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61. 发明授权

US5968199A High performance error control decoder 失效
标题翻译：高性能错误控制解码器
公开(公告)号：US5968199A
公开(公告)日：1999-10-19
申请号：US768530
申请日：1996-12-18
申请人： Ali S. Khayrallah , Raymond L. Toy , Sandeep Chennakeshu
发明人： Ali S. Khayrallah , Raymond L. Toy , Sandeep Chennakeshu
IPC分类号： G10L19/00 , H03M13/00 , H03M13/03 , H03M13/15 , H03M13/37 , H03M13/39 , H03M13/43 , H03M13/45
CPC分类号： H03M13/45 , H03M13/00 , H03M13/1505 , H03M13/151 , H03M13/3738 , H03M13/616 , H03M13/618 , H03M13/6577 , H03M13/658 , G10L19/005
摘要： An error control decoder receives a received vector to be decoded. The decoder then calculates, as an error estimate, the Euclidean distance between a codeword choice and the received vector. The output error estimate is appropriately scaled and quantized in accordance with the particular code being processed by the decoder. The efficient Conway-Sloane algorithm is extended for use in connection with the decoding of shortened Golay codes. A modification is made to the generator matrix for the Golay code to produce a modified generator matrix that is unique for each shortened code. The modified generator matrix is then implemented in the Conway-Sloane algorithm to identify the best codeword for conversion to its corresponding information bits for output.
摘要翻译：误差控制解码器接收要被解码的接收矢量。解码器然后计算码字选择和接收向量之间的欧几里德距离作为误差估计。根据由解码器处理的特定代码适当地缩放和量化输出误差估计。有效的Conway-Sloane算法被扩展用于与缩短的Golay码的解码结合使用。对于Golay码的发生器矩阵进行修改以产生对于每个缩短的代码是唯一的修改的生成器矩阵。然后，以Conway-Sloane算法实现修改后的生成矩阵，以识别用于转换为其相应信息比特以输出的最佳码字。

62. 发明授权

US5918174A Circuitry and method for initiating communication between communication stations of a radio communication system 失效
标题翻译：用于发起无线电通信系统的通信站之间的通信的电路和方法
公开(公告)号：US5918174A
公开(公告)日：1999-06-29
申请号：US626182
申请日：1996-03-29
申请人： Sandeep Chennakeshu , Yi-Pin Eric Wang , Kumar Balachandran
发明人： Sandeep Chennakeshu , Yi-Pin Eric Wang , Kumar Balachandran
IPC分类号： H04B7/185 , H04W68/00 , H04W68/02 , H04W88/18
CPC分类号： H04B7/18558 , H04W68/00 , H04W68/02 , H04W88/185
摘要： A method and associated circuitry for initiating communication between a network station and a user terminal of a radiotelephonic communication system, such as a satellite-cellular communication system. When communication is to be initiated, a paging signal is transmitted by a network station to the user terminal. When the user terminal detects the paging signal, an acknowledgment signal is generated by the user terminal and encoded to increase the margin of the acknowledgment signal. An increased-margin acknowledgment signal acknowledging reception of the paging signal is transmitted to facilitate communication of the acknowledgment signal back to the network station.
摘要翻译：一种用于发起无线电通信系统（诸如卫星蜂窝通信系统）的网络站和用户终端之间的通信的方法和相关电路。当要发起通信时，网络站向用户终端发送寻呼信号。当用户终端检测到寻呼信号时，用户终端产生一个确认信号并进行编码以增加确认信号的余量。发送确认寻呼信号的接收的增加的裕度确认信号以促进确认信号的通信回到网络站。

