narrow-band system 中文意思是什麼
narrow-band system
解釋
窄帶制-
In this system two oscillator are used for mixing. pll for high local oscillator and dds + pll for low local oscillator. by making full use of favourable narrow - band tracing filter character of pll and by combining the merits of dds such as super fine frequency resolution, high frequency accuracy, very fast frequency hoping with it, the pll / pll + dds frequency synthesizer presents wide band high quality source and super small frequency hoping step
系統採用兩次混頻，其中高本振的設計採用pll鎖相環頻率合成來實現，充分發揮了鎖相環頻率合成器的優良特性，實現了系統所要求的高質量寬頻帶本振源；低本振採用pll + dds頻率合成來實現，結合pll優良的鎖相特性與dds的高頻率解析度、高頻率精確度等優點，實現了頻率的小步進高精度合成。 -
Experiments show that, when use msp430f149 audio sensor to identify vehicles that contain plane, tank, truck and so on by time domain features and two - level f - ratio, the recognition rate is 82. 1 % ; when use both msp430f149 audio sensor and arm9 sensor to identify vehicles, and the recognition rate is much better than the original system and msp430f149 audio sensor. line spectrum of power spectra and 3 / 2 spectrum is used as frequency features on arm9 sensor, and it is caught by narrow - band bandpass filter
實驗證明，在主頻為8mhz的msp430f149感知器上，採用基於時域特徵和二階f比的識別演算法，能夠實時地完成對飛機、坦克、卡車等交通工具的識別;將msp430f149感知器與基於arm9的高端感知器配合使用，且高端感知器採用功率譜線譜或3 / 2維譜線譜作為頻域識別特徵，能夠實時的對各類交通工具做更高性能的識別。 -
Frequency response, quantization noise, reconstruction error and its sensitivity to mismatch among adcs are studied at length in prqmf banks adc system, and the theoretic results include : ( 1 ) the distortion / aliasing functions of hybrid filter banks adc system is similar with that of switch capacitor filter banks adc system ; ( 2 ) for wide or narrow band input signal, the effective resolution of the two adc systems is 0. 51og2m bits higher than their adc ; ( 3 ) reconstruction error ' s sensitivity to mismatch among adcs of the two adc systems is reduced effectively than time interleaved adc system
2對prqmf濾波器組adc系統的頻響、量化噪聲特性、重建誤差特性以及重建誤差對adc間的失配敏感性進行了理論分析研究，所得到的理論結果為： （ 1 ）混合濾波器組adc系統與開關電容濾波器組adc系統的失真/混迭函數一致； （ 2 ）無論輸入寬帶還是窄帶信號，這兩種adc系統的有效解析度均比其adc提高了0 . 5log _ 2m比特； （ 3 ）這兩種adc系統的重建誤差對其adc間的失配敏感性均明顯低於時間交織adc系統。 -
The thermovision 2000s long - wave, narrow band qwip 320 x 240 fpa delivers high thermal sensitivity in both warm and cold climates and makes the system resistant to existing laser
Thermovision 2000採用320 x 240像素長波窄波段的焦平面的探測器。在溫暖和寒冷的天氣下具有很高的熱靈敏度，確保系統能夠抵抗現有的激光攻擊性武器。 -
To reproduce the narrow - band response, based on the thought of kanamori etc., the damping ratio and natural period are modified. through this adjustment, the narrow - band response can be reproduced, but for some natural periods the adjustive damping ratio has become negative. the negative damping is strange and can not be explained by the equation of motion for sdof system
為了生成窄頻帶反應，本文根據kanamori等人的方法調整了計算時的阻尼比及自振周期，調整后的單邊差分方法能在共振區域生成很好的窄頻帶反應，但是對一些周期點的阻尼比調整成為了負值，這從系統的動力平衡方程是難以解釋的。 -
Effect of error auto - compensation and error of the extremely narrow - band interference filter in dwdm system
Dwdm極窄帶干涉濾光片的誤差與自動補償效應 -
Abstract : the threshold algorithm of the target detection is often used to detect target echo signals. its performance is based on signals - noise ratio. when signals - noise ratio is great than 6. 7, the target can be detected. in order to increase the signals - noise ratio, matching filter is often used. if the system is narrow band system, the noise is color noise and matching filter cannot be used. therefore, the signals - noise ratio cannot be increased. however, the geometrical characteristic of the laser echo signal is different with the noise. this paper advises the algorithm that detects the target by the geometrical characteristic. when signals - noise ratio is great than 2, this algorithm can detect target. this algorithm has been used in practice
