公开(公告)号：US06795423B1

公开(公告)日：2004-09-21

申请号：US09497413

申请日：2000-02-04

Applicant: Nadir Sezgin ,  Stephen G. Dick

Inventor： Nadir Sezgin ,  Stephen G. Dick

IPC: H04J1304

CPC classification number: H04B1/71 ,  H04B1/7115

Abstract: A method is disclosed for receiving transmitted signals in the presence of CW interference in a communication system that determines the presence of a code in a received signal by comparing with a detector threshold calculations made in accordance with a sample of a received signal. Such systems include but are not limited to those incorporating a Sequential Probability Ratio Test. The method includes obtaining a first input power value of the received signal at a first sample time and obtaining a second input power value of the received signal at a second sample time. The first and second power values are compared in order to provide an input sample comparison and the forgoing steps are repeated in order to provide a plurality of input sample comparisons. The detector threshold is adjusted in accordance with the plurality of sample comparisons. The CW signal can be strongly correlated with a short code used for the acquisition purposes. Therefore in the CDMA systems if the received signal contains a CW signal, then the strong correlation between the CW signal and the short code used for acquisition may result in a false alarm. To prevent this, the following algorithm is suggested to be used for the cancellation of CW, if there is a CW signal present in the received CDMA signal.

Abstract translation: 公开了一种用于在存在CW干扰的情况下在通信系统中接收发送信号的方法，该通信系统通过与根据接收信号的样本进行的检测器阈值计算进行比较来确定接收信号中的代码的存在。 这样的系统包括但不限于那些并入连续概率比测试。 该方法包括在第一采样时间获得接收信号的第一输入功率值，并在第二采样时间获得接收信号的第二输入功率值。 比较第一和第二功率值以提供输入样本比较，并且重复前述步骤以提供多个输入样本比较。 根据多个样本比较来调整检测器阈值.CCR信号可以与用于获取目的的短代码强相关。 因此，在CDMA系统中，如果接收到的信号包含CW信号，则CW信号与用于采集的短码之间的强相关可能导致虚警。 为了防止这种情况，如果在接收的CDMA信号中存在CW信号，则建议将以下算法用于CW的消除。

公开(公告)号：US06532250B1

公开(公告)日：2003-03-11

申请号：US09468111

申请日：1999-12-21

Applicant: Torgny Palenius ,  Martin Jonsson

Inventor： Torgny Palenius ,  Martin Jonsson

IPC: H04J1304

CPC classification number: H04B1/707 ,  H04B2201/70705

Abstract: Code Division Multiple Access (CDMA) spreading and despreading techniques eliminate the need for frame-length chip buffers within despreading and demodulation processors in CDMA receivers. According to the invention, successive CDMA frames are transmitted with variable spreading factors and a constant spreading sequence chip rate to provide a variable data throughput rate, each transmitted frame thus including a variable number of data symbols and a variable number of rate indication symbols. During transmission, channelization spreading sequences used for higher data rate frames are guaranteed to be subsets of channelization spreading sequences used for lower data rate frames. Consequently, a CDMA despreading processor according to the invention can despread incoming data symbols as they arrive at a CDMA receiver, storing the resulting symbols to a memory which must exist irrespective of the despreading process (e.g., within a deinterleaver or error detection and correction decoder). For example, incoming chips can be despread using a minimum allowable spreading rate and, upon receiving the rate information symbols included in the incoming frame, a determination can be made as to whether despreading is complete. If it is determined that the frame was spread using the minimum allowable spreading factor, then the stored data symbols are accepted as finally despread data symbols and further reception processing continues directly. Otherwise, the stored data symbols are taken to be temporary symbols which are then combined, using the guaranteed relationships between fast and slow spreading sequences, to generate the finally despread data symbols. Advantageously, a CDMA receiver according to the invention can thus operate successfully without requiring a frame-length despreading chip buffer.

Abstract translation: 码分多址（CDMA）扩展和解扩技术消除了在CDMA接收机中解扩和解调处理器内的帧长度芯片缓冲器的需要。 根据本发明，连续的CDMA帧以可变的扩频因子和恒定的扩展序列码片速率被发送，以提供可变的数据吞吐速率，每个发送的帧因此包括可变数量的数据符号和可变数量的速率指示符号。 在传输期间，用于较高数据速率帧的信道化扩展序列被确保为用于较低数据速率帧的信道化扩展序列的子集。 因此，根据本发明的CDMA解扩处理器可以在输入的数据符号到达CDMA接收机时解扩输入数据符号，将得到的符号存储到必须存在的存储器中，而与解扩处理无关（例如，在解交织器或错误检测和校正解码器 ）。 例如，输入芯片可以使用最小允许扩展速率进行解扩，并且在接收到包括在输入帧中的速率信息符号时，可以确定解扩是否完成。 如果确定使用最小允许扩展因子来扩展帧，则存储的数据符号被接受为最终解扩数据符号，并且进一步的接收处理继续进行。 否则，将所存储的数据符号取为临时符号，然后使用快速和慢速扩展序列之间的保证关系组合，以生成最终解扩数据符号。 有利地，根据本发明的CDMA接收机因此可以成功地操作，而不需要帧长度解扩芯片缓冲器。