63. 发明授权

US5835480A Circuitry and method for simultaneously transmitting voice and data information 失效
标题翻译：同时发送语音和数据信息的电路和方法
公开(公告)号：US5835480A
公开(公告)日：1998-11-10
申请号：US729090
申请日：1996-10-15
申请人： Sandeep Chennakeshu
发明人： Sandeep Chennakeshu
IPC分类号： H04L27/34 , H04M3/00 , H04M11/06 , H04J11/00
CPC分类号： H04M11/06 , H04L27/3472
摘要： Circuitry, and an associated method, for permitting simultaneous transmission of multiple forms of information, such as that generated during operation of a multi-media communication device. Signal bits of the different forms of information are together mapped onto symbols of a multi-level, multi-phase modulation symbol set. Transmission of signals representative of the symbols are transmitted, thereby to effectuate the simultaneous transmission of the multiple forms of information.
摘要翻译：电路和相关方法，用于允许同时传输多种形式的信息，诸如在多媒体通信设备的操作期间产生的信息。不同形式信息的信号位一起映射到多级多相位调制符号集合的符号上。发送表示符号的信号的传输，从而实现多种形式的信息的同时传输。

64. 发明授权

US5752204A Antenna assembly for radiotelephonic device 失效
标题翻译：无线电设备天线组件
公开(公告)号：US5752204A
公开(公告)日：1998-05-12
申请号：US625312
申请日：1996-04-01
申请人： Darrell Epperson , Sandeep Chennakeshu , Peter Dimitrios Karabinis
发明人： Darrell Epperson , Sandeep Chennakeshu , Peter Dimitrios Karabinis
IPC分类号： H01Q1/08 , H01Q1/24 , H01Q21/28 , H04B1/38 , H04B7/185 , H04M1/02 , H04B1/08
CPC分类号： H01Q1/243 , H01Q1/242 , H01Q21/28 , H04B1/3833 , H04B7/18571
摘要： An antenna assembly, and an associated method, facilitates communication of a radiotelephone operable in a satellite communication system, such as a satellite-cellular communication system. A patch antenna is rotatably coupled to a radiotelephonic housing of the radiotelephone. The patch antenna exhibits circular polarization characteristics, best to detect and to transmit communication signals to a satellite-based transceiver. By positioning patch antennas at opposing sides of the radiotelephone, down-link signals transmitted to the radiotelephone are detectable irrespective of the orientation of the radiotelephone.
摘要翻译：天线组件和相关联的方法有助于在诸如卫星蜂窝通信系统的卫星通信系统中可操作的无线电话机的通信。贴片天线可旋转地联接到无线电话机的无线电通话外壳。贴片天线具有圆极化特性，最好检测和传输通信信号到卫星收发器。通过在无线电话机的相对侧定位贴片天线，无论无线电话机的方向如何，都可以检测到发射到无线电话机的下行链路信号。

65. 发明授权

US5661724A Satellite diversity scheme 失效
标题翻译：卫星多样性方案
公开(公告)号：US5661724A
公开(公告)日：1997-08-26
申请号：US574141
申请日：1995-12-18
申请人： Sandeep Chennakeshu , Amer A. Hassan , Barbara Molnar , Karl Molnar , Rajaram Ramesh
发明人： Sandeep Chennakeshu , Amer A. Hassan , Barbara Molnar , Karl Molnar , Rajaram Ramesh
IPC分类号： H04B7/212 , H04B7/185 , H04B7/195
CPC分类号： H04B7/18534
摘要： A diversity scheme for allowing a transmitter/receiver, such as a mobile unit in a mobile telecommunications system, to exchange communication signals with more than one control station, such as a base station or satellite. According to an exemplary embodiment of the diversity scheme, the mobile unit scans for the control channel of a second satellite during idle time slots while communicating with a first satellite during active time slots. Once the mobile unit detects a control channel from a second satellite, the mobile unit stores synchronization information and establishes a communication link with the second satellite if shadowing or other severe fading causes signal quality over a communication link established with a first satellite to fall below a threshold level. The diversity scheme also allows the mobile unit to communicate simultaneously with two satellites, using alternate TDMA frames.
摘要翻译：用于允许诸如移动电信系统中的移动单元的发射机/接收机与诸如基站或卫星的多于一个控制站交换通信信号的分集方案。根据分集方案的示例性实施例，移动单元在空闲时隙期间扫描第二卫星的控制信道，同时在活动时隙期间与第一卫星通信。一旦移动单元检测到来自第二卫星的控制信道，则移动单元存储同步信息并与第二卫星建立通信链路，如果阴影或其他严重衰落导致通过与第一卫星建立的通信链路的信号质量降至低于门限等级。分集方案还允许移动单元使用备用TDMA帧同时与两颗卫星通信。

