Laser induced breakdown spectroscopy (LIBS) apparatus for the detection of mineral and metal contamination in liquid samples

    公开(公告)号:US09958395B2

    公开(公告)日:2018-05-01

    申请号:US15424931

    申请日:2017-02-06

    摘要: This invention discloses an improved laser induced breakdown spectroscopy (LIBS) apparatus and method for the detection of mineral and metal contamination in liquid samples. The mineral and metal contaminant is first collected by filtering the liquid sample with a membrane filter. The membrane filter with the mineral and metal contaminant is then measured by a LIBS apparatus. The LIBS apparatus is based on a high repetition rate pulsed laser. The laser produces a train of laser pulses at a high repetition rate in the kHz (or even higher) range. When the laser beam hits the surface of the membrane filter, it generates several thousands of micro-plasma emissions per second. Synchronized miniature CCD array optical spectrometer modules collect the LIBS signal from these micro-plasma emissions. By adjusting the integration time of the spectrometer to cover a plurality of periods of the laser pulse train, the spectrometer integrates the LIBS signal produced by this plurality of laser pulses. Hence the intensity of the obtained LIBS spectrum can be greatly improved to increase the signal-to-noise ratio (SNR) and lower the level of detection (LOD).

    Laser induced breakdown spectroscopy (LIBS) apparatus based on high repetition rate pulsed laser

    公开(公告)号:US09797776B2

    公开(公告)日:2017-10-24

    申请号:US15166374

    申请日:2016-05-27

    摘要: This invention discloses a laser induced breakdown spectroscopy (LIBS) apparatus based on a high repetition rate pulsed laser. The laser produces a train of laser pulses at a high repetition rate in the kHz or even higher range. When the laser beam hits the sample, it generates several thousands of micro-plasma emissions per second. Synchronized miniature CCD array optical spectrometer modules collect the LIBS signal from these micro-plasma emissions. By adjusting the integration time of the spectrometer to cover a plurality of periods of the laser pulse train, the spectrometer integrates the LIBS signal produced by this plurality of laser pulses. Hence the intensity of the obtained LIBS spectrum can be greatly improved to increase the signal-to-noise ratio (SNR) and lower the limit of detection (LOD). In addition, the influence of pulse to pulse variation of the laser is minimized since the obtained LIBS spectrum is the spectrum of a plurality of micro-plasma emissions produced by a plurality of laser pulses. The high repetition rate laser also makes it possible to measure the LIBS signal at a short and a long integration time and mathematically combining the two spectra to obtain a LIBS spectrum with enhanced dynamic range.

    Laser Induced Breakdown Spectroscopy (LIBS) Apparatus for the Detection of Mineral and Metal Contamination in Liquid Samples

    公开(公告)号:US20170234800A1

    公开(公告)日:2017-08-17

    申请号:US15424931

    申请日:2017-02-06

    摘要: This invention discloses an improved laser induced breakdown spectroscopy (LIBS) apparatus and method for the detection of mineral and metal contamination in liquid samples. The mineral and metal contaminant is first collected by filtering the liquid sample with a membrane filter. The membrane filter with the mineral and metal contaminant is then measured by a LIBS apparatus. The LIBS apparatus is based on a high repetition rate pulsed laser. The laser produces a train of laser pulses at a high repetition rate in the kHz (or even higher) range. When the laser beam hits the surface of the membrane filter, it generates several thousands of micro-plasma emissions per second. Synchronized miniature CCD array optical spectrometer modules collect the LIBS signal from these micro-plasma emissions. By adjusting the integration time of the spectrometer to cover a plurality of periods of the laser pulse train, the spectrometer integrates the LIBS signal produced by this plurality of laser pulses. Hence the intensity of the obtained LIBS spectrum can be greatly improved to increase the signal-to-noise ratio (SNR) and lower the level of detection (LOD).

