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    Method and apparatus for detecting zero rate frames in a communications system
    143.
    发明授权
    Method and apparatus for detecting zero rate frames in a communications system 有权
    用于在通信系统中检测零速率帧的方法和装置

    公开(公告)号：US06356601B1

    公开(公告)日：2002-03-12

    申请号：US09725351

    申请日：2000-11-29

    Applicant: Tao Chen ,  Shimman Patel

    Inventor： Tao Chen ,  Shimman Patel

    IPC: H04L2706

    CPC classification number: H04L1/208 ,  H03M13/3738 ,  H04B2201/70705 ,  H04L1/20 ,  H04W52/26

    Abstract: Techniques for detecting zero rate frames in a received data transmission. A modulated signal is received and demodulated in accordance with a particular demodulation format to generate demodulated symbols. The demodulated symbols are partitioned into a number of received frames. For each received frame, a quality metric is computed and compared against a threshold value. The threshold value is selected based, in part, on the quality metrics of received frames. Based on the comparison result, the received frame is indicated as being either transmitted and received in error (i.e., erased or bad) or not transmitted at all (i.e., zero rate or empty). The quality metric can relate to an energy of a received frame, a distance between a received frame and a codeword corresponding to the received frame, or other metrics. The threshold value can be selected based on the quality metrics computed for decoded frames or received frames identified as good, and can be dynamically adjusted based on current information available at the receiver. The method is advantageously used in a CDMA communications system.

    Abstract translation: 在接收数据传输中检测零速率帧的技术。 根据特定解调格式接收和解调调制信号以产生解调符号。 解调的符号被分割成多个接收的帧。 对于每个接收的帧，计算质量度量并将其与阈值进行比较。 部分地基于接收帧的质量度量来选择阈值。 基于比较结果，接收到的帧被指示为发送和接收错误（即，擦除或不良）或完全没有发送（即，零率或空）。 质量度量可以涉及接收帧的能量，接收到的帧与对应于接收到的帧的码字之间的距离或其他度量。 可以基于为被识别为良好的解码帧或接收帧计算的质量度量来选择阈值，并且可以基于接收器处可用的当前信息来动态地调整阈值。 该方法有利地用于CDMA通信系统中。

    Rate adjustment technique in a CDMA receiver
    144.
    发明申请
    Rate adjustment technique in a CDMA receiver 审中-公开
    CDMA接收机中的速率调整技术

    公开(公告)号：US20020003834A1

    公开(公告)日：2002-01-10

    申请号：US09866556

    申请日：2001-05-25

    Applicant: NEC CORPORATION.

    Inventor： Shinjiro Yoshimura

    IPC: H04K001/00 ,  H04B015/00 ,  H04B007/216 ,  H04L027/30

    CPC classification number: H04L1/208 ,  H04B1/707 ,  H04B7/264 ,  H04B2201/70705 ,  H04L1/20 ,  H04L25/0262

    Abstract: A rate adjustment device allowing the burden on a decoder to be reduced when decoding a variable-rate channel is disclosed. After despreadirg a received baseband signal based on a predetermined symbol rate to produce rate-indicating data and a sequence of received correlation values, a received symbol rate is compared to the maximum symbol rate and, when the received symbol rate is lower than the maximum symbol rate, it is determined whether a receive quality is satisfactory. When the receive quality is satisfactory, at least one received correlation value is selected from the received correlation values and is used to generate a correlation value matching the received symbol rate.

    Abstract translation: 公开了一种在对可变速率信道进行解码时能够减小解码器负担的速率调整装置。 在基于预定符号速率解扩接收基带信号以产生速率指示数据和接收到的相关值序列之后，将接收到的符号速率与最大符号速率进行比较，并且当接收到的符号速率低于最大符号 率，确定接收质量是否令人满意。 当接收质量满意时，从接收到的相关值中选择至少一个接收到的相关值，并且用于产生与接收到的符号速率匹配的相关值。

    Method and apparatus for detecting zero rate frames in a communications system
    145.
    发明申请
    Method and apparatus for detecting zero rate frames in a communications system 有权

    公开(公告)号：US20010000221A1

    公开(公告)日：2001-04-12

    申请号：US09725351

    申请日：2000-11-29

    Inventor： Tao Chen ,  Shimman Patel

    IPC: H03D001/00

    CPC classification number: H04L1/208 ,  H03M13/3738 ,  H04B2201/70705 ,  H04L1/20 ,  H04W52/26

    Abstract: Techniques for detecting zero rate frames in a received data transmission. A modulated signal is received and demodulated in accordance with a particular demodulation format to generate demodulated symbols. The demodulated symbols are partitioned into a number of received frames. For each received frame, a quality metric is computed and compared against a threshold value. The threshold value is selected based, in part, on the quality metrics of received frames. Based on the comparison result, the received frame is indicated as being either transmitted and received in error (i.e., erased or bad) or not transmitted at all (i.e., zero rate or empty). The quality metric can relate to an energy of a received frame, a distance between a received frame and a codeword corresponding to the received frame, or other metrics. The threshold value can be selected based on the quality metrics computed for decoded frames or received frames identified as good, and can be dynamically adjusted based on current information available at the receiver. The method is advantageously used in a CDMA communications system.

