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基于Android的校园二手商品交易系统的设计与实现
基于Android的校园二手商品交易系统的设计与实现
- 2020-11-03下载
- 积分：1
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RTCM3.3协议全
全新RTCM3.3协议完整版RTCM STANDARD 10403.3DIFFERENTIAL GNSS(GLOBAL NAVIGATION SATELLITE SYSTEMS)SERVICES – VERSION 3DEVELOPED BYRTCM SPECIAL COMMITTEE NO. 104OCTOBER 7, 2016COPYRIGHT©2016 RTCMRadio Technical Commission for Maritime Services1611 N. Kent St., Suite 605Arlington, Virginia 22209-214RTCM Paper 141-2016-SC104-STD000ocRTCMco00c30RTCM 10403. 3, Differential GNSS Global Navigation Satellite Systems)Services- Version 3, October 7, 2016This standard (referred to as version 3 has been developed by rtCm special Committee 104 as a moreefficient alternative to the standards entitled rtcm recommended standards for diffe rentialRecommended Standards for Differential gNss Global Navigation Satellite Systems Service, Version 2.x(Current version is 2. 3, now designated as RTCM 10402. 3. Service providers and vendors represented onthe SC104 Committee wanted a new standard that would be more efficient, easy to use, and more easilyadaptable to new situations. The main complaint was that the version 2. x parity scheme, which useswords with 24 bits of data followed by 6 bits of parity, was wasteful of bandwidth. Another complaint wasthat the parity was not independent from word to word. Still another was that even with so many bitsdevoted to parity the actual integrity of the message was not as high as it should be. Plus, 30-bit wordsare awkward to handle. the new standard version 3 is intended to correct these weaknessesUnlike Version 2. x, this standard does not include tentative messages The messages in Version 3 haveundergone testing for validity and interoperability and are considered to be permanent. amendments tothe standard may change the meaning of reserved bits or provide additional clarifying text, but no changeswill be made in the data fields. Changes will require new messages to be developed. In addition to themessages described in the current standard the committee continues to develop new messages whichare described in separately published amendments and periodically gathered into a new edition of thestandard. RTCM 10403x for dgNSS services is proving useful in supporting highly accurate differentialand kinematic positioning as well as a wide range of navigation applications worldwideNote that Version 3 messages are not compatible with Version 2. x. Since many receivers have beendesigned and programmed for use with Version 2. x messages, rtCm is maintaining both standards0402 3 and 10403, 3 as" standardsVersion 3.0The initial edition consisted primarily of messages designed to support real-time kinematic (RTK)operations. The reason for this emphasis is that rtk operation involves broadcasting a lot of informationand thus benefits the most from an efficient data format. Version 3.0 provided messages that supportGPS and gloNaSs rTK operations including code and carrier phase observables antenna parametersand ancillary system parametersVersion 3. 1(RTCM Standard 10403.1:The next edition, Version 3. 1 (RTCM Standard 10403. 