    QC-LDPC code decoder and corresponding decoding method
    5.
    发明授权
    QC-LDPC code decoder and corresponding decoding method 失效
    QC-LDPC码解码器及相应的解码方法

    公开(公告)号:US08321747B2

    公开(公告)日:2012-11-27

    申请号:US12669277

    申请日:2008-06-19

    IPC分类号: H03M13/00

    CPC分类号: H03M13/1137 H03M13/1105

    摘要: An efficient general QC-LDPC code decoder includes a general-purpose processor for distributing the storage storage space of the data memory block, and establishing an index for data addressing; a data memory block for storing the information used during decoding; a hardware accelerator for conducting part or all of the information processing operations including parity check, check node updating and variable node updating. A corresponding QC-LDPC code decoding method includes initializing the variable node information and performing parity check on the check matrix row block by row block; updating the check node row block by row block and updating the variable node column block by column block if any check equation is not met.

    摘要翻译: 有效的一般QC-LDPC码解码器包括用于分配数据存储块的存储空间的通用处理器,以及建立用于数据寻址的索引; 用于存储在解码期间使用的信息的数据存储块; 用于进行部分或全部信息处理操作的硬件加速器,包括奇偶校验,校验节点更新和可变节点更新。 对应的QC-LDPC码解码方法包括初始化可变节点信息,并按行块对校验矩阵行进行奇偶校验; 按行块更新校验节点行块,并且如果不满足任何检验方程,则按列块更新变量节点列。

    System and method for generating and detecting the identifier sequence of the bandwidth-limited transmitter
    6.
    发明授权
    System and method for generating and detecting the identifier sequence of the bandwidth-limited transmitter 失效
    用于生成和检测带宽限制发射机的标识符序列的系统和方法

    公开(公告)号:US08139622B2

    公开(公告)日:2012-03-20

    申请号:US12446076

    申请日:2006-11-16

    IPC分类号: H04B1/00

    摘要: A system and method for generating and detecting identifier sequence of a bandwidth-limited transmitter are disclosed, comprising an identifier sequence generating portion and a detection portion. The identifier sequence generating portion comprises: generating a frequency-domain random sequence; generating a frequency-domain orthogonal sequence; performing frequency-domain truncation; performing frequency-time transformation; and performing cycle extension. The identifier sequence receiving portion comprises: truncating the time-domain for the received signal; performing time-frequency domain transformation to obtain a frequency-domain signal; generating frequency-domain random sequence; generating a frequency-domain orthogonal sequence; correlating the frequency-domain orthogonal sequence with the frequency-domain signal de-scrambled by the frequency-domain random sequence; and detecting an output from a frequency-domain correlator by a threshold detecting device and determining the transmitter identifier sequence. The random sequence bandwidth generated by the system and the method of the present invention can be configured flexibly according to transmission bandwidth requirement, and the sequence may be arbitrarily allocated at the power of each frequency point inside the bandwidth. The present invention may be widely applied to multimedia broadcasting, terrestrial radio broadcasting, cable broadcasting and the like.

    摘要翻译: 公开了一种用于产生和检测带宽限制发射机的标识符序列的系统和方法,包括标识符序列产生部分和检测部分。 标识符序列生成部分包括:产生频域随机序列; 产生频域正交序列; 执行频域截断; 执行频率 - 时间变换; 并执行循环扩展。 标识符序列接收部分包括:截断接收信号的时域; 执行时频域变换以获得频域信号; 产生频域随机序列; 产生频域正交序列; 将频域正交序列与由频域随机序列解扰的频域信号相关; 以及通过阈值检测装置检测来自频域相关器的输出,并确定发射机标识符序列。 系统生成的随机序列带宽和本发明的方法可以根据传输带宽要求灵活配置,并且该序列可以以带宽内的每个频点的功率任意分配。 本发明可以广泛地应用于多媒体广播,地面广播,有线广播等。

