公开(公告)号：US20110317722A1

公开(公告)日：2011-12-29

申请号：US13254464

申请日：2010-02-25

申请人： Vasanth Gaddam ,  Monisha Ghosh

发明人： Vasanth Gaddam ,  Monisha Ghosh

IPC分类号： H04J3/24

CPC分类号： H04L27/2607 ,  H04L1/0057 ,  H04L1/0059 ,  H04L1/0065 ,  H04L1/0072

摘要： A method (400) and apparatus for encoding a block-based communication system header. A physical (PHY) layer header and a medium access control (MAC) header of the block-based communication system header are encoded to generate parity bits, wherein the PHY layer header includes at least cyclic prefix (CP) mode bits (S410). Parity bits are appended to the PHY layer header and the MAC layer header to generate a bit vector (S420). The bit vector is divided into at least two data blocks, wherein a first data block includes at least the CP mode bits (S430). A predefined number of tail bits are appended to each data block (S440). The two data blocks are mapped into at least two symbols, wherein the first data block is mapped to a first symbol, such that the first symbol is a first header symbol being transmitted (S450).

摘要翻译： 一种用于编码基于块的通信系统报头的方法（400）和装置。 对基于块的通信系统头部的物理（PHY）层头部和介质访问控制（MAC）头部进行编码以产生奇偶校验位，其中，PHY层头部至少包括循环前缀（CP）模式比特（S410）。 奇偶校验位附加到PHY层报头和MAC层报头以产生位向量（S420）。 比特向量被划分为至少两个数据块，其中第一数据块至少包括CP模式比特（S430）。 每个数据块附加预定数量的尾比特（S440）。 两个数据块被映射到至少两个符号，其中第一数据块被映射到第一符号，使得第一符号是正被发送的第一标题符号（S450）。

公开(公告)号：US07724834B2

公开(公告)日：2010-05-25

申请号：US11571366

申请日：2005-06-27

申请人： Xuemei Ouyang ,  Pen Li ,  Monisha Ghosh

发明人： Xuemei Ouyang ,  Pen Li ,  Monisha Ghosh

IPC分类号： H04L5/12

CPC分类号： H04L1/06 ,  H04L25/03197

摘要： A system and method for a simplified Maximum Likelihood (ML) decoding (203) for MIMO systems is provided. The full ML decoding gives the lower bound of the decoding for CC coded MIMO systems. However, the computation cost is too high to be implemented in real system. Many alternative methods have been proposed for the decoding. Among them, weighted Zero Forcing (WZF) is one that can give affordable performance with reasonable computation complexity but there are several dB of performance gap for the WZF decoding and ML decoding. This present invention discloses a decoding system and method having improved performance over WZF decoding with affordable implementation complexity.

摘要翻译： 提供了一种用于MIMO系统的简化最大似然（ML）解码（203）的系统和方法。 完整的ML解码为CC编码的MIMO系统提供了解码的下限。 然而，计算成本太高，无法在实际系统中实现。 已经提出了用于解码的许多替代方法。 其中，加权零强制（WZF）是能够以合理的计算复杂度提供负担得起的性能，但对于WZF解码和ML解码，存在几dB的性能差距。 本发明公开了一种具有可靠实现复杂度的WZF解码性能提高的解码系统和方法。

公开(公告)号：US20100035568A1

公开(公告)日：2010-02-11

申请号：US12529409

申请日：2008-03-06

申请人： Monisha Ghosh

发明人： Monisha Ghosh

IPC分类号： H04B1/18

CPC分类号： H04L27/063 ,  H04B1/719 ,  H04L5/0007 ,  H04L5/0032 ,  H04L27/0014 ,  H04L27/2647 ,  H04L2027/0028 ,  H04L2027/0087 ,  H04L2027/0097

摘要： To quickly and robustly detect the presence of an incumbent user and rapidly relinquish the spectrum to the incumbent user when necessary, carrier recovery is performed in a receiver of the secondary user's cognitive or software radio prior to performing correlation detection with an upsampled reference signal to correct for large frequency offsets and improve the performance of the correlation detector. To detect a received signal, a pilot value is added to a reference signal. The reference signal is upsampled to a sampling frequency of the received signal. The upsampled reference signal is correlated with a demodulated baseband signal to produce a correlation value. It is then determined whether the received signal is present if the correlation value is greater than a predetermined detection threshold value.

