at random 任意,隨便; 任意地,隨機(jī)地; 隨便地,任意地; 隨機(jī)的,任意的; 隨機(jī)地,任意地; 隨意地,任意地; 隨意地,隨機(jī)地
random n. 〔罕用語〕胡亂行為,偶然的[隨便的]行動[過程]。 adj. 1.任意的,胡亂的,隨便的;(話等)信口亂說的;(人等)偶然碰到的。 2.隨機(jī)的;【物理學(xué)】無規(guī)則的;(石工)(大小)不齊的。 a random guess 瞎猜。 a random shot 亂射(的子彈);流彈。 at random 碰運(yùn)氣地;無目標(biāo)地,漫無目的地。 n. -icity 隨機(jī)性,無規(guī)性。
code n. 1.法典;法規(guī)。 2.規(guī)則,準(zhǔn)則;(社會、階級等的)慣例,習(xí)俗,制度。 3.(電)碼,代碼,密碼,暗碼;代號,略號,暗號。 4.【生物學(xué)】遺傳(密)碼。 the civil [criminal] code民[刑]法典。 the moral code道德準(zhǔn)則。 code of signals 信號密碼(本)。 code of the school 校規(guī)。 code and conventions 規(guī)章制度。 C- Napoléon 拿破侖法典。 C- of Hammurabi (古代巴比倫的)漢穆拉比法典。 code of honour 社會禮法;決斗慣例。 code of written law 成文法典。 the International Code 國際電碼。 the Morse code 摩爾斯電碼。 vt. 1.把…編成法典[法規(guī)]。 2.把…譯成[編成]電碼;編(碼);譯(碼)。 n. -r 【自動化】編碼裝置;【電訊】記發(fā)器。
This paper focus on these problems and discusses the possibility of using pseudo-random code phase modulated ( prcpm ) technology in measuring high speed target . at first the basic principle of the m series is given, then a doppler pretreatment method is given 首先介紹了m序列編碼基本理論,然后給出了m序列調(diào)相雷達(dá)多普勒預(yù)處理的方法,該方法充分利用了m序列的移位相乘后仍為m序列的特性,并且將該方法擴(kuò)展到一般的二相碼序列。
2, studying the character of the output of the laser used on the practical qkd system, and design and made a photo-electronic detection circuit to accomplish the necessary photo ? electronic conversion for the practical qkd system . 3, designed two balance true random codes generators for qkd system, they are based on physical random source . and analyzed randomicity of the generators 三、設(shè)計制作了量子保密通信用的真隨機(jī)碼發(fā)生器,先后制成了兩臺樣機(jī),一臺采用窄帶隨機(jī)信號源,一臺采用寬帶隨機(jī)源,并研究了隨機(jī)源對隨機(jī)碼的隨機(jī)性的影響,最后進(jìn)行了隨機(jī)性的分析。
Turbo codes were presented by c . berrou in international conference on communications in 1993 . they hang convolutional code and random interleaver together to realize the idea of random coding, and adopt soft input / soft output ( siso ) iterated decoding to approach maximum likelihood decoding ( mld ) . turbo codes come closer to approaching shannon's limit turbo碼,由c.berrou等在icc’93會議上提出,它巧妙地將卷積碼和隨機(jī)交織器結(jié)合在一起,實(shí)現(xiàn)了隨機(jī)編碼的思想,同時,采用軟輸入軟輸出迭代譯碼來逼近最大似然譯碼,具有近shannon限的性能。
This thesis presents the acquisition method of synchronization codes and time mark codes under-20db gaussian channel . then the total step length between initial state and current state can be calculated . basing on the step length, we can deduce the current state of pseudo-random codes, and implement the acquisition of the special pseudo-random codes 本文設(shè)計出時間標(biāo)記碼在信噪比達(dá)-20dd時的捕獲方案,在此基礎(chǔ)上提出了由偽碼歷經(jīng)的狀態(tài)數(shù),計算子碼當(dāng)前狀態(tài)的方法,從而獲得了在30秒內(nèi)完成導(dǎo)航定位衛(wèi)星信號直接捕獲的方法與實(shí)現(xiàn)方案。
This thesis presents the acquisition method of synchronization codes and time mark codes under-20db gaussian channel . then the total step length between initial state and current state can be calculated . basing on the step length, we can deduce the current state of pseudo-random codes, and implement the acquisition of the special pseudo-random codes 本文設(shè)計出時間標(biāo)記碼在信噪比達(dá)-20dd時的捕獲方案,在此基礎(chǔ)上提出了由偽碼歷經(jīng)的狀態(tài)數(shù),計算子碼當(dāng)前狀態(tài)的方法,從而獲得了在30秒內(nèi)完成導(dǎo)航定位衛(wèi)星信號直接捕獲的方法與實(shí)現(xiàn)方案。
This dissertation adopts a universal digital ds / dmpsk modulation and demodulation scheme which is based on fpga . this scheme adopts quadrature balanceable modulation, intermediate frequency sampling, digital matched filtering, delay differential demodulation techniques and so on . it directly processes the digital signals on intermediate frequency without down-conversion, and doesn ’ t need pseudo random codes synchronization and carrier wave extraction circuits 本文采用了一種基于fpga的通用數(shù)字調(diào)制解調(diào)方案,該方案在調(diào)制端采用了正交平衡調(diào)制技術(shù),在解調(diào)端采用了中頻帶通采樣、數(shù)字匹配濾波、延時差分解調(diào)等技術(shù),直接在中頻上進(jìn)行數(shù)字信號處理,不需要進(jìn)行下變頻,也不需要增加額外的偽隨機(jī)碼同步捕獲和載波提取電路。
The thesis originally shows a new second-frame structure, which is made up of the synchronization codes, time mark codes and pseudo-random codes, also brings out the spread spectrum method for the synchronization codes and time mark codes and the analysis of the correlation and security of the pieces of the pseudo-random codes in the satellite signal 本文設(shè)計出了“前導(dǎo)碼?時間標(biāo)記碼?偽隨機(jī)碼”的信號秒幀結(jié)構(gòu),提出了前導(dǎo)碼和時間標(biāo)記碼的gold碼擴(kuò)頻方案,以及偽隨機(jī)碼的生成方案,在此基礎(chǔ)上分析了偽碼的相關(guān)性和安全性。
The thesis originally shows a new second-frame structure, which is made up of the synchronization codes, time mark codes and pseudo-random codes, also brings out the spread spectrum method for the synchronization codes and time mark codes and the analysis of the correlation and security of the pieces of the pseudo-random codes in the satellite signal 本文設(shè)計出了“前導(dǎo)碼?時間標(biāo)記碼?偽隨機(jī)碼”的信號秒幀結(jié)構(gòu),提出了前導(dǎo)碼和時間標(biāo)記碼的gold碼擴(kuò)頻方案,以及偽隨機(jī)碼的生成方案,在此基礎(chǔ)上分析了偽碼的相關(guān)性和安全性。