文摘:目標檢測的閾值法經常用於檢測目標的回波信號.它的性能取決于信噪比，當信噪比大於6 . 7時，能夠檢測出目標.為了提高信噪比，經常採用匹配濾波器.如果系統是窄帶系統，噪聲為色噪聲，無法使用匹配濾波器，不能提高信噪比.激光回波信號的幾何特徵不同於噪聲.提出了一種利用這種幾何特徵檢測目標的演算法.當信噪比大於2時，該演算法能夠檢測出目標.該演算法已經實際應用 -
The demodulation method of fiber grating is the key method of fiber grating sensor. the main demodulation method includes : grating matching method, tunable fabry - perot cavity method, non - balance mach - zehnder interferometer method and tunable narrow - band light source method. the tunable fabry - perot cavity method is discussed in detail, and a demodulation system based on dsp is put forward
光纖光柵的解調技術是光纖光柵傳感器的關鍵技術，本文討論了光纖光柵的波長解調方法，包括匹配光柵法、可調諧f - p腔法、非平衡mach - zehnder干涉儀法和可調諧光源法等，詳細分析了可調諧f - p濾波器的特性和解調原理提出了一種基於dsp的解調光纖光柵波長的可調諧法布里一珀羅腔解調方案。 -
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
光碼分多址（ ocdma ）是將碼分多址（ cdma ）技術與大容量的光纖通信技術相結合的一種通信方式，其主要優點表現在如下幾個方面：允許多個用戶隨機地接入同一通道：可構成真正「透明」的全光通信網路；具有良好的安全性；允許可變速率或多速率傳輸，並可同時提供多種業務支持；具有優良好的抗干擾能力，並能夠充分地利用石英光纖的可用帶寬。 -
Current transformers are nonreplaceable in the field of protection and measurement for decades, but the electromagnetic current transformers can not meet the development of the electric power system for the reasons of magnetic saturation, ferro resonance, little dynamic range, narrow service band and so on 。 with the popularization of microcompute, it will be irreversible to apply microcompute in the protection and measurement, the equipments do not need the current transformer with high power, so the rogowski coil can apply on the field of protection and measurement
電流互感器在繼電保護和電流測量中的作用長期以來具有不可替代的地位，但電磁式電流互感器所固有的磁飽和、鐵磁諧振、動態范圍小、使用頻帶窄等都難以滿足電力系統發展的要求。隨著微機的普及，在繼電保護和測量中應用微機已是不可逆轉的潮流，設備已不再需要高功率輸出的電流互感器，因此可以選用rogowski線圈作為低電壓輸出要求的電流測量和繼電保護應用。 -
The spread spectrum ( ss ) communication system has stronger ability of resisting jamming, narrow band, and multipath interference than that of the conservation communication systems
擴頻通信系統與常規的通信系統相比，具有很強的抗人為干擾，抗窄帶干擾，抗多徑干擾的能力。 -
The main contents of the dissertation are as follows : chapter one summarizes the situation and application of response in nonlinear dynamical system under narrow - band random excitation and presents the main contents and arrangement of the dissertation
第二章和第三章研究了系統（ 1 1 ）在窄帶隨機外部激勵下的共振響應問題。主要討論了w _ 2 3w _ 1 ， 3w _ 1時的情況。 -
There are several defects of the monitoring method using embedded optical fiber sensors, such as the narrow frequency operation band of the sensors and the expensive cost of the instrument system
光纖傳感法也存在著不少缺點，如光纖頻帶窄、設備費用昂貴等。 -
In the highly crowded hf band, available continuous bandwidth is very narrow, this threaten the viability of hf radar based on the continuous spectra signal system seriously
在擁擠的高頻頻段，可用的連續帶寬比較窄，基於連續譜信號體制的高頻雷達的生存能力受到嚴重威脅。 -
Scheme iii. a system combining fft algorithm with chirp - z transform to detect feedback rapidly and accurately. then, adopting a filter bank composed of 12 iir narrow - band notch filters to eliminate feedback
採用chirp - z變換（ czt ）演算法與fft演算法相結合對聲反饋進行檢測，使用由12個iir窄帶陷波器構成的濾波器組對聲反饋進行抑制。 -
This task uses the ds - ss technology, and researchs the important technologies, such as synchronization of ds - ss, rake receive, narrow - band interference suppression, etc. these technology are useful for the voice - band channel of hf. i designed one system of very low bit rate for hf data communication, and completed the softwave module design of the system. i get the result of system ' s simulator, it ' s useful for the system realization
根據短波音頻帶寬通道的特點，重點對系統的擴頻同步技術、 rake接收技術和窄帶抗干擾技術進行了專題的研究。並根據自己多年的科研經驗，設計了一種具有實際意義的短波最低限度通信系統，並對實際的軟體實現進行了模塊化的設計。 -
In consideration of defects of weak anti - interference ability of strong - narrow band in an orthomode spread spectrum system, it is proposed that an ablefaction auto - adated filter, which is a new method, is used to trace and avoid the interference from the strong - narrow band
摘要針對直擴系統對強窄帶干擾的抗干擾能力弱的缺陷，提出了採用白化自適應濾波器來跟蹤並消除強窄帶干擾的新方法。
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