公开(公告)号：US06282233B1

公开(公告)日：2001-08-28

申请号：US09287563

申请日：1999-04-06

Applicant: Shousei Yoshida

Inventor： Shousei Yoshida

IPC: H04J1304

CPC classification number: H04B1/71075

Abstract: A multi-user receiving apparatus for inputting a CDMA reception signal, performing an interference canceling process in parallel for each user signal on an m-th stage of M stages (where m is any integer of 1≦m≦M; and M is any integer of M ≧2), and outputting demodulated signals on the M-th stage is disclosed, that comprises a plurality of IEUs (interference estimating units) disposed corresponding to the (M−1) stages and the number of user signals, and a plurality of subtracting units disposed corresponding to the (M−1) stages, wherein each of the IEUs Inputs an interference cancellation residual signal obtained in an (m−1)-th stage interference canceling process and a signal of which a symbol replica corresponding to the same user signal on the (m−1)-th stage is weighted with a first weighting coefficient, generates an m-th stage symbol replica, outputs the m-th stage symbol replica to the (m+1)-th stage, and outputs a spread signal that is the difference between the m-th stage symbol replica and the (m−1)-th stage symbol replica weighted with the first weighting coefficient, and wherein each of the subtracting units subtracts signals of which the spread signals that are output from the IEUs on the m-th stage are weighted with a second weighting coefficient from a signal of which the (m−1)-th stage interference cancellation residual signal is delayed by a predetermined value and outputs the resultant signal to the (m+1)-th stage.

Abstract translation: 一种用于输入CDMA接收信号的多用户接收装置，在M级的第m级（其中m是1 <= m <= M的任何整数）中对每个用户信号并行执行干扰消除处理;并且M 是M> = 2的任何整数），并且在第M级上输出解调信号，其包括对应于（M-1）级和用户信号数量设置的多个IEU（干扰估计单元） 以及对应于（M-1）级设置的多个减法单元，其中每个IEU输入在第（m-1）级干扰消除处理中获得的干扰消除残差信号和其中符号 将与第（m-1）级相同的用户信号的副本用第一加权系数加权，生成第m级符号副本，将第m级符号副本输出到第（m + 1） - 并输出作为第m级sym之差的扩展信号 以及第一加权系数加权的第（m-1）级符号副本，并且其中每个减法单元减去从第m级的IEU输出的扩展信号被加权的信号， 从第（m-1）级干扰消除残差信号的信号延迟预定值的第二加权系数，并将所得到的信号输出到第（m + 1）级。

公开(公告)号：US06266363B1

公开(公告)日：2001-07-24

申请号：US09522034

申请日：2000-03-08

Applicant: Katsuhiko Hiramatsu

Inventor： Katsuhiko Hiramatsu

IPC: H04J1304

CPC classification number: H04J13/16 ,  H04J13/0077 ,  H04L1/0002 ,  H04L1/0003 ,  H04L1/0025 ,  H04L1/18 ,  H04L1/206 ,  H04L2001/0096

Abstract: Transmitting/receiving apparatuses are installed in a base station and a mobile station, respectively, to perform mutual transmission and reception by using a plurality of spreading codes. The transmitting/receiving apparatus installed in the base station has a block for designating to the mobile station the kind and the number of spreading codes used in a reverse link from the mobile station to the base station through a forward link at the time that communication with the mobile station is started. The transmitting/receiving apparatus installed in the mobile station has a block for transmitting a signal to the base station by using spreading codes of the designated kind and number. The transmitting/receiving apparatus installed in the base station further has a block for detecting receiving quality values of the signal transmitted from the mobile station with respect to individual spreading codes used in the mobile station, a block for deciding whether or not the detected receiving quality values exceed a prescribed quality value, and a block for finally setting the kind and number of spreading codes to be used in the reverse link on the basis of the spreading codes for which the detected receiving quality values are determined to exceed the prescribed quality value.

