公开(公告)号：US07120198B1

公开(公告)日：2006-10-10

申请号：US09318560

申请日：1999-05-26

申请人： Philip A. Dafesh ,  Tien M. Nguyen

发明人： Philip A. Dafesh ,  Tien M. Nguyen

IPC分类号： H04L5/12 ,  H04L23/02

CPC分类号： H04L27/3461 ,  G01S19/02 ,  H04B1/707 ,  H04L27/2067 ,  H04L27/361

摘要： A coherent adaptive subcarrier modulation system applies subcarrier modulation to quadrature modulated signals with constant envelope modulation suitable for efficient sinewave and squarewave subcarrier modulations. The quadrature subcarrier enables the addition of new signals to the in-phase and quadrature phase signals with spectral isolation in the Global Position System while maintaining a constant envelop amplitude.

摘要翻译： 相干自适应子载波调制系统对具有恒定包络调制的正交调制信号应用子载波调制，适用于有效的正弦波和方波子载波调制。 正交子载波使得能够在保持恒定的包络幅度的同时在全局位置系统中具有光谱隔离的同相和正交相位信号的新信号。

公开(公告)号：US07469026B2

公开(公告)日：2008-12-23

申请号：US10092758

申请日：2002-03-07

申请人： Tien M. Nguyen ,  James Yoh ,  Ashok Mathur ,  Gary W. Goo

发明人： Tien M. Nguyen ,  James Yoh ,  Ashok Mathur ,  Gary W. Goo

IPC分类号： H04L25/38 ,  H03D3/22

CPC分类号： H04L7/0331

摘要： A timing recovery loop includes a random walk filter counter for counting early, nominal and late arrivals of data transitions pulses of an input baseband signal waveform encoding a digital bit stream, and provides magnitude counts that are compared to a threshold value that when exceeded by the magnitude counts results in a delay adjustment of the generated adjusted timing pulses then remaining synchronized with the actual bit timing for maintaining bit timing lock. The adjusted timing pulses can then be used by a data detector for reliable data detection and reconstruction of the digital bit stream. The threshold value can be adaptively adjusted for reducing drop lock rates in the presence of changing channel environments.

摘要翻译： 定时恢复回路包括随机游走滤波器计数器，用于对编码数字比特流的输入基带信号波形的数据转换脉冲的早期，标称和迟到到达进行计数，并提供与阈值相比较的幅度计数， 幅度计数导致所产生的调整定时脉冲的延迟调整，然后与用于维持位定时锁定的实际位定时保持同步。 所调整的定时脉冲然后可被数据检测器用于数字位流的可靠数据检测和重建。 可以自适应地调整阈值，以便在存在不断变化的信道环境的情况下减少丢弃锁定速率。

公开(公告)号：US06804493B2

公开(公告)日：2004-10-12

申请号：US10115759

申请日：2002-04-03

申请人： Tien M. Nguyen ,  Jack K. Holmes

发明人： Tien M. Nguyen ,  Jack K. Holmes

IPC分类号： H04B7185

CPC分类号： H04B7/18573

摘要： A command and telemetry communication system includes a downlink subsystem having a spacecraft downlink transmitter communicating a quadrature component carrying a pilot code for coarse acquisition and an inphase component carrying a Walsh-Hadamard code and a PN code for fine acquisition using spread spectrum signaling and amplitude modulation for code division multiplexing to downlink receivers respectively disposed in a plurality of mobile surface landers, and includes an uplink subsystem having a spacecraft uplink receiver and lander uplink transmitters communicating code division multiple access telemetry data using spread spectrum signaling and phase modulation. The communication system enables command and telemetry control of a plurality of mobile surface landers.

摘要翻译： 命令和遥测通信系统包括具有航天器下行链路发射机的下行链路子系统，所述下行链路发射机传送携带用于粗略采集的导频码的正交分量和携带沃尔什 - 哈达马码的同相分量，以及使用扩频信令和幅度调制的精细采集的PN码 用于对分别设置在多个移动表面着陆器中的下行链路接收机进行码分复用，并且包括具有航天器上行链路接收机的上行链路子系统和使用扩频信令和相位调制来通信码分多址接入遥测数据的着陆器上行链路发射机。 通信系统使得能够对多个移动表面着陆器进行命令和遥测控制。

公开(公告)号：US06429740B1

公开(公告)日：2002-08-06

申请号：US09533571

申请日：2000-03-23

申请人： Tien M. Nguyen ,  James Yoh ,  Andrew S. Parker ,  Diana M. Johnson

发明人： Tien M. Nguyen ,  James Yoh ,  Andrew S. Parker ,  Diana M. Johnson

IPC分类号： H03F126

CPC分类号： H03F1/3241

摘要： A predistortion method uses an extended Saleh model for linearizing the output of nonlinear high power amplifiers having inherent amplitude modulation to amplitude modulation distortion, and inherent amplitude modulation to phase modulation distortion, during conversions of an input signal to an output signal. A complex baseband linearizer provides predistortion at baseband for reducing spectral regrowth and improves bit error performance. The predistortion effects are matched to the amplifier distortions to cancel out the distortions to provide linearized conversions. The extended Saleh model provides a general solution using selected coefficients matched to distortion effects of a particular amplifier.

