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    • 82. 发明授权
    • Method and apparatus for using Walsh shift keying in a spread spectrum
communication system
    • US5602833A
    • 1997-02-11
    • US358425
    • 1994-12-19
    • Ephraim Zehavi
    • Ephraim Zehavi
    • H04B7/15H04B7/216H04J11/00H04L1/12H04L27/30H04Q7/22H04Q7/24H04Q7/26H04Q7/30H04J13/02H04L27/28
    • H04J13/0074H04B7/216H04J13/0048H04J13/102
    • Method and apparatus for generating orthogonally encoded communication signals for communication system subscribers using multiple orthogonal functions for each orthogonal communication channel. Digital data symbols for signal recipients are M-ary modulated using at least two n-length orthogonal modulation symbols, which are generally Walsh functions normally used within the communication system. These symbols are provided by a modulation symbol selector (124) typically from one or more code generators (126, 128), and the modulation is such that M equals a product of a total number of orthogonal functions and the number used to generate individual modulation symbols. Each group of log M encoded data symbols from data processing elements (100, 102) are mapped into one modulation symbol using the modulation symbol selection element (124) according to their binary values. In some embodiments, a fast Hadamard transformer is used for symbol mapping. The resulting communication signals are demodulated by correlating them with the preselected number of orthogonal functions, in parallel, and demodulating the results into M energy values representing each orthogonal modulation symbol. The energy values are mapped into energy metric data using a dual maximum metric generation process. The correlation and demodulation can be accomplished using at least two sets of N correlators (142), N being the number of functions used, and applying correlated signals to one demodulator for each set of correlators (144). Each demodulator outputs M energy values representing each of the M mutually orthogonal modulation symbols, which are then combined into a single set of M energy values. In further configurations, coherent demodulators (172, 174) can be used to produce amplitude values for received signals which are then combined (178) with dual maximum metric results (170) to produce composite metric values for data symbols (178).
    • 85. 发明授权
    • Symbol and frame synchronization in both a TDMA system and a CDMA
    • TDMA系统和CDMA中的符号和帧同步
    • US5590160A
    • 1996-12-31
    • US387031
    • 1995-02-10
    • Kjell Ostman
    • Kjell Ostman
    • H04B7/26H03H21/00H04B1/707H04B7/005H04B7/216H04J3/00H04L7/00H04L7/04H04L7/08H04L27/22H04Q7/38H04L7/02H04L27/30
    • H04B1/7085H04L7/042H04L7/043H04B1/70735
    • A digital radio communication system includes a receiver for receiving a signal stream that includes data frames, each frame including a data signal sequence and a synchronizing signal sequence. The communication system synchronizes the receiver by employing the signal stream. The receiver comprises: a sampling circuit for sampling symbol levels in the synchronizing signal sequence; cross correlation circuitry for comparing values derived from the sampled symbol levels with an expected set of values and producing an error value output; and correction circuitry that is responsive to the error output and produces a sample control output to the sample circuitry to alter the times of sampling of the symbol levels so as to reduce the error output and achieve time synchronization with the received synchronizing signal sequence. A further embodiment of the invention is described in relation to a CDMA receiving system.
    • 数字无线电通信系统包括用于接收包括数据帧的信号流的接收机,每个帧包括数据信号序列和同步信号序列。 通信系统通过采用信号流来同步接收机。 接收机包括:采样电路,用于对同步信号序列中的符号电平进行采样; 互相关电路,用于将从采样符号级别导出的值与期望的值集合进行比较并产生误差值输出; 以及校正电路,其响应于所述误差输出并且产生对所述采样电路的采样控制输出,以改变所述符号电平的采样次数,以便减少所述误差输出并实现与所接收的同步信号序列的时间同步。 关于CDMA接收系统描述本发明的另一实施例。
    • 86. 发明授权
    • Split band processing for spread spectrum communications
    • 分频频带处理扩频通信
    • US5579335A
    • 1996-11-26
    • US534574
    • 1995-09-27
    • Philip H. SutterlinJ. Marcus Stewart
    • Philip H. SutterlinJ. Marcus Stewart
    • H04B1/707H04B3/54H04L25/03H04L27/30
    • H04B1/707H04B3/54H04L25/03019H04B2203/5408H04B2203/542
    • A method and apparatus for compensating for distortion in a spread spectrum communications system particularly useful where the spread spectrum is transmitted over a power line. The information carrying signal (ICS) is split into two sub-bands and the ICS in one sub-band (or a correlation value determined from the ICS in that sub-band) is delayed relative to the other sub-band. The ICS (or correlation values) from the two sub-bands are recombined after the delay and processed in an ordinary manner. The time delay is selected so as to compensate for the distortion. In one embodiment, the correlation peaks in each of the sub-bands are examined and the time delay is determined by, in effect, aligning the peaks in the two sub-bands in time so that when the two sub-bands are combined, a sharper correlation peak is obtained.