66. 发明授权

US5467374A Low complexity adaptive equalizer for U.S. digital cellular radio receivers 失效
标题翻译：用于美国数字蜂窝无线电接收机的低复杂度自适应均衡器
公开(公告)号：US5467374A
公开(公告)日：1995-11-14
申请号：US143028
申请日：1993-10-29
申请人： Sandeep Chennakeshu , Paul W. Dent , Ravinder D. Koilpillai , Raymond L. Toy
发明人： Sandeep Chennakeshu , Paul W. Dent , Ravinder D. Koilpillai , Raymond L. Toy
IPC分类号： H04L25/03 , H03D1/00
CPC分类号： H04L25/03197 , H04L2025/0356 , H04L2025/03796
摘要： A low complexity adaptive equalizer for use in U.S. digital cellular radios demodulates .pi./4-shifted differentially encoded quadrature phase shift keyed (DQPSK) encoding in the presence of intersymbol interference (ISI) with reduced decoding complexity by employing an estimated received constellation which takes into account channel changes over time and ISI. The decoding complexity is reduced by tracking a reduced number of estimated reference constellation points and taking advantage of the geometry to estimate the remaining symbol constellation points. A slot of symbols is decoded, employing unique filtering, in segments from the beginning in a forward direction and from the end in a reverse direction meeting at a fade point. This isolates a fade and allows the equalizer to perform more reliably.
摘要翻译：用于美国数字蜂窝无线电的低复杂度自适应均衡器在存在码间干扰（ISI）的情况下，通过采用估计的接收星座来解调具有降低的解码复杂度的π/ 4位差分编码正交相移键控（DQPSK）编码帐户频道随时间变化和ISI。通过跟踪估计的参考星座点的数量减少并利用几何来估计剩余的符号星座点来降低解码复杂度。符号的时隙被解码，采用独特的滤波，从开始的前进方向开始，并且在反向方向的结束处，在渐变点处会聚。这样隔离了一个淡入淡出，并允许均衡器执行得更可靠。

67. 发明授权

US5465271A Post detection weighted vector combining diversity receivers using phase metrics for mobile and indoor radio channels 失效
标题翻译：使用移动和室内无线电信道的相位度量的后检测加权向量组合分集接收机
公开(公告)号：US5465271A
公开(公告)日：1995-11-07
申请号：US109553
申请日：1993-08-20
申请人： Stephen M. Hladik , Sandeep Chennakeshu
发明人： Stephen M. Hladik , Sandeep Chennakeshu
IPC分类号： H04B7/08 , H04L1/06 , H04B7/02 , H04L1/02
CPC分类号： H04B7/0865 , H04B7/0885 , H04L1/06
摘要： A digital radio communications system employs a digital information source for providing digital information such as message bits, a transmitter for transmitting encoded digital information into data symbols in a radio-frequency (RF) signal to a plurality of antennae which sense the transmitted RF signal. A post detection measure of signal quality, the signal-to-impairment ratio, (SIR), is utilized by the receiver to perform post detection combining of signals received by a plurality of antennae. The antennae are coupled to a receiver which for each received signal: digitizes the signal, determines phase angles of the digitized signal, converts the signal to unit vectors, determines a signal-to-impairment ratio (SIR) estimates .gamma..sup.j of the digitized signals. The SIR estimate .gamma..sup.j is weighted by combining weight computation element and multiplied by each unit vector to provide an in-phase is component and a quadrature component for each signal. The in-phase components are combined into a in-phase composite signal I.sub.c (n). The quadrature-phase components are combined into a quadrature-phase composite signal Q.sub.c (n). The composite signal (I.sub.c (n), Q.sub.c (n) is then decoded into phase angles which are reversed mapped to message bits which are utilized by an output device resulting in a radio communication system exhibiting improved performance during radio "fade" periods.
摘要翻译：数字无线电通信系统采用数字信息源来提供诸如消息比特之类的数字信息，用于将编码的数字信息发送到射频（RF）信号中的数据符号的发射机发送到感测发射的RF信号的多个天线。接收机利用信号质量的信号质量（SIR）的后检测措施来执行由多个天线接收的信号的后检测组合。天线被耦合到接收器，对于每个接收的信号：数字化信号，确定数字化信号的相位角，将信号转换为单位矢量，确定数字化信号的信噪比（SIR）估计γj 。 SIR估计γj通过组合权重计算元素并乘以每个单位向量来加权，以为每个信号提供同相分量和正交分量。同相分量被组合成同相复合信号Ic（n）。正交相位分量被组合成正交相位复合信号Qc（n）。然后，复合信号（Ic（n），Qc（n））被解码成被反向映射到由输出设备使用的消息位的相位角，导致在无线电“衰落”周期期间表现出改善的性能的无线电通信系统。

