公开(公告)号：US06487251B1

公开(公告)日：2002-11-26

申请号：US09386053

申请日：1999-08-30

申请人： Yezdi Antia ,  Zhen-Liang Shi ,  A. Roger Hammons, Jr. ,  Olga Ritterbush

发明人： Yezdi Antia ,  Zhen-Liang Shi ,  A. Roger Hammons, Jr. ,  Olga Ritterbush

IPC分类号： H04L2701

CPC分类号： H04L1/0068 ,  H04L1/0041 ,  H04L1/007 ,  H04L1/08

摘要： A system and method for establishing an integrated forward error correction (FEC) scheme to perform multi-rate encoding on different priority data bits of a channel access message transmitted on a random access channel between devices of a communications network, such as between an access terminal and a base station of a satellite-based communications network. The channel access message includes a first data group representing first information and a second data group representing second information, which is transmitted between an access terminal and a base station in a satellite-based communications network. The system and method encodes the second data group at an encoding rate to provide a second encoded data group, and encodes the first data group at the same encoding rate to provide a first encoded data group. The encoding of the first and second data groups is performed by a single encoder, such as a rate ¼ convolutional encoder. The second encoded data group is transmitted from the access terminal to the base over a random access channel. The second encoded data group further can be punctured during transmission to in effect decrease its coding rate, for example, to rate ½ coding. The first encoded data group is transmitted from the access terminal to the base station, and is then retransmitted from the access terminal to the base station to in effect increase the rate of coding of the first encoded data group to, for example, ⅛ coding. At the base station, a combiner/demodulator combines the transmitted and retransmitted first encoded data group, and the combined first encoded data groups and the second encoded data group are then decoded by a decoder.

摘要翻译： 一种用于建立综合前向纠错（FEC）方案的系统和方法，用于对通信网络的设备之间在诸如接入终端之间的随机接入信道上发送的信道接入消息的不同优先级数据比特执行多速率编码 以及基于卫星的通信网络的基站。 信道接入消息包括表示第一信息的第一数据组和表示在基于卫星的通信网络中的接入终端和基站之间传输的第二信息的第二数据组。 该系统和方法以编码速率对第二数据组进行编码以提供第二编码数据组，并以相同的编码速率对第一数据组进行编码以提供第一编码数据组。 第一和第二数据组的编码由单个编码器执行，例如速率¼卷积编码器。 第二编码数据组通过随机接入信道从接入终端发送到基站。 第二编码数据组在传输期间还可以被打孔，从而实际上降低了其编码率，例如，对1/2编码进行速率估计。 第一编码数据组从接入终端发送到基站，然后从接入终端重传到基站，实际上将第一编码数据组的编码速率提高到例如1/8 编码。 在基站，组合器/解调器组合发送和重传的第一编码数据组，然后由解码器解码组合的第一编码数据组和第二编码数据组。

公开(公告)号：US06349120B1

公开(公告)日：2002-02-19

申请号：US09205592

申请日：1998-12-04

申请人： Zhen-Liang Shi ,  Yezdi Antia ,  A. Roger Hammons, Jr.

发明人： Zhen-Liang Shi ,  Yezdi Antia ,  A. Roger Hammons, Jr.

IPC分类号： H04L2706

CPC分类号： H04L25/03828 ,  H04L27/2655

摘要： A method for improving spectral sampling using Discrete Fourier Transforms in a processor to detect a continuous wave (CW) signal in a burst having large initial uncertainties comprises the steps of dividing the burst into smaller sub-bursts; performing a Discrete Fourier Transform on each sub-burst; and non-coherently combining each sub-burst. A further variation includes selecting an optimal number L of sub-bursts based upon system performance, and desired detection performance at a minimum operating signal to noise ratio.