1), incorporated GPS Network Corrections, whichenable a mobile receiver to obtain accurate rtk information valid over a large area. In addition, new GPSand GLoNaSS messages provide orbital parameters to assist in rapid acquisition a Unicode text messageis also provided for the transmission of textual data. Finally a set of messages are reserved for vendorswho want to encapsulate proprietary data in their broadcasts the gps Network Corrections enable amobile receiver to obtain accurate rtk information valid over a large area. the network rtk correctioninformation provided to a rover can be considered as interpolated corrections between the referencestations in the rtk network this interpolation is not perfect and varies with the actual conditions of theatmosphere. A residual interpolation error has to be expected. With sufficient redundancy in the RtKnetwork, the network server process can provide an estimate for residual interpolation errors. Suchquality estimates may be used by the rover to optimize the performance of rtk solutions The values maybe considered by the rover as a priori estimates only with sufficient tracking data available the rovermight be able to judge residual geometric and ionospheric errors itselfVersion 3. 1. Amendment 1:Amendments 1 was an extensive addition that adds rtcm messages containing transformation data andinformation about Coordinate reference Systems. For rtCm data supporting a rtk service, coordinatesare measured within the itrf or a regional realization surve yors and other users of rtk services mustnormally present their results in the coordinates of local datums. Therefore, coordinate transformationsare necessary. by having RTCM messages that contain transformation data and information about theCoordinate reference systems the users of the rtk service can obtain their results in the desired datumwithout any manual operations. the rtk service providers can then ensure that current information forthe computation of the transformations is always used. the convenience of this method will promote theacceptance of rtK servicesVersion 3. 1. amendment 2:Amendment 2 added residual error messages to support the use of Non-Physical or Computed referenceStations in a network rtk environmentVersion 3. 1. amendment 3:Amendment 3 addressed differences in the way gnss receiver manufacturers have implemented carrierphase encoding of some Version 3 messages so that carrier phase observations are in phase for all carrierphases of a specific frequency i e. they correct for quarter cycle phase shifts. others retain the quartercycle offset between the carrier phase observations in the data. this amendment documents the waydifferent manufacturers have handled the phase shift issue and prescribes a uniform approach for futureproducts.∨ersiⅰon3.1, Amendment4:Amendment 4 added sections 3.5.13 on glONASS Network rtK Correction Messages and 3.5. 14 on FKPNetwork Rtk Correction Messages Related revisions were also made elsewhere in the document.Version 3. 1. amendment 5Amendment 5 added section 3. 5. 12 on State Space Representation related revisions are also madeelsewhere in the document, along with some editorial correctionsVersion 3. 2(RTCM Standard 10403.2)Version 3.2 consolidates Version 3. 1 and all five amendments into a new edition, and it adds MultipleSignal Messages (MSM)as well. the Multiple Signal Message (MSm)format generates receiverobservables in the same way for all included satellite systems. the messages include compact and fullmessages for Pseudorange, PhaseRange, Carrier to Noise Ratio (standard and high resolution), andPhaseRangeratea table near the beginning of the standard lists which messages were included in each separate editionand amendment, so it should not be necessary for users to refer to older versions. Multiple signalMessages are a generic format that will be followed for all GNSs systems. version 