    Method and apparatus for detecting zero rate frames in a communications system
    146.
    发明授权
    Method and apparatus for detecting zero rate frames in a communications system 有权
    用于在通信系统中检测零速率帧的方法和装置

    公开(公告)号：US06208699B1

    公开(公告)日：2001-03-27

    申请号：US09388029

    申请日：1999-09-01

    Applicant: Tao Chen ,  Shimman Patel

    Inventor： Tao Chen ,  Shimman Patel

    IPC: H04L2706

    CPC classification number: H04L1/208 ,  H03M13/3738 ,  H04B2201/70705 ,  H04L1/20 ,  H04W52/26

    Abstract: Techniques for detecting zero rate frames in a received data transmission. A modulated signal is received and demodulated in accordance with a particular demodulation format to generate demodulated symbols. The demodulated symbols are partitioned into a number of received frames. For each received frame, a quality metric is computed and compared against a threshold value. The threshold value is selected based, in part, on the quality metrics of received frames. Based on the comparison result, the received frame is indicated as being either transmitted and received in error (i.e., erased or bad) or not transmitted at all (i.e., zero rate or empty). The quality metric can relate to an energy of a received frame, a distance between a received frame and a codeword corresponding to the received frame, or other metrics. The threshold value can be selected based on the quality metrics computed for decoded frames or received frames identified as good, and can be dynamically adjusted based on current information available at the receiver. The method is advantageously used in a CDMA communications system.

    Abstract translation: 在接收数据传输中检测零速率帧的技术。 根据特定解调格式接收和解调调制信号以产生解调符号。 解调的符号被分割成多个接收的帧。 对于每个接收的帧，计算质量度量并将其与阈值进行比较。 部分地基于接收帧的质量度量来选择阈值。 基于比较结果，接收到的帧被指示为发送和接收错误（即，擦除或不良）或完全没有发送（即，零率或空）。 质量度量可以涉及接收帧的能量，接收到的帧与对应于接收到的帧的码字之间的距离或其他度量。 可以基于为被识别为良好的解码帧或接收帧计算的质量度量来选择阈值，并且可以基于接收器处可用的当前信息来动态地调整阈值。 该方法有利地用于CDMA通信系统中。

    Apparatus and method for estimating a variable data rate
    147.
    发明授权
    Apparatus and method for estimating a variable data rate 失效
    用于估计可变数据速率的装置和方法

    公开(公告)号：US5978428A

    公开(公告)日：1999-11-02

    申请号：US701481

    申请日：1996-08-22

    Applicant: Hiroshi Hayashi

    Inventor： Hiroshi Hayashi

    IPC: H04B1/707 ,  H04B7/26 ,  H04L25/02 ,  H04B1/66 ,  H04L27/06

    CPC classification number: H04L25/0262 ,  H04B7/264 ,  H04B2201/70705

    Abstract: A digital communication system is disclosed. A transmitter combines a digitized signal into a digital data stream with variable data rate and transmits it to a receiver. The receiver decodes the received signal with an actually transmitted data rate. For this reason, the receiver has to estimate the coding data rate of the received signal. The receiver decodes the received signal at one decoding rate, which is evaluated whether the decoding rate is correct or not. Such evaluation is achieved by, for example, measuring S/N ratio. According to such estimation the receiver estimates the actual transmitted data rate.

    Abstract translation: 公开了一种数字通信系统。 发射机将数字化信号组合成具有可变数据速率的数字数据流，并将其发送到接收机。 接收机以实际发送的数据速率对接收到的信号进行解码。 为此，接收机必须估计接收信号的编码数据速率。 接收机以一个解码速率解码接收信号，评估解码速率是否正确。 这样的评估通过例如测量S / N比来实现。 根据这样的估计，接收机估计实际发送的数据速率。

    Methods and apparatus for performing rate determination with a variable rate viterbi decoder
    148.
    发明授权
    Methods and apparatus for performing rate determination with a variable rate viterbi decoder 失效
    用可变速率维特比解码器进行速率确定的方法和装置

    公开(公告)号：US5796757A

    公开(公告)日：1998-08-18

    申请号：US529101

    申请日：1995-09-15

    Applicant: Stash Czaja

    Inventor： Stash Czaja

    IPC: H04B1/707 ,  H04L1/00 ,  H04L1/08 ,  H04L25/02 ,  H03M13/12

    CPC classification number: H04L1/0057 ,  H04B1/707 ,  H04L1/0046 ,  H04L1/0054 ,  H04L1/08 ,  H04L1/208 ,  H04L25/0262 ,  H04B2201/70705