68. 发明授权

US5400362A Double sided slot traversing decoding for time division multiple access (TDMA) radio systems 失效
标题翻译：用于时分多址（TDMA）无线电系统的双面时隙遍历解码
公开(公告)号：US5400362A
公开(公告)日：1995-03-21
申请号：US39599
申请日：1993-03-29
申请人： Sandeep Chennakeshu , Raymond L. Toy , Ravinder D. Koilpillai
发明人： Sandeep Chennakeshu , Raymond L. Toy , Ravinder D. Koilpillai
IPC分类号： H04L1/20 , H04L25/03 , H04J3/16 , H04J3/06
CPC分类号： H04L1/20 , H04L2025/0356 , H04L25/03178
摘要： A digital time division multiple access (TDMA) radio communications system employs a digital information source for providing digital information, a transmitter for transmitting encoded digital information in a radio-frequency (RF) signal to a receiver which demodulates the encoded symbols into digital information to be utilized by an output device. The receiver, synchronizes, compensates for frequency drift, samples and divides the samples into halfslots of samples. The halfslots are subdivided into subslots numbered from 1 to N, where N represents the last received subslot. Subslots 1 and N are demodulated into digital information in a forward and reverse direction, respectively with metrics calculated. If the metrics indicate a signal with a larger signal-to-noise ratio from subslot N, subslot N-1 is demodulated in a reverse sense with another reverse metric calculated, and vice versa. This process of extending demodulation in the direction of greater signal strength is repeated until all subslots in the slot have been demodulated. A second embodiment passes through all subslots in a forward and reverse direction calculating subslot metrics. The subslot metrics are summed into a halfslot metrics. The best halfslot metric indicates the sense of demodulation of each subslot. The digital information is then dumped in the proper order and sense to an output device which utilizes the digital information resulting in increased performance during fade periods.
摘要翻译：数字时分多址（TDMA）无线通信系统采用数字信息源提供数字信息，发射机用于将射频（RF）信号中的编码数字信息发射到接收机，该接收机将编码符号解调为数字信息，由输出设备使用。接收机同步，补偿频率漂移，采样并将样品分成样品半槽。半槽被细分为从1到N的子槽，其中N表示最后接收的子槽。分别将子空间1和N按正向和反向方向分别解调成数字信息。如果度量指示具有来自子时隙N的更大的信噪比的信号，则在具有反向意义上的子载波N-1中使用另一个反向度量计算解调，反之亦然。重复在更大的信号强度的方向上扩展解调的过程，直到时隙中的所有子时隙已被解调为止。第二实施例在向前和向后的方向上通过所有子时隙计算子时间度量。子时间度量被总计为半数指标。最佳半时隙度量表示每个子时隙的解调感。然后将数字信息以适当的顺序和感觉倾倒到使用数字信息的输出设备，从而在淡化时段期间提高性能。