Abstract translation: 发送/接收装置分别安装在基站和移动台中，以通过使用多个扩展码进行相互发送和接收。 安装在基站中的发送/接收装置具有用于向移动台指定在与来自移动台到基站的反向链路中通过前向链路使用的扩展码的种类和数量的块， 移动台启动。 安装在移动站中的发送/接收装置具有通过使用指定种类和数量的扩展码向基站发送信号的块。 安装在基站中的发送/接收装置还具有用于检测从移动站发送的信号的接收质量的块，用于相对于在移动站中使用的各个扩展码的接收质量值，用于判定检测到的接收质量 值超过规定质量值，以及用于根据检测到的接收质量值被确定为超过规定质量值的扩展码，最终设定在反向链路中使用的扩展码的种类和数量的块。

公开(公告)号：US06735241B1

公开(公告)日：2004-05-11

申请号：US09609647

申请日：2000-07-03

Applicant: Roi Fujita

Inventor： Roi Fujita

IPC: H04J1304

CPC classification number: H04B1/707 ,  H04B2201/70701

Abstract: In a CDMA receiver of the present invention in accordance with the IS-95 standard, at least one pilot filter is provided externally of a loop for synchronization tracking. Then filtering processing of a pilot signal and synchronization tracking processing is performed concurrently. Further using synchronization establishment information transmitted from a base station, a rate for the synchronization tracking is adaptively changed. Furthermore a time constant of the pilot filter independently provided is set using information from an AFC circuit. According to the present invention, it is possible to perform the filtering processing of the pilot signal assuredly, and to improve the synchronization tracking capability.

Abstract translation: 在根据IS-95标准的本发明的CDMA接收机中，在用于同步跟踪的循环外部提供至少一个导频滤波器。 然后同时执行导频信号的滤波处理和同步跟踪处理。 进一步使用从基站发送的同步建立信息，自适应地改变用于同步跟踪的速率。 此外，使用来自AFC电路的信息来设置独立提供的导频滤波器的时间常数。 根据本发明，能够可靠地进行导频信号的滤波处理，提高同步跟踪能力。

公开(公告)号：US06549565B1

公开(公告)日：2003-04-15

申请号：US09455947

申请日：1999-12-07

Applicant: R. Michael Buehrer ,  Shang-Chieh Liu

Inventor： R. Michael Buehrer ,  Shang-Chieh Liu

IPC: H04J1304

CPC classification number: H04B1/7075 ,  H04B1/7105 ,  H04B1/71052 ,  H04B1/7115 ,  H04B2201/70707

Abstract: A Code Division Multiple Access system and method of operation provides reduced interference for received signals and improved signal acquisition and processing with reduced computational complexity. The system includes a base station coupled to an antenna array of at least two or more antennas and serving a plurality of users. A receiver in the base station includes a universal inverse cross-correlation matrix coupled to the antenna array, a signal acquisition and a signal processing circuit serving each user. Each signal acquisition circuit comprises a series of delay stages in which the incoming antenna signals in each stage are correlated with a spreading code and combined in a multiplier coupled to the universal inverse cross-correlation matrix which facilitates improved time delay estimation for signal acquisition. Each multiplier combines the correlated signals of the stage with the output of the universal inverse cross-correlation matrix to provide a signal amplitude representative of the signal energy in an antenna path for a given time period, with individual delays separated by a half of chip period. The amplitudes for each of the delay stages are captured in buffers which contain threshold information for selection of the strongest received signal. The signal processing circuit combines the strongest received signal with a channel estimate and the universal inverse matrix output in a multiplier to provide an output signal for demodulation and decoding with improved signal quality due to (a) reduced interference, (b) improved synchronization for signal acquisition and processing, and (c) the universal inverse cross-correlation matrix reducing computational complexity in signal acquisition and signal processing.

Abstract translation: 码分多址系统和操作方法提供了减少的接收信号干扰，并改进了信号采集和处理，降低了计算复杂度。 该系统包括耦合到至少两个或更多个天线的天线阵列并为多个用户服务的基站。 基站中的接收机包括耦合到天线阵列的通用逆互相关矩阵，信号采集和为每个用户服务的信号处理电路。 每个信号采集电路包括一系列延迟级，其中每级中的输入天线信号与扩展码相关，并且组合在耦合到通用逆互相关矩阵的乘法器中，这有助于改进用于信号采集的时间延迟估计。 每个乘法器将该阶段的相关信号与通用逆互相关矩阵的输出相结合，以提供表示给定时间段内的天线路径中的信号能量的信号幅度，其中各个延迟与码片周期的一半相隔 。 每个延迟级的幅度被捕获在包含用于选择最强接收信号的阈值信息的缓冲器中。 信号处理电路将最强的接收信号与信道估计和乘法器中的通用逆矩阵输出相结合，以提供用于解调和解码的输出信号，由于（a）减少的干扰，（b）提高信号的同步，改善了信号质量 采集和处理，以及（c）通用逆互相关矩阵降低信号采集和信号处理中的计算复杂度。