    • 一种用于补偿扩频通信系统中的失真的方法和装置,其特征在于在电力线上传播扩频。 信息携带信号(ICS)被分成两个子带,并且一个子带中的ICS(或从该子带中的ICS确定的相关值)相对于另一个子带延迟。 来自两个子带的ICS(或相关值)在延迟之后重新组合并以常规方式处理。 选择时间延迟以补偿失真。 在一个实施例中,检查每个子带中的相关峰值,并且通过实际上确定时间上两个子带中的峰值来确定时间延迟,使得当两个子带被组合时, 获得更锐利的相关峰值。
    • 88. 发明授权
    • Method and apparatus for providing a communication link quality
indication
    • 用于提供通信链路质量指示的方法和装置
    • US5469471A
    • 1995-11-21
    • US190517
    • 1994-02-01
    • Charles E. Wheatley, III
    • Charles E. Wheatley, III
    • H04B1/04H04B7/005H04B7/26H04L27/30H04J13/02
    • H04W52/226H04W52/225H04W52/54
    • A link quality improvement system for a cellular communication system in which portable units are used to facilitate communication of information signals between system users, via at least one cell-site, using code division multiple access spread spectrum communication signals. The system enables users to improve the quality of reverse communication links from the portable units to the cell-site by providing to each system user a link quality signal indicative of power received at the cell-site relative to an optimum level of received power. At a cell-site communicating with a portable unit associated with a particular system user, the portable unit transmitted power is measured as received at the cell-site. A command signal is generated at the cell-site and transmitted to the portable unit for adjusting portable unit transmitter power. The command signals are also accumulated in order to enable generation of a link quality signal in response thereto. In a preferred implementation the link quality signal is an audible interference signal inducing the system user to adjust orientation of the portable communication unit so as to improve signal quality on the reverse link.
    • 一种用于蜂窝通信系统的链路质量改进系统,其中使用便携式单元来通过至少一个小区站点使用码分多址扩展频谱通信信号促进系统用户之间的信息信号的通信。 该系统使用户能够通过向每个系统用户提供指示在小区站点处相对于接收功率的最佳等级接收的功率的链路质量信号来提高从便携式设备到小区站点的反向通信链路的质量。 在与与特定系统用户相关联的便携式单元进行通信的小区站点处,便携式单元发射功率是在小区现场接收的。 在小区站点生成指令信号并发送到便携式单元,用于调节便携式单元发射机功率。 还累积了命令信号,以便响应于此产生链路质量信号。 在优选实施例中,链路质量信号是可听干扰信号,引起系统用户调整便携式通信单元的方位,从而提高反向链路上的信号质量。
    • 89. 发明授权
    • Precoding of signature sequences for CDMA systems
    • CDMA系统的签名序列的预编码
    • US5461610A
    • 1995-10-24
    • US938072
    • 1992-08-31
    • Vijitha Weerackody
    • Vijitha Weerackody
    • H04Q7/38H04B7/26H04L27/30
    • H04J11/0036H04B7/2628H04J13/10
    • A technique for reducing multiple access interference (MAI) experienced by receivers of transmissions from a transmitter, e.g., a base station, in a direct-sequence code division multiple access communication system, e.g., a cellular radio system, is disclosed. The technique provides for the precoding of user signature sequences for use in spreading information signals to be transmitted. The use of precoded signature sequences significantly reduces the average level of MAI experienced by the receivers. Despreading of received signals by receivers may be accomplished with the original (i.e., non-precoded) signature sequences. Thus, no changes to receivers are required. The technique includes a feature for determining a set of sequences for both transmitter and receiver from a smaller set of orthogonal sequences.
    • 公开了用于减少来自发射机(例如基站)的传输的接收机经历的直接序列码分多址通信系统(例如蜂窝无线电系统)中经历的多址接入干扰(MAI)的技术。 该技术提供用于在要发送的信息信号的扩展中使用的用户签名序列的预编码。 使用预编码签名序列显着降低了接收机经历的MAI的平均水平。 接收机对接收到的信号的去扩展可以用原始(即非预编码的)签名序列完成。 因此,不需要更改接收器。 该技术包括用于从较小的正交序列组确定发射机和接收机的一组序列的特征。
    • 90. 发明授权
    • DTMF signal receiving circuit
    • DTMF信号接收电路
    • US5459785A
    • 1995-10-17
    • US098907
    • 1993-07-29
    • Mitsuhiko Noda
    • Mitsuhiko Noda
    • H04L27/30H04Q1/453H04Q1/46H04M11/08
    • H04Q1/46H04L27/30H04Q1/453
    • A DTMF signal receiving circuit which is capable of freely selecting a frequency of a received dial tone signal. The DTMF signal receiving circuit receives a DTMF signal, decodes the DTMF signal, and outputs the signal as the decoding result. The DTMF signal receiving circuit comprises a dial tone signal detecting circuit for freely selecting a frequency of a dial tone signal which is the object of detection in accordance with a supplied selection signal, and a judging circuit for judging whether or not the signal as the result of detection of the DTMF signal is output on the basis of the output of the dial tone signal detecting circuit.
    • 一种DTMF信号接收电路,其能够自由选择所接收的拨号音信号的频率。 DTMF信号接收电路接收DTMF信号,对DTMF信号进行解码,并输出该信号作为解码结果。 DTMF信号接收电路包括拨号音信号检测电路,用于根据所提供的选择信号自由选择作为检测对象的拨号音信号的频率,以及用于判断作为结果的信号的判断电路 基于拨号音信号检测电路的输出输出DTMF信号的检测。