69. 发明授权

US5363407A Transmitter optimization for spectrally congested radio communication systems 失效
标题翻译：频谱拥塞无线电通信系统的发射机优化
公开(公告)号：US5363407A
公开(公告)日：1994-11-08
申请号：US939747
申请日：1992-09-02
申请人： Rajaram Ramesh , Sandeep Chennakeshu
发明人： Rajaram Ramesh , Sandeep Chennakeshu
IPC分类号： H04B1/04 , H04B15/00 , H04B14/04
CPC分类号： H04B15/00 , H04B1/0475
摘要： A method of configuring an optimum communication system for communicating on adjacent frequency bands with minimal interference between adjacent channels comprises serially coupling a selected encoder to a mapper, a transmit filter, a low pass filter and a modulator, and constructing a receiver with a seriallycoupled receive filter and decoder. The transmit filter is optimized by choosing transmit filter coefficients d.sub.opt which maximize the inband to adjacent-band power. Transmitter coefficients d.sub.opt are obtained by solving an eigenvalue problem which takes into account the power spectrum of the encoder, mapper and receive filter. The optimum transmitter coefficients are then employed in the transmitter to shape the transmitted signal, increasing the adjacent channel interference protection ratio (ACIPR). In an alternative embodiment, further constraints are placed upon the system, such as reducing the combined impulse response of the transmit filter, low pass filter and the receive filter to zero at the beginning of subsequent symbol periods. The resulting system then exhibits an increased ACIPR along with a reduced intersymbol interference.
摘要翻译：配置用于以相邻信道之间的最小干扰在相邻频带上通信的最佳通信系统的方法包括将所选择的编码器串行耦合到映射器，发射滤波器，低通滤波器和调制器，以及构造具有串联接收的接收机滤波器和解码器。通过选择将带内最大化为相邻带功率的发射滤波器系数dopt来优化发射滤波器。通过求解考虑到编码器，映射器和接收滤波器的功率谱的特征值问题来获得发射机系数dopt。然后在发射机中采用最佳发射机系数来对发射信号进行整形，增加相邻信道干扰保护比（ACIPR）。在替代实施例中，进一步的约束被放置在系统上，诸如在随后的符号周期开始时将发射滤波器，低通滤波器和接收滤波器的组合脉冲响应减小到零。所得到的系统随后表现出增加的ACIPR以及减少的符号间干扰。

70. 发明授权

US5351274A Post detection selection combining diversity receivers for mobile and indoor radio channels 失效
标题翻译：后检测选择组合用于移动和室内无线电信道的分集接收机
公开(公告)号：US5351274A
公开(公告)日：1994-09-27
申请号：US109556
申请日：1993-08-20
申请人： Sandeep Chennakeshu , Stephen M. Hladik , Gary J. Saulnier , Ravinder D. Koilpllai , Raymond L. Toy
发明人： Sandeep Chennakeshu , Stephen M. Hladik , Gary J. Saulnier , Ravinder D. Koilpllai , Raymond L. Toy
IPC分类号： H03M13/00 , H03M13/23 , H04B7/08 , H04B7/26 , H04B15/00 , H04L1/00 , H04L1/06 , H04L1/20 , H04L27/00 , H04B7/04
CPC分类号： H04L1/20 , H04B7/082 , H04L1/06
摘要： A method of estimating the quality of a communication channel from a differential phase angle between a received signal and the corresponding transmitted phase angle employs determining a signal to impairment ratio (SIR) as an indicator of channel state information (CSI). A maximum likelihood estimation procedure is employed to calculate this CSI metric as a function of the differential phase angle between be received signal and transmitted signal An alternate embodiment employs an estimation that incorporates average SIR information for a Rayleigh fading channel. Since CSI is derived from the phase angle of the received signal, and does not require signal amplitude information, it is attractive for use with differential detectors, phase-locked loops (PLLs) and hard-limited signals. The CSI provided can be used for implementing post detection selection diversity, by selecting the signal from a plurality of antennae which has the best SIR.
摘要翻译：从接收信号和对应的发射相位角之间的差分相位角估计通信信道的质量的方法使用将信号衰减比（SIR）确定为信道状态信息（CSI）的指示符。采用最大似然估计程序来计算作为接收信号和发射信号之间的差分相位角的函数的该CSI度量。替代实施例采用包含瑞利衰落信道的平均SIR信息的估计。由于CSI是从接收信号的相位角导出的，并且不需要信号幅度信息，因此与差分检测器，锁相环（PLL）和硬限制信号一起使用是有吸引力的。所提供的CSI可以用于通过选择具有最佳SIR的多个天线的信号来实现后检测选择分集。

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