    A MULTI-CARRIER DIGITAL MOBILE MULTIMEDIA BROADCAST SYSTEM AND THE DIGITAL INFORMATION TRANSMISSION METHOD THEREOF
    8.
    发明申请
    A MULTI-CARRIER DIGITAL MOBILE MULTIMEDIA BROADCAST SYSTEM AND THE DIGITAL INFORMATION TRANSMISSION METHOD THEREOF 失效
    多载波数字移动多媒体广播系统及其数字信息传输方法

    公开(公告)号:US20110051825A1

    公开(公告)日:2011-03-03

    申请号:US12446054

    申请日:2006-11-15

    IPC分类号: H04L27/28

    摘要: The present invention discloses a multi-carrier digital multimedia broadcast system and the digital information transmission method thereof. After RS encoding and byte interleaving, LDPC encoding, bit interleaving and constellation mapping to an upper layer of data streams in turn, the obtained data symbol is multiplexed with scattered pilots and continual pilots which include the system information to form an OFDM frequency domain symbol and scrambled; an OFDM time domain symbol is generated by IFFT transforming, and after inserted with the frame head to build a time slot, it is connected to form a signal frame of the physical layer; the signal frame of the physical layer is transmitted after being low-pass filtered and orthogonal upconverted. The system and method thereof provide wireless broadcast with high quality such as audio, video and multimedia data and the like for mobile, fixed and portable receivers, and can use the satellite transmission and terrestrial transmission method for transmitting. The method utilizes the LDPC OFDM scheme, and the system applies the microwave and large scale integrated circuit technologies while fulfills the needs for low cast and high performance.

    摘要翻译: 本发明公开了一种多载波数字多媒体广播系统及其数字信息传输方法。 在RS编码和字节交织之后,将LDPC编码,比特交织和星座映射依次转换成数据流的上层,所获得的数据符号与包括系统信息的散射导频和连续导频复用以形成OFDM频域符号, 炒了 通过IFFT变换生成OFDM时域符号,并且在插入帧头以构建时隙之后,连接形成物理层的信号帧; 物理层的信号帧经过低通滤波和正交上变频后传输。 其系统和方法为移动,固定和便携式接收机提供高质量的无线广播,例如音频,视频和多媒体数据等,并且可以使用卫星传输和地面传输方法进行传输。 该方法采用LDPC OFDM方案,系统应用微波和大规模集成电路技术,同时满足低速和高性能的需要。

    METHOD FOR CONSTRUCTING LDPC CODE IN THE MOBILE DIGITAL MULTIMEDIA BROADCAST SYSTEM
    9.
    发明申请
    METHOD FOR CONSTRUCTING LDPC CODE IN THE MOBILE DIGITAL MULTIMEDIA BROADCAST SYSTEM 失效
    在移动数字多媒体广播系统中构造LDPC码的方法

    公开(公告)号:US20100180175A1

    公开(公告)日:2010-07-15

    申请号:US12376644

    申请日:2006-11-13

    IPC分类号: H03M13/05 G06F11/10

    CPC分类号: H03M13/033 H03M13/1102

    摘要: A method for constructing LDPC (Low-Density Parity-Check) code in the mobile digital multimedia broadcast system is provided, wherein the Low-Density Parity-Check matrix of the LDPC code is iteratively constructed according to a code-table and expansion method, and the code-table is a part of the constructed Low-Density Parity-Check matrix. According to the constructing method of the present invention, the LDPC code having excellent performance of error correcting coding which is applicable to the mobile digital multimedia broadcast system.

    摘要翻译: 提供了一种在移动数字多媒体广播系统中构造LDPC(低密度奇偶校验)码的方法,其中根据码表和扩展方法迭代地构建LDPC码的低密度奇偶校验矩阵, 代码表是构建的低密度奇偶校验矩阵的一部分。 根据本发明的构造方法,可以应用于移动数字多媒体广播系统的具有优异的纠错编码性能的LDPC码。