摘要翻译： 为了快速且鲁棒地检测现有用户的存在并且在必要时快速将频谱放弃给现有用户，在用上采样的参考信号执行相关检测之前，在次用户的认知或软件无线电的接收机中执行载波恢复以校正 用于大频率偏移并提高相关检测器的性能。 为了检测接收到的信号，将导频值加到参考信号。 参考信号被上采样到接收信号的采样频率。 上采样参考信号与解调的基带信号相关，以产生相关值。 然后，如果相关值大于预定检测阈值，则确定接收信号是否存在。

公开(公告)号：US07411928B2

公开(公告)日：2008-08-12

申请号：US10537221

申请日：2003-11-18

申请人： Monisha Ghosh ,  Xuemei Ouyang

发明人： Monisha Ghosh ,  Xuemei Ouyang

IPC分类号： H04Q7/00

CPC分类号： H04L1/0071 ,  H04B7/0854 ,  H04L1/0054 ,  H04L1/06 ,  H04L27/2601

摘要： Multiple input multiple output (MIMO) systems are candidates for higher data rate wireless communication systems. Currently, for a single input single output (SISO) 1802.11a system can provide a transmission data rate up to 54 Mbps. The present invention is a 2 by 2 Multiple In Multiple Out (MIMO) system having a decoding apparatus that increases the data rate to over 100 Mbps but at a computation cost about the same as for optimal decoding for a SISO system and 1/64 of the optimal decoding for a 2 by 2 MIMO system. At a bit error rate (BER) of 10-4 level, the 2 by 2 MIMO system of the present invention provides double the transmission data rate of the SISO system with approximately the same signal to noise ratio (SNR).

摘要翻译： 多输入多输出（MIMO）系统是更高数据速率无线通信系统的候选者。 目前，对于单输入单输出（SISO）1802.11a系统，可提供高达54 Mbps的传输数据速率。 本发明是一种具有将数据速率提高到100Mbps以上的解码装置的2乘2多输出多输出系统，其计算成本与用于SISO系统的最佳解码相同，计算成本约为1/64 2×2 MIMO系统的最优解码。 在10-4级别的误码率（BER）的情况下，本发明的2×2 MIMO系统以大致相同的信噪比（SNR）提供SISO系统的传输数据速率的两倍。

公开(公告)号：US07236548B2

公开(公告)日：2007-06-26

申请号：US10185385

申请日：2002-06-28

申请人： Monisha Ghosh ,  Joseph Patrick Meehan ,  Xuemei Ouyang

发明人： Monisha Ghosh ,  Joseph Patrick Meehan ,  Xuemei Ouyang

IPC分类号： H04B7/10 ,  H04L1/02

CPC分类号： H04L1/0059 ,  H04B7/0885 ,  H04L1/0054 ,  H04L1/0071 ,  H04L1/06 ,  H04L25/0204 ,  H04L27/2647

摘要： Bit level, rather than symbol level, diversity combining is employed within a wireless communications receiver. Channel estimates and bit metrics are separately computed for signals received by different antenna elements. Bit metrics are calculated by determining a least squares cumulative difference between all bits within the received symbol and corresponding bits within constellation symbols as modified by the channel estimate. The separately-determined bit metrics are then combined for decoding. Performance improvements over both single antenna systems and multiple antenna systems with symbol level diversity combining are achieved.

摘要翻译： 在无线通信接收机内采用比特级而不是符号级，分集组合。 针对由不同天线元件接收的信号，分别计算信道估计和比特度量。 通过确定接收符号内的所有比特和由信道估计修改的星座符号内的相应比特来计算比特度量。 然后将单独确定的位度量组合用于解码。 实现了具有符号级分集组合的单天线系统和多天线系统的性能改进。