公开(公告)号：US06389060B1

公开(公告)日：2002-05-14

申请号：US08989646

申请日：1997-12-12

Applicant: Tetsuya Naruse

Inventor： Tetsuya Naruse

IPC: H04J1304

CPC classification number: H04B1/712 ,  H04B1/7115

Abstract: A CDMA receiver in which a searcher searches paths, fingers de-spread received signals and demodulate data for the searched paths, and a combiner combines output data of the fingers according to levels of the received signals. Furthermore, gain amplifiers that designate weights for respective paths are included in the combiner and signal intensities of demodulated data through the respective paths are detected. The gain amplifiers designate weights for the respective paths in such a manner that larger weights are designated to paths with larger signal intensities.

Abstract translation: 一种CDMA接收机，其中搜索器搜索路径，手指解扩接收信号并解调所搜索路径的数据，并且组合器根据接收信号的电平组合手指的输出数据。 此外，指定相应路径的权重的增益放大器包括在组合器中，并且检测通过相应路径的解调数据的信号强度。 增益放大器以这样的方式指定相应路径的权重，即较大权重被指定为具有较大信号强度的路径。

公开(公告)号：US06282231B1

公开(公告)日：2001-08-28

申请号：US09461123

申请日：1999-12-14

Applicant: Charles P. Norman ,  Charles R. Cahn

Inventor： Charles P. Norman ,  Charles R. Cahn

IPC: H04J1304

CPC classification number: H04B1/7107 ,  G01S19/21 ,  G01S19/246 ,  G01S19/30

Abstract: A CDMA coded, spread spectrum radio signal containing a strong signal and a weak signal is received, and the interference of the strong signal with the weak signal is computed to enhance the ability to track the weak signal. The codes modulating both signals are known, and the weak signal can be predicted. The interference of the strong signal is calculated as the product of the amplitude of the strong signal and the predicted crosscorrelation of the strong signal with the weak signal. The strong signal may be measured, predicted, or acquired through a combination of both methods. The crosscorrelation may be predicted for a range of weak signal values, and the weak signal selected as the prediction producing the greatest received power.

Abstract translation: 接收包含强信号和弱信号的CDMA编码的扩频无线电信号，并计算强信号与弱信号的干扰，以增强跟踪弱信号的能力。 调制两个信号的码是已知的，并且可以预测弱信号。 强信号的干扰被计算为强信号的幅度与强信号与弱信号的预测交叉相关的乘积。 可以通过两种方法的组合来测量，预测或获取强信号。 可以针对弱信号值的范围预测互相关，并且选择作为产生最大接收功率的预测的弱信号。

公开(公告)号：US06816543B1

公开(公告)日：2004-11-09

申请号：US09654730

申请日：2000-09-05

Applicant: Akira Shibuta

Inventor： Akira Shibuta

IPC: H04J1304

CPC classification number: H04B1/7077

Abstract: A spread spectrum communications apparatus for synchronizing a received spread spectrum modulated signal and a de-spreading code, and its synchronization acquisition method are disclosed. In the first synchronization acquisition operation, the phase of the de-spreading code is sequentially changed finely depending on the number of chips, and the correlation value of the spread spectrum modulated signal and de-spreading code is detected. Further, the maximum value and average of the correlation value for the number of times of detection are determined. When the maximum value is judged to be larger than the sum of the average and a specified threshold level, the first acquisition operation is completed. Consequently, the process is advanced to a second synchronization acquisition operation for determining the phase for establishing the synchronization by changing finely the phase of the de-spreading code before and after the phase corresponding to the maximum value.

公开(公告)号：US06452961B1

公开(公告)日：2002-09-17

申请号：US09659647

申请日：2000-09-12

Applicant: Robert J. Van Wechel

Inventor： Robert J. Van Wechel

IPC: H04J1304

CPC classification number: H04B1/708 ,  G01S19/29 ,  G01S19/30 ,  G01S19/37 ,  H04B1/70735 ,  H04B1/70755 ,  H04B2201/70707

Abstract: An apparatus and method allow receivers to quickly acquire a pseudorandom noise signal. A receiver advantageously detects frequency shifts using a compact parallel process hardware implementation of a Discrete Fourier Transform (DFT). The method applies a sequential test algorithm to the detection of a correlation signal. The method allows the receiver to search a range of frequency-time space relatively quickly.

Abstract translation: 一种装置和方法允许接收机快速获取伪随机噪声信号。 接收机有利地使用离散傅立叶变换（DFT）的紧凑并行处理硬件实现来检测频移。 该方法将连续测试算法应用于检测相关信号。 该方法允许接收机相对快速地搜索频率 - 时间空间的范围。