3 originally consisted ofmessages for GPS and GLONASS, each in their own format Now with the imminent addition of signals forBeiDou, Galileo, and QZSS, as well as new signals provided by modernized GPS and GloNASS satellitesthe need for a consistent generic format became evident. service providers and users are urged to migrateto the MsM messages to make it easier to accommodate new gNss services(See The RTCM Multiple Signal Messages: A New Step in GNSS Data Standardization")Another newmessage is the gloNaSS Bias Information message. This message provides information which is intendedto compensate for the first-order inter-frequency phase range biases introduced by the reference receivercode- phase biasVersion 3.2, Amendment 1:Added Galileo F/NAv Satellite Ephemeris Data(msg. 1045 )and Bds MSM(msgs. 1121-1127)Version 3.2 amendment 2Added qzss ephemeris(msg. 1044 )and QZss MSm (msgs. 1111-1117Version 3. 3(RTCM Standard 10403.3)This new edition adds Satellite-Based Augmentation System Multiple Signal Messages to previouslydopted messages for GPS, GLONASS, Galileo, and QzssA new ephemeris message has been added for BeiDou(BDS)and a new I/NAV ephemeris message hasbeen added for Galileo. The new edition also reserves 100 messages be used exclusively by sc104 fornew message developmentFinally, the new edition makes consolidates previous amendments and makes numerous editorialImprovementsNavstar GPS Service, Version 2. x. Service providers and vendors represented on the scco000c30z1O2co00c30Contentsco00c30
- 2020-06-27下载
- 积分：1
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小波变换的图像去噪的matlab程序的源代码
小波变换的图像去噪的matlab程序的源代码
- 2020-12-02下载
- 积分：1
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《 GPS应用程序设计》_李洪涛（pdf+源代码）
该书已经绝版，是一本经典著作。压缩文件包含电子书和书中的源代码。
- 2020-11-28下载
- 积分：1
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模糊控制算法程序（MATLAB编写)
用MATLAB编写的离散模糊控制程序，结合本程序，我相信能能更快更好的理解模糊控制算法。算法在MATLAB Version: 7.14.0.739 (R2012a)运行无误。function [FCU_T1,FCU_T2,FCU_T3,FCU_T4]=fuzzy_table(Me,Mec,Mu,UC)% Me 隶属度表1% Mec 隶属度表2% Mu 隶属度表3% UC 模糊规则% FCU_T1 重心加权法，输出精确值% FCU_T2 重心加权法，输出离散值% FCU_T3 重心加权法（对隶属度平方），输出离散值% FCU_T4 最大隶属度法function [
- 2020-12-01下载
- 积分：1
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光纤通信中数字信号处理
论文，高速光纤通信与数字信号处理。相干光接收，频偏估计，相位估计，算法。Y175785独创性(或创新性)声明本人声明所呈交的论文是本人在导师指导下进行的研究工作及取得的研究成果。尽我所知,除了文中特别加以标注和致谢中所罗列的内容以外,论文中不包含其他人已经发表或撰写过的研究成果,也不包含为获得北京邮电大学或其他教育机构的学位或证书而使用过的材料。与我一同工作的同志对本研究所做的任何贡献均已在论文中作了明确的说明并表示了谢意。申请学位论文与套料若有不实之处,本人承担一切相关责任。本人签名:-/b日期:200列2关于论文使用授权的说明学位论文作者完全了解北京邮电大学有关保留和使用学位论文的规定,即:研究生在校攻读学位期间论文工作的知认产权单位属北京邮电大学学校有权保留并向国家有关部门或机构送交论文的复印件和磁盘,允许学位论文被查阅和借阅:学校可以公布学位论文的全部或部分内容,可以允许采用影印、缩印或其它复制手段保存、汇编学位论文。本人签名:日期:20°3.2导师签名:日期:100Gb/ s PM-QPSK相干光接收机载波频偏估计和相位恢复算法的研究摘要通信网络中高速率业务的不断发展,对现有的城域网络及省际、国际骨干通信网络的传输带宽提出了更高、更迫切的要求。从目前主流的1040Gbp光传输技术向100Gbs演进成为光传输技术的发展趋势。近年来大量研究表明,相位调制及相干接收是最具前景的100Gbs光传输方式。其中,采用相干接收技术的偏振复用QPSK( PM-QPSK传输系统最被业界认可。该系统的符号速率比比特率降低4倍,因此有较高的光谱利用率,且收发机结构相对简单实现相对容易。此外,信道中的各种损伤,如色散、载波频偏、相位偏移等导致的信号损伤,都能在接收机中通过电域的数字信号处理(DSP)来灵活地补偿。对调相信号,载波与本振间的频率和相位偏移会使信号产生较大的相位失真,频偏估计和相位恢复成为相干接收机中两个重要的功能模块。本文在国家863计划课题“1000b/s相干光传输关键技术研究(2009AA01Z221)”资助下,对上述系统接收机载波频偏和相位恢复算法展开了深入研究,主要内容如下:1.研究了 PM-QPSK的系统组成结构,重点研究了接收机DSP各组成模块的功能,并设计实现了相干接收机后端Maab仿真平台。2.详细分析了载波频偏估计算法,设计了算法并行处理实施方案以解决现有硬件处理速率不足够高的问题,并仿真验证了方案的可行性。设计了四次方频偏估计算法的并行结构;提出了基于误码性能反馈的 BA-PADE( BER-Aided pre-decision- based Angle DifferentialEstimator)算法,解决了传统PADE要求初始频偏设置与真实频偏接近的问题;提出了基于PADE的并行处理算法一一分组PADE( Grouped-PADE)。所设计方案均通过系统仿真验证了可行性。3.详细分析了载波相位恢复算法,为采用现有FPGA或DSP实现l00Gb/级信号处理,设计了载波相位恢复并行处理方案并仿真验证了方案的可行性。