摘要翻译： 预失真方法使用扩展的Saleh模型，用于在将输入信号转换为输出信号的过程中将具有固有幅度调制的非线性高功率放大器的输出线性化为幅度调制失真，以及固有幅度调制到相位调制失真。 复基带线性化电路在基带处提供预失真以减少频谱再生长并改善误码性能。 预失真效应与放大器失真匹配，以消除失真以提供线性化转换。 扩展的Saleh模型提供了使用与特定放大器的失真效应匹配的所选系数的一般解决方案。

公开(公告)号：US06411661B1

公开(公告)日：2002-06-25

申请号：US09307231

申请日：1999-05-07

申请人： Tien M. Nguyen ,  Jack K. Holmes ,  Srini H. Raghavan

发明人： Tien M. Nguyen ,  Jack K. Holmes ,  Srini H. Raghavan

IPC分类号： H03D300

CPC分类号： H04L27/2275 ,  H04L7/0004 ,  H04L7/0331 ,  H04L7/0334 ,  H04L2027/0028 ,  H04L2027/0046

摘要： A GMSK timing recovery loop in a receiver of a Gaussian Minimum Shift Keying (GMSK) link with a low channel Bit Signal-to-Noise Ratio (BSNR) and a small bandwidth-bit period BT product in a high bandwidth efficiency channel, includes a hard limiter for converting at baseband a GMSK demodulated received signal into a hard clocking signal clocking a conventional digital tracking transition loop generating the bit timing signal in closed loop control for stable time tracking performance for coherent demodulation of GMSK signals. The hard limiter provides the hard clocking signal at baseband having transitions at multiple bit periods adjusted by the bit timing error signal from the digital tracking transition loop for providing reduced jitter of the bit timing signal for accurate timing recovery and detection of communicated data.

摘要翻译： 具有低通道位信噪比（BSNR）和高带宽效率信道中的小带宽位周期BT乘积的高斯最小移位键控（GMSK）链路的接收机中的GMSK定时恢复环路包括 硬限幅器，用于在基带处将GMSK解调的接收信号转换为硬时钟信号，该硬时钟信号使传统的数字跟踪转换回路产生闭环控制中的位定时信号，以稳定的时间跟踪性能用于GMSK信号的相干解调。 硬限幅器在基带处提供硬时钟信号，其具有通过来自数字跟踪转换环路的位定时误差信号调整的多个位周期的转变，以提供用于精确定时恢复和传送数据检测的减少的抖动。

公开(公告)号：US06307435B1

公开(公告)日：2001-10-23

申请号：US09534105

申请日：2000-03-23

申请人： Tien M. Nguyen ,  James Yoh ,  Andrew S. Parker ,  Diana M. Johnson

发明人： Tien M. Nguyen ,  James Yoh ,  Andrew S. Parker ,  Diana M. Johnson

IPC分类号： H03F126

CPC分类号： H03F1/3241

摘要： A predistortion method use a modified linear-log model for linearizing the output of nonlinear high power amplifiers having inherent amplitude modulation to amplitude modulation distortion, and inherent amplitude modulation to phase modulation distortion, during conversions of an input signal to an output signal. A complex baseband linearizer provides predistortion at baseband for reducing spectral regrowth and improves bit error performance. The predistortion effects are matched to the amplifier distortions to cancel out the distortions to provide linearized conversions. The modified linear-log model is used to reduce the clipping effects through the peak operating point for a specified output power loss with minimum distortion.

摘要翻译： 预失真方法使用修正的线性对数模型，用于在将输入信号转换为输出信号的过程中，将具有固有幅度调制的非线性高功率放大器的输出线性化为幅度调制失真，以及将固有的幅度调制转换为相位调制失真。 复基带线性化电路在基带处提供预失真以减少频谱再生长并改善误码性能。 预失真效应与放大器失真匹配，以消除失真以提供线性化转换。 经修改的线性对数模型用于通过峰值工作点减小对具有最小失真的指定输出功率损耗的削波效应。

公开(公告)号：US07145972B2

公开(公告)日：2006-12-05

申请号：US09982383

申请日：2001-10-18

申请人： Rajendra Kumar ,  Tien M. Nguyen

发明人： Rajendra Kumar ,  Tien M. Nguyen

IPC分类号： H04B1/10

CPC分类号： H04L5/06

摘要： A polyphase channelizer converts an intermediate frequency wideband signal into a complex signal that is sampled by parallel analog-to-digital converters having a bank of samplers respectively clocked by staggered clocking signals for respective converters for feeding I and Q quadrature samples to a polyphase filter bank of finite impulse response filters driving a fast Fourier transform processor for providing channelized digital signal outputs. The parallel analog-to-digital converters can operate at lower speeds but are parallel connected for effectively operating at required higher speeds. The channelizer channelizes the wideband signal using a polyphase clock for enabling high speed sampling and converting through low speed parallel analog to digital converters.