摘要翻译： 一种在处理器中使用离散傅立叶变换改进频谱采样的方法，用于检测具有大的初始不确定性的脉冲串中的连续波（CW）信号，包括以下步骤：将脉冲串划分成更小的子脉冲串; 对每个子突发执行离散傅里叶变换; 并且不相干地组合每个子突发。 进一步的变化包括基于系统性能选择最佳数量L的子脉冲串，并且以最小的操作信噪比选择期望的检测性能。

公开(公告)号：US06373858B1

公开(公告)日：2002-04-16

申请号：US09110035

申请日：1998-07-02

申请人： Mohammad Soleimani ,  A. Roger Hammons, Jr. ,  Zheng-Liang Shi ,  Yash Vasavada ,  Moe Rahnema ,  Yezdi Antia

发明人： Mohammad Soleimani ,  A. Roger Hammons, Jr. ,  Zheng-Liang Shi ,  Yash Vasavada ,  Moe Rahnema ,  Yezdi Antia

IPC分类号： H04J300

CPC分类号： H04L7/042 ,  H04L2007/047

摘要： A message format and associated method for estimating the frequency and timing offset of a reference burst of a random access channel in a time-division multiple access communications system. A signal structure in which the continuous wave segment is split into two parts separated by some portion of the content of the random access channel burst is used to provide more precise frequency estimation. Iteration of separate frequency and timing estimation procedures is used to refine both estimates, as the individual estimation processes are more accurate when there is less error in the other parameter. Multiple hypothesis testing is used, in which more than one initial frequency estimate is carried through the iteration process, with thresholding to identify the best frequency offset. Reliable rejection of false ambiguities is achieved because the degradation in timing estimation, due to large frequency offsets, can be detected with thresholding.

摘要翻译： 一种用于估计时分多址通信系统中的随机接入信道的参考突发的频率和定时偏移的消息格式和相关联的方法。 使用连续波段被分割成由随机接入信道突发的内容的一部分分开的两部分的信号结构来提供更精确的频率估计。 单独的频率和时间估计过程的迭代用于改进两个估计，因为当另一个参数中的误差较小时，各个估计过程更准确。 使用多重假设检验，其中通过迭代过程承载多于一个初始频率估计，并通过阈值来识别最佳频率偏移。 由于可以通过阈值来检测由于大的频率偏移导致的定时估计的劣化，所以可以得到可靠的误差模糊的拒绝。

公开(公告)号：US07012937B2

公开(公告)日：2006-03-14

申请号：US09768728

申请日：2001-01-24

申请人： Bassel Beidas ,  Olga Ritterbush ,  Stanley Kay ,  Yezdi Antia ,  Bala Subramaniam

发明人： Bassel Beidas ,  Olga Ritterbush ,  Stanley Kay ,  Yezdi Antia ,  Bala Subramaniam

IPC分类号： H04J3/06

CPC分类号： H04J3/0611 ,  H04B7/2125 ,  H04J3/0605 ,  H04L7/0004 ,  H04L7/043 ,  H04L7/10

摘要： A method and system for tracking a time division multiplexed synchronization signal in a satellite communication system is provided. The signal is provided as a series of frames with beacon signals time division multiplexed into at least one time slot of each frame. The beacon signal in each frame comprises a unique word sequence, which is the same in each frame, and a portion of a PN sequence. The entire PN sequence is distributed into a plurality of frames forming a superframe. Frequency variations of the incoming signal are tracked at the satellite terminal by correlating the PN sequence of the incoming signal against early and late locally generated versions of the PN sequence in a discriminate circuit. The output of the discriminate is provided to a delay locked loop circuit of at least third order. The output of the loop is used to adjust the frequency of the VCO, which clocks the A/D converter operating on the incoming signal. The product of the PN sequence of the incoming signal and an on-time locally generated version of the PN sequence is provided to an FFT circuit. The satellite terminal determines if it is locked onto the incoming signal based on the output of the FFT. If the satellite terminal is not locked, the terminal returns to an acquisition mode.

公开(公告)号：US06182251B2

公开(公告)日：2001-01-30

申请号：US09198774

申请日：1998-11-24

申请人： Moe Rahnema ,  Zhen-Liang Shi ,  Ludong Wang ,  Yezdi Antia ,  Mohammad Soleimani

发明人： Moe Rahnema ,  Zhen-Liang Shi ,  Ludong Wang ,  Yezdi Antia ,  Mohammad Soleimani

IPC分类号： G06F1100

CPC分类号： H04L25/023

摘要： A method of channel estimation in a wireless communication system has steps of receiving a data burst comprising a plurality of portions of known data, and remaining data that is unknown; comparing reference data to each of the plurality of portions of known data and determining error for each of the portions of known data; averaging the determined error for predetermined ones of the portions of known data; and estimating error for at least a portion of the remaining data as a function of the determined error having been averaged.

