyed by electronic disturber. it is regarded by armies in the battle of information, because that it can overcome the very low snr ( signal noise ratio ), very high narrow - band interference and multipath with maxium delay of fifty millisecond

    短波最低限度通信技術是在戰時強電磁干擾情況下能實現保證最低限度的數據報通信的一種抗干擾通信技術。由於其能有效的克服極低信噪比、較強的窄帶干擾和幾十毫秒的多徑，在信息戰中受到各軍高度重視。
  20. Now the development in radio communication system and sensors productively need saw devices of high performance and high frequency. but electromagnetic interference of saw device is evident day and day. so the saw device technologies of the electromagnetic interference and electromagnetic compatibility in its process of design, fabrication and production must be considered. the demand request saw designer of second order effects which are not considered in low frequency

    當前在無線通信系統和傳感器方面的進展預示了需要高性能、高頻的saw器件，但是隨著其工作頻率的提高， saw器件電磁干擾問題日益突出，因此saw其電磁兼容技術在設計、研製和生產過程中是必須考慮的。
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