公开(公告)号：US6148040A

公开(公告)日：2000-11-14

申请号：US431343

申请日：1999-10-29

申请人： Tien M. Nguyen ,  John M. Charroux

发明人： Tien M. Nguyen ,  John M. Charroux

IPC分类号： H04L25/06 ,  H04L25/49 ,  H04L27/00 ,  H04L27/20 ,  H04L27/227 ,  H04L27/14

CPC分类号： H04L27/2017 ,  H04L25/061 ,  H04L25/4904 ,  H04L27/2273 ,  H04L2027/003 ,  H04L2027/0061 ,  H04L2027/0067

摘要： An improved Gaussian minimum shift keying (GMSK) carrier tracking loop operating at baseband takes advantage of the orthogonality of precoded data GMSK signals and Laurent filtering to provide a carrier phase error signal generated at baseband for carrier phase derotation of the received GMSK signal. The carrier tracking loop also provides demodulated data estimates with performance equal to that of a GMSK serial demodulator. The tracking loop uses data directed feedback to improve noise rejection, but still has fast acquisition by operating at baseband.

摘要翻译： 在基带上操作的改进的高斯最小移动键控（GMSK）载波跟踪环路利用预编码数据GMSK信号和洛朗滤波的正交性，以提供在基带处生成的载波相位误差信号，用于载波相位旋转所接收的GMSK信号。 载波跟踪环路还提供具有与GMSK串行解调器相同性能的解调数据估计。 跟踪循环使用数据定向反馈来改善噪声抑制，但是仍然通过在基带操作来快速获取。

公开(公告)号：US08362945B2

公开(公告)日：2013-01-29

申请号：US12897660

申请日：2010-10-04

申请人： Tien M. Nguyen ,  John J. Wootan

发明人： Tien M. Nguyen ,  John J. Wootan

IPC分类号： G01S13/00

CPC分类号： G01S13/887

摘要： Systems and methods for detecting and tracking a gun using millimeter waves are provided. In one embodiment, the invention relates to a method for detecting and tracking a gun using radio frequency waves at millimeter wavelengths, the method including storing empirical data, for up to N types of guns, including information indicative of a resonant frequency of a barrel of each of the N guns, generating pulse energy including at least one sequence of pulses at millimeter wave frequencies for each of the N guns, transmitting the pulse energy, receiving reflected pulse energy, filtering the reflected pulse energy to a preselected bandwidth for each of the N guns, determining a first maximum value of the filtered reflected pulse energy in each of the preselected bandwidths that exceeds a preselected threshold, determining a second maximum value among the first maximum values, and correlating a frequency of the second maximum value with the stored resonant frequencies of the N guns to identify a gun.

摘要翻译： 提供了使用毫米波检测和跟踪枪的系统和方法。 在一个实施例中，本发明涉及一种利用毫米波长的射频波检测和跟踪枪的方法，所述方法包括存储经验数据，用于多达N种类型的枪，包括指示桶的共振频率的信息 每个N个枪，产生脉冲能量，其包括用于N个枪中的每一个的毫米波频率的至少一个脉冲序列，发射脉冲能量，接收反射的脉冲能量，将反射的脉冲能量滤波成每个的预选带宽 N个枪，确定超过预选阈值的每个预选带宽中经滤波的反射脉冲能量的第一最大值，确定第一最大值中的第二最大值，并将第二最大值的频率与存储的谐振 N枪的频率来识别枪。

公开(公告)号：US20120256779A1

公开(公告)日：2012-10-11

申请号：US12897660

申请日：2010-10-04

申请人： Tien M. Nguyen ,  John J. Wootan

发明人： Tien M. Nguyen ,  John J. Wootan

IPC分类号： G01S13/02

CPC分类号： G01S13/887

摘要： Systems and methods for detecting and tracking a gun using millimeter waves are provided. In one embodiment, the invention relates to a method for detecting and tracking a gun using radio frequency waves at millimeter wavelengths, the method including storing empirical data, for up to N types of guns, including information indicative of a resonant frequency of a barrel of each of the N guns, generating pulse energy including at least one sequence of pulses at millimeter wave frequencies for each of the N guns, transmitting the pulse energy, receiving reflected pulse energy, filtering the reflected pulse energy to a preselected bandwidth for each of the N guns, determining a first maximum value of the filtered reflected pulse energy in each of the preselected bandwidths that exceeds a preselected threshold, determining a second maximum value among the first maximum values, and correlating a frequency of the second maximum value with the stored resonant frequencies of the N guns to identify a gun.

摘要翻译： 提供了使用毫米波检测和跟踪枪的系统和方法。 在一个实施例中，本发明涉及一种利用毫米波长的射频波检测和跟踪枪的方法，所述方法包括存储经验数据，用于多达N种类型的枪，包括指示桶的共振频率的信息 每个N个枪，产生脉冲能量，其包括用于N个枪中的每一个的毫米波频率的至少一个脉冲序列，发射脉冲能量，接收反射的脉冲能量，将反射的脉冲能量滤波成每个的预选带宽 N个枪，确定超过预选阈值的每个预选带宽中经滤波的反射脉冲能量的第一最大值，确定第一最大值中的第二最大值，并将第二最大值的频率与存储的谐振 N枪的频率来识别枪。