公开(公告)号：US07206352B2

公开(公告)日：2007-04-17

申请号：US10078933

申请日：2002-02-19

申请人： Dagnachew Birru ,  Vasanth R. Gaddam ,  Monisha Ghosh

发明人： Dagnachew Birru ,  Vasanth R. Gaddam ,  Monisha Ghosh

IPC分类号： H04L23/02 ,  H04L5/12

CPC分类号： H04L1/007 ,  H04L1/0059 ,  H04N19/89 ,  H04N21/2383 ,  H04N21/4382 ,  H04N21/631

摘要： This disclosure describes a flexible digital transmission system that improves upon the ATSC A/53 HDTV signal transmission standard. The system includes a digital television signal transmitter for generating a first Advanced Television Systems Committee (ATSC) standard 8-VSB bit stream and, for generating an encoded new bit stream capable of transmitting high priority information bits, wherein symbols of the new bit stream are capable of being transmitted according to a transmission mode selected from group comprising: a 2-VSB mode, a 4-VSB mode, and a hierarchical-VSB (H-VSB) transmission mode. Each respective 2-VSB, 4-VSB, and H-VSB mode is characterized as having symbols mapped according to possible symbol values from an alphabet comprising respectively, {−7, −5, 5, 7}, {7, 3, −3, −7}, and {7, 5, 3, −3, −5, −7}. The standard 8-VSB bit stream and new bit stream may be simultaneously transmitted over a terrestrial channel according to a broadcaster defined bit-rate ratio.

摘要翻译： 本公开描述了一种改进了ATSC A / 53 HDTV信号传输标准的灵活数字传输系统。 该系统包括用于产生第一高级电视系统委员会（ATSC）标准8-VSB比特流的数字电视信号发射机，用于产生能够发送高优先级信息比特的编码新比特流，其中新比特流的符号是 能够根据从包括2-VSB模式，4-VSB模式和分级VSB（H-VSB）传输模式的组中选择的传输模式进行传输。 每个相应的2-VSB，4-VSB和H-VSB模式的特征在于具有根据分别由{-7,5 -5,7}，{7,3，...， 3，-7}和{7，5，3，-3，-5，-7}。 标准8-VSB比特流和新比特流可以根据广播器定义的比特率比率通过地面信道同时发送。

公开(公告)号：US20060126489A1

公开(公告)日：2006-06-15

申请号：US10538577

申请日：2003-12-05

申请人： Xuemei Quyang ,  Monisha Ghosh

发明人： Xuemei Quyang ,  Monisha Ghosh

IPC分类号： H04J11/00

CPC分类号： H04L1/0625 ,  H04L1/06 ,  H04L27/2602 ,  H04L27/2626

摘要： A transmitter (20) of an OFDM system (10) splits a data input signal into a pair of OFDM subcarrier streams (S0, S1). The transmitter further implements a cross subcarrier transmitter diversity encoding of the OFDM subcarrier streams (S0, S1). The result is a pair of encoded OFDM subcarrier stream (ES0, ES1) that are transformed into modulated transmitter signals (s0, s1), respectively, which are transmitted to a receiver antenna (60) via an transmitter antenna (50) and a transmitter antenna (51), respectively.

摘要翻译： OFDM系统（10）的发射机（20）将数据输入信号分成一对OFDM子载波流（S 0，S 1）。 发射机进一步实现OFDM子载波流（S 0，S 1）的跨子载波发射机分集编码。 结果是分别被转换成调制发射机信号（s 0，...，S 1）的一对编码OFDM子载波流（ES 0，ES 1），它们是 分别经由发射机天线（50）和发射机天线（51）发射到接收机天线（60）。

公开(公告)号：US20060092882A1

公开(公告)日：2006-05-04

申请号：US10537221

申请日：2003-11-18

申请人： Monisha Ghosh ,  Xuemei Quyang

发明人： Monisha Ghosh ,  Xuemei Quyang

IPC分类号： H04Q7/00

CPC分类号： H04L1/0071 ,  H04B7/0854 ,  H04L1/0054 ,  H04L1/06 ,  H04L27/2601

摘要： Multiple input multiple output (MIMO) systems are candidates for higher data rate wireless communication systems. Currently, for a single input single output (SISO) 1802.11a system can provide a transmission data rate up to 54 Mbps. The present invention is a 2 by 2 Multiple In Multiple Out (MIMO) system having a decoding apparatus that increases the data rate to over 100 Mbps but at a computation cost about the same as for optimal decoding for a SISO system and 1/64 of the optimal decoding for a 2 by 2 MIMO system. At a bit error rate (BER) of 10-4 level, the 2 by 2 MIMO system of the present invention provides double the transmission data rate of the SISO system with approximately the same signal to noise ratio (SNR).