摘要翻译： 在无线通信系统中的信道估计方法具有接收包括已知数据的多个部分的数据脉冲串和未知的剩余数据的步骤; 将参考数据与已知数据的多个部分中的每一个进行比较，并确定已知数据的每个部分的误差; 对已知数据的预定部分的所确定的误差进行平均; 以及根据所确定的误差的函数估计剩余数据的至少一部分的误差。

公开(公告)号：US07042854B2

公开(公告)日：2006-05-09

申请号：US09768726

申请日：2001-01-24

申请人： Bassel Beidas ,  Olga Ritterbush ,  Stanley Kay ,  Yezdi Antia ,  Bala Subramaniam

发明人： Bassel Beidas ,  Olga Ritterbush ,  Stanley Kay ,  Yezdi Antia ,  Bala Subramaniam

IPC分类号： H04B7/212

CPC分类号： H04J3/0611 ,  H04B7/2125 ,  H04L7/0004

摘要： A method and system for acquiring a time division multiplexed synchronization signal in a satellite communication system is provided. The signal is provided as a series of frames with beacon signals time division multiplexed into at least one time slot of each frame. The beacon signal in each frame comprises a unique word sequence, which is the same in each frame, and a portion of a PN sequence. The entire PN sequence is distributed into a plurality of frames forming a superframe. Initially, the power level of the incoming signal is determined by locating the maximum power received in half time slot intervals. Next a series of frames are correlated against the expected unique word, each at one of a plurality of possible frequencies. The frequency generating the maximum correlation with the unique word is selected. The frequency is fine tuned by comparing the actual arrival time of the unique word in each frame with the estimated arrival time based on the current frequency, and adjusting the frequency accordingly. Also, the start of the superframe is located by correlating the PN sequence portion of each beacon signal against a known PN sequence until a match is found. Once the frequency offset is reduced below a threshold value, and the start of the PN sequence of the incoming signal is located, acquisition is completed.

公开(公告)号：US10819419B2

公开(公告)日：2020-10-27

申请号：US16518363

申请日：2019-07-22

申请人： Murali Regunathan ,  Yezdi Antia ,  Neal David Becker ,  Stanley Kay ,  Uday R. Bhaskar

发明人： Murali Regunathan ,  Yezdi Antia ,  Neal David Becker ,  Stanley Kay ,  Uday R. Bhaskar

IPC分类号： H04B7/185 ,  H04B7/204 ,  H04L7/00 ,  H04B7/06 ,  H04W72/04 ,  H04L27/26 ,  H04W28/18

摘要： A system and method for timing synchronization of satellite switching instants with gateway switching instants is described. The method includes: generating satellite switching instants according to a Beam Hopping Time Plan (BHTP); generating gateway switching instants according to the BHTP; transmitting a channel addressed to a plurality of beams hopped according to the BHTP based on the gateway switching instants, wherein each of the plurality of beams includes a signal including timing markers and a guard period at an end of the signal for the respective beam; receiving a synchronization information, without a loopback beam, for one of the plurality of beams; determining an adjustment period and an adjusted symbol rate for the generating of the gateway switching instants, based on the synchronization information, for a transmission of the channel such that at least a portion of the guard period in a respective signal for a respective beam aligns with one of the satellite switching instants; and adjusting a timing and a symbol rate of the transmission according to the adjustment period and the adjusted symbol rate, respectively.

公开(公告)号：US08711759B2

公开(公告)日：2014-04-29

申请号：US13538119

申请日：2012-06-29

申请人： Udaya R. Bhaskar ,  Yezdi Antia ,  Satyajit Roy

发明人： Udaya R. Bhaskar ,  Yezdi Antia ,  Satyajit Roy

IPC分类号： H04B7/185

CPC分类号： H04B7/2048 ,  H04B7/18513 ,  H04B7/2125 ,  H04W56/001

摘要： Aspects of the invention provide a system and method to allow inroute frame timing synchronization without the aid of hub signal loopback or satellite ephemeris data. Furthermore, it allows tracking and compensating of the satellite motion to allow multiple remotes to use TDMA on the inroute frequencies, while minimizing the aperture. Two main techniques proposed are CLT and polling based approaches, which are used in combination for an optimum solution. In CLT based approach, hub transmits remote specific timing correction feedback messages on the outroute on as needed basis. In polling based approach, the remotes derive their timing based on a per-beam average delay estimate broadcast by the hub and a measured local delay specific to each outroute stream from a remote. An aspect of the invention uses triangulation method to determine satellite position. Furthermore, an aspect of the invention uses hub burst arrival method instead of polling approach.