设计了基于Ⅴ iterbj- Viterbi的优化算法及其并行处理结构,将其同频偏估计并行算法联合进行了二进制定点仿真分析,仿真结果表明并行处理方案可显著降低硬件处理速率要求。关键词光传输相干接收频偏相位恢复THE RESEARCH OF FREQUENCY OFFSET ESTIMATIONAND PHASE RECOVERY ALGORITHMFOR 100Gbs OPTICAL COHERENT PM-QPSK RECEIVERABStRcTThe rapid development of high bit-rate services in communicationnetworks has instantly demanded a much higher bandwidth of coretransmission links in WAN, inter-province and international networks.The upgrade from the existing 10G/40G optical transmission to 100G hasbeen a trend. The research in recent years indicates that systems withphase modulation and coherent detection are the most promising, ofwhich PM-QPsk gets most recognitionThe PM-QPsK lowers the symbol rate as 1/4 of bit rate whichprovide high spectrum efficiency, and the transceiver structure ofPM-QPSK is simpler and so is easier to realize. Besides, with digitalalgorithms, the electrical Digital Signal Processing(DSP)in thee receivercan flexibly compensate the channel distortion caused by dispersion,carrier frequency offset and phase distortion. Since the phase distortioncaused by frequency and phase offset between lo and carrier is one ofthe main distortions in PM-QPSK, frequency offset compensation andphase recovery act as two of the core modules.With the support of National 863 Project"Research of the KeyTechnologies of 100Gb/s Optical Coherent Transmission Systems?", thisthesis mainly focuses on the research of the digital algorithms of carrierfrequency offset compensation and carrier phase recovery in the receiverof PM-QPSK system and the main contents are as follows1. Investigation of PM-QPSK structure, mainly on the receiver DSPstructure, including function of the several modules in this partDesigning and implementation of the Matlab simulation platform for theback-end of PM-QpsK receiver.2. Analysis on the carrier frequency offset estimation algorithmsdesigning of the parallel structure of the algorithms in order to break therestriction of hardware speed, with feasibility testified by simulationDesigning of the parallel structure of the 4 power method Designing ofBA-PADE (BER-Aided Pre-decision-based Angle Differential Estimator)based on BER feed-back to break the exact initialization restriction oftraditional PADE. Designing of a parallel operation scheme based onPADE, namely Grouped-PADE. Feasibility of both the forementionedscheme testified by simulation.3. Analysis on the carrier phase recovery algorithms, designing ofthe parallel operation scheme in order to realize phase recovery in100Gb/s PM-QPSK with current FPGA or DSP, with feasibility testifiedby simulation. Designing of the optimized and the parallel structure ofViterbi- Viterbi (V-V)method, and binary fixed-point simulation ofparallel v-v together with frequency offset algorithm, the result provedthat the scheme could observably lower the request to the hardwareoperation speedKEYWORDS optical transmission coherent detectionfrequency offset phase recovery
- 2020-12-05下载
- 积分：1
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电机学-许实章 介绍的很详细
是学习电机学，以及在工程中应用查阅得很好的一本文献资料。
- 2020-12-04下载
- 积分：1
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STM32F103C8T6
【实例简介】内含STM32F103C8T6电路原理图及PCB图，方便开发使用
- 2021-11-08 00:31:46下载
- 积分：1
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weka全部算法源代码
著名数据挖掘软件weka的全部算法源代码；关于weka源代码的学习可以进http://quweiprotoss.blog.163.com/blog看看，对初学者，进阶者都有不少收获！
- 2020-06-25下载
- 积分：1
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张正友相机标定棋盘格pdf文件
张正友相机标定棋盘格pdf文件 直接下载 打印可用 PDF文件
- 2021-05-06下载
- 积分：1