摘要翻译： 多输入多输出（MIMO）系统是更高数据速率无线通信系统的候选者。 目前，对于单输入单输出（SISO）1802.11a系统，可提供高达54 Mbps的传输数据速率。 本发明是一种具有将数据速率提高到100Mbps以上的解码装置的2乘2多输出多输出系统，其计算成本与用于SISO系统的最佳解码相同，计算成本约为1/64 2×2 MIMO系统的最优解码。 在10-4级别的误码率（BER）的情况下，本发明的2×2 MIMO系统以大致相同的信噪比（SNR）提供SISO系统的传输数据速率的两倍。

公开(公告)号：US07027538B2

公开(公告)日：2006-04-11

申请号：US10075312

申请日：2002-02-14

申请人： Monisha Ghosh

发明人： Monisha Ghosh

IPC分类号： H04B1/10

CPC分类号： H04L1/0047 ,  H04L1/0054 ,  H04L2025/03375 ,  H04L2025/0349

摘要： A method and system for performing joint equalization and decoding of Complementary Code Key (CCK) encoded symbols. The system comprises: a decision feedback equalizer (DFE) structure for simulating an inverse communications channel response and providing an output comprising an estimation of the received symbols, the DFE structure including a forward equalizer path and a feedback equalizer path including a feedback filter; and, a CCK decoder embedded in the feedback path and operating in conjunction with a feedback filter therein for decoding the chips based on intermediate DFE outputs including those chips corresponding to past decoded CCK symbols. Decisions on a symbol chip at a particular time are not made until an entire CCK codeword that the chip belongs to is decoded, thereby reducing errors propagated when decoding the symbols. Advantageously, the trellis decoding method is implemented as a computationally efficient 64-state trellis.

公开(公告)号：US5881363A

公开(公告)日：1999-03-09

申请号：US641152

申请日：1996-04-29

申请人： Monisha Ghosh ,  Samir N. Hulyalkar

发明人： Monisha Ghosh ,  Samir N. Hulyalkar

IPC分类号： H04B3/10 ,  H04B15/00 ,  H04H20/78 ,  H04J11/00 ,  H04L25/03 ,  H04L25/497 ,  H04N7/10 ,  H04N7/173

CPC分类号： H04H20/12 ,  H04H20/78 ,  H04L25/03146 ,  H04L25/03343 ,  H04L25/497 ,  H04L25/4975 ,  H04N7/102 ,  H04N7/17309 ,  H04L2025/03808

摘要： In a CATV return channel between a transmitter and a headend receiver, the transmitter is provided with a precoder having programmable but fixed coefficients. The receiver is provided with an ingress rejection filter (IRF) having programmable but fixed coefficients. A non-precoded training sequence is sent from the transmitter to the receiver during a training interval. A multipath and an ingress in the CATV return channel are estimated at the receiver based upon the training sequence sent by the transmitter and received by the receiver. The precoder coefficients and the IRF coefficients are calculated and the precoder and the ingress rejection filter are programmed with the calculated coefficients, respectively. The precoder and the ingress rejection filter use the respective calculated coefficients during a data transmission interval to simultaneously compensate for undesirable effects of multipath and ingress noise in the CATV return channel during data transmission from the transmitter to the headend.

摘要翻译： 在发射机和前端接收机之间的CATV返回信道中，发射机设置有具有可编程但固定系数的预编码器。 接收器设置有具有可编程但固定系数的入口抑制滤波器（IRF）。 在训练间隔期间，从发射机向接收机发送非预编码训练序列。 基于由发射机发送并由接收机接收的训练序列，在接收机处估计CATV返回信道中的多路径和入口。 计算预编码器系数和IRF系数，分别用计算出的系数对预编码器和入侵抑制滤波器进行编程。 预编码器和入口抑制滤波器在数据传输间隔期间使用相应的计算系数，以在从发射机到头端的数据传输期间同时补偿CATV返回信道中的多路径和入口噪声的不期望的影响。