摘要翻译： 本发明的方面提供了一种系统和方法，其允许在无需集线器信号环回或卫星星历数据的帮助下进行帧定时同步。 此外，它允许跟踪和补偿卫星运动，以允许多个遥控器在最小化孔径的同时使用TDMA在路由频率上。 提出的两个主要技术是基于CLT和轮询的方法，它们被组合用于最佳解决方案。 在基于CLT的方法中，集线器根据需要在远端传输远程特定定时校正反馈消息。 在基于轮询的方法中，遥控器基于由集线器广播的每个波束的平均延迟估计和来自远程的每个外向流特定的测量的本地延迟导出其定时。 本发明的一个方面使用三角测量方法来确定卫星位置。 此外，本发明的一个方面使用集线器突发到达方法而不是轮询方法。

公开(公告)号：US20130315136A1

公开(公告)日：2013-11-28

申请号：US13538119

申请日：2012-06-29

申请人： Udaya R. Bhaskar ,  Yezdi Antia ,  Satyajit Roy

发明人： Udaya R. Bhaskar ,  Yezdi Antia ,  Satyajit Roy

IPC分类号： H04W88/04

CPC分类号： H04B7/2048 ,  H04B7/18513 ,  H04B7/2125 ,  H04W56/001

摘要： Aspects of the invention provide a system and method to allow inroute frame timing synchronization without the aid of hub signal loopback or satellite ephemeris data. Furthermore, it allows tracking and compensating of the satellite motion to allow multiple remotes to use TDMA on the inroute frequencies, while minimizing the aperture. Two main techniques proposed are CLT and polling based approaches, which are used in combination for an optimum solution. In CLT based approach, hub transmits remote specific timing correction feedback messages on the outroute on as needed basis. In polling based approach, the remotes derive their timing based on a per-beam average delay estimate broadcast by the hub and a measured local delay specific to each outroute stream from a remote. An aspect of the invention uses triangulation method to determine satellite position. Furthermore, an aspect of the invention uses hub burst arrival method instead of polling approach.

摘要翻译： 本发明的方面提供了一种系统和方法，其允许在无需集线器信号环回或卫星星历数据的帮助下进行帧定时同步。 此外，它允许跟踪和补偿卫星运动，以允许多个遥控器在最小化孔径的同时使用TDMA在路由频率上。 提出的两个主要技术是基于CLT和轮询的方法，它们被组合用于最佳解决方案。 在基于CLT的方法中，集线器根据需要在远端传输远程特定定时校正反馈消息。 在基于轮询的方法中，遥控器基于由集线器广播的每个波束的平均延迟估计和来自远程的每个外向流特定的测量的本地延迟导出其定时。 本发明的一个方面使用三角测量方法来确定卫星位置。 此外，本发明的一个方面使用集线器突发到达方法而不是轮询方法。

公开(公告)号：US07043199B2

公开(公告)日：2006-05-09

申请号：US09875607

申请日：2001-06-06

申请人： Jerry Dai ,  Stan Kay ,  Yezdi Antia ,  Zhenliang Shi ,  Anwer Khan ,  Gaguk Zakaria

发明人： Jerry Dai ,  Stan Kay ,  Yezdi Antia ,  Zhenliang Shi ,  Anwer Khan ,  Gaguk Zakaria

IPC分类号： H04B7/185

CPC分类号： H04B7/18543

摘要： An uplink power control system for terminals in a satellite communication system provides closed loop power control using feedback signals generated at a satellite. The satellite performs inter-beam routing of uplink signals from satellite terminals, and processing of uplink signals to generate terminal transmission-specific feedback information that is transmitted in downlink signals to the terminals. The satellite also generates a beacon signal. An uplink power control algorithm at each terminal uses the beacon signal and feedback data to adjust transmit power.