    Abstract: A method in accordance with this invention includes the steps of (a) decoding a received signal and determining, for individual ones of n data rates, a value of a total cumulative metric associated with a most likely path through a decoder trellis; (b) comparing the value of the total cumulative metric to a plurality of total cumulative metric threshold values, individual ones of the plurality of total cumulative metric threshold values corresponding to an expected total cumulative metric for an individual one of the n data rates and being one of fixed or adaptively determined; and (c) identifying the received data rate based on the comparison. The step of determining a total cumulative metric includes the steps of (a) processing branch metrics to determine survivor metrics; (b) normalizing individual ones of the survivor metrics to form normalized survivor metrics; (c) accumulating the normalized survivor metrics to form cumulative metrics; (d) accumulating normalization values used to normalize each of the normalized survivor metrics; (e) at the end of decoding, outputting a cumulative metric that corresponds to a most likely path through the trellis; and (f) combining an accumulated normalization value with the outputted cumulative metric to form the total cumulative metric.

    Abstract translation: 根据本发明的方法包括以下步骤：（a）对接收到的信号进行解码，并且针对n个数据速率中的各个数据速率确定与通过解码器格架的最可能的路径相关联的总累积度量的值; （b）将总累积度量的值与多个总累积度量阈值进行比较，所述多个总累积度量阈值中的各个总累积度量阈值对应于n个数据速率中的一个的预期总累积度量，并且为 一个固定或自适应确定; 和（c）基于比较来识别所接收的数据速率。 确定总累积度量的步骤包括以下步骤：（a）处理分支度量以确定幸存度量; （b）使个体幸存者度量标准化，以形成归一化幸存者指标; （c）积累归一化幸存者度量以形成累积度量; （d）累积用于归一化归一化幸存者度量标准化的归一化值; （e）在解码结束时，输出对应于通过网格的最可能路径的累积度量; 和（f）将累积归一化值与所输出的累积度量进行组合以形成总累积度量。

    Subsequent frame variable data rate indication method
    149.
    发明授权
    Subsequent frame variable data rate indication method 失效
    后续帧可变数据速率指示方法

    公开(公告)号：US5537410A

    公开(公告)日：1996-07-16

    申请号：US306777

    申请日：1994-09-15

    Applicant: Kaiping Li

    Inventor： Kaiping Li

    IPC: H04B1/707 ,  H04L1/00 ,  H04L1/08 ,  H04T3/22

    CPC classification number: H04L1/0028 ,  H04B1/707 ,  H04L1/0014 ,  H04L1/0039 ,  H04L1/08 ,  H04B2201/70705 ,  H04L1/0025 ,  H04L1/0046

    Abstract: In a synchronous fixed frame boundary system with variable data rates, a transmitter inserts into a current frame an indication of the data rate of the next frame. After the first frame is received and processed at a receiver, the data rates of subsequent frames are known before processing, thereby reducing processing load. Furthermore, because the rate indication is inserted into the frame to be error protected along with the rest of the frame information, reliability is high, while additional data overhead and complexity are very low. As an example, North American code division multiple access digital cellular telephone systems utilize variable data rate transmissions. As a station modem (SM) assembles a current frame for convolutional encoding and further processing, the SM inserts a rate indication for the subsequent frame in accordance with information from a vocoder and CPU of the appropriate data rate for the subsequent frame. On the receiving end, rather than needing to decode multiple times to determine the appropriate data rate for every frame, the receiving SM discovers the rate of each frame subsequent to the first frame by analyzing the information contained in the immediately preceding frame. The rate determination process also includes a verification method based upon a frame quality indicator analysis and a symbol error rate analysis to ensure accurate data rate determination.

    Abstract translation: 在具有可变数据速率的同步固定帧边界系统中，发射机将当前帧插入到下一帧的数据速率的指示。 在接收器接收和处理第一帧之后，在处理之前已知后续帧的数据速率，从而减少处理负载。 此外，由于速率指示与帧信息的其余部分一起插入到帧中以被错误保护，所以可靠性高，而附加的数据开销和复杂度非常低。 例如，北美码分多址数字蜂窝电话系统利用可变数据速率传输。 由于站调制解调器（SM）组合用于卷积编码和进一步处理的当前帧，所以SM根据来自声码器和CPU的来自后续帧的适当数据速率的信息插入后续帧的速率指示。 在接收端，不需要多次解码以确定每帧的适当数据速率，接收SM通过分析紧接在前的帧中包含的信息来发现第一帧之后的每帧的速率。 速率确定过程还包括基于帧质量指示符分析和符号错误率分析的确认方法，以确保准确的数据速率确定。

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