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公开(公告)号：US06493322B1
公开(公告)日：2002-12-10
申请号：US08840268
申请日：1997-04-14
IPC分类号： H04J314
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。
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公开(公告)号：US5661724A
公开(公告)日：1997-08-26
申请号：US574141
申请日：1995-12-18
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。
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3.发明授权Trellis coding technique to increase adjacent channel interference protection ratio in land mobile radio systems under peak power constraints 失效网格编码技术在峰值功率约束下增加陆地移动无线电系统中的相邻信道干扰保护比
公开(公告)号：US5311553A
公开(公告)日：1994-05-10
申请号：US975201
申请日：1992-06-15
CPC分类号： H03M13/256 , H03M13/00 , H03M13/25 , H04L27/186
摘要： An optimum communication system employs an encoder coupled to a mapper and two parallel branches, each branch having a transmit filter a digital-to-analog converter, a low pass filter and a modulator coupled in series. Both modulators are coupled to a summer which provides an rf signal to a transmit antenna. A second antenna is coupled to a first down converter, an IF filter, a second down converter, an analog-to-digital converter and a decoder. The encoder is optimized by choosing a desired minimum Euclidean distance between symbols multiplied by the average to peak transmit power ratio (MPDR), an encoder alphabet and a number of constellation points. All possible encoder states and all possible input symbols are permutated to result in a plurality of encoder sets. The minimum distance between coded symbols and a P.sub.ib /P.sub.ab power ratio for each code set is determined. The encoder is adapted to output an encoder set U having a largest P.sub.ib /P.sub.ab power ratio having a large adjacent channel interference protection ratio. In an alternative embodiment, a minimum P.sub.ib /P.sub.ab power ratio (MPR) is chosen. The encoder is adapted to output an encoder set U having the largest minimum distance between coded symbols multiplied by the average to peak transmitted power ratio, that also has a P.sub.ib /P.sub.ab ratio that exceeds MPR.
摘要翻译： 最佳通信系统采用耦合到映射器和两个并行分支的编码器，每个分支具有发射滤波器，数模转换器，低通滤波器和串联耦合的调制器。 两个调制器耦合到向发射天线提供射频信号的夏季。 第二天线耦合到第一下变换器，IF滤波器，第二下变频器，模数转换器和解码器。 通过选择符号乘以平均与峰值发射功率比（MPDR），编码器字母和星座点数之间的期望的最小欧几里德距离来优化编码器。 所有可能的编码器状态和所有可能的输入符号被排列以产生多个编码器组。 确定每个代码集的编码符号与Pib / Pab功率比之间的最小距离。 编码器适于输出具有大的相邻信道干扰保护比的具有最大Pib / Pab功率比的编码器组U。 在替代实施例中，选择最小Pib / Pab功率比（MPR）。 编码器适于输出编码符号之间具有最大最小距离乘以平均值与峰值发射功率比的编码器组U，其也具有超过MPR的Pib / Pab比。
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公开(公告)号：US6046990A
公开(公告)日：2000-04-04
申请号：US559692
申请日：1995-11-15
CPC分类号： H04L1/08 , H04B7/18567 , H04W68/00 , H04W68/02 , H04W88/185
摘要： A method and system for increasing the signal margin of a radiocommunication link to provide a short message service which is reliable, even under non-ideal conditions. According to the method, an increase in transmission power is used in combination with bit repetition to increase signal margin without complications in the mobile unit design, significant delay, or co-channel interference. Where a more significant increase in signal margin is desired, when a longer message is required, or for voice messages, the message may be stored and the mobile unit alerted of the message.
摘要翻译： 一种用于增加无线电通信链路的信号余量以提供即使在非理想条件下也是可靠的短消息服务的方法和系统。 根据该方法，与比特重复结合使用传输功率的增加以增加信号容限，而不会在移动单元设计，显着的延迟或同信道干扰中出现并发症。 在需要更大幅度地增加信号余量的情况下，当需要更长的消息或者对于语音消息时，可以存储消息并且移动单元提醒消息。
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公开(公告)号：US5822310A
公开(公告)日：1998-10-13
申请号：US579015
申请日：1995-12-27
CPC分类号： H04L1/08 , H04B7/18567
摘要： A method and system for increasing the signal margin of a radiocommunication link to provide a short message service which is reliable, even under non-ideal conditions. According to the method, short alphanumeric messages can be transmitted over the broadcast control channel of a digital radiocommunication link, or another communication channel consisting of one or more slots from successive frames in a TDMA communication link. An increase in transmission power is used in combination with repetition to increase effective signal margin without complications in the mobile unit design, significant delay, or co-channel interference. Where a more significant increase in signal margin is desired, when a longer message is required, or for voice messages, the message may be stored and the mobile unit alerted of the message.
摘要翻译： 一种用于增加无线电通信链路的信号余量以提供即使在非理想条件下也是可靠的短消息服务的方法和系统。 根据该方法，可以通过数字无线电通信链路的广播控制信道或由TDMA通信链路中的连续帧的一个或多个时隙组成的另一通信信道来传送短的字母数字消息。 传输功率的增加与重复结合使用以增加有效信号容限，而不会在移动单元设计，显着的延迟或同信道干扰中出现并发症。 在需要更大幅度地增加信号余量的情况下，当需要更长的消息或者对于语音消息时，可以存储消息并且移动单元提醒消息。
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公开(公告)号：US06314081B1
公开(公告)日：2001-11-06
申请号：US08588507
申请日：1996-01-18
IPC分类号： H04J1100
CPC分类号： H04W4/14 , H04B7/18567
摘要： A communication system and method for transmitting relatively short data messages in the communication system. A dedicated frequency is sequentially switched into each of a plurality of satellite beams or traffic channels to transmit data messages at an increased power level to provide an increased signal margin. The increased power level of the dedicated frequency can be combined with coding and bit and message repetition to further increase the signal margin.
摘要翻译： 一种用于在通信系统中发送相对短的数据消息的通信系统和方法。 专用频率被顺序地切换到多个卫星波束或业务信道中的每一个以在增加的功率电平上发送数据消息以提供增加的信号余量。 专用频率的增加的功率电平可以与编码和比特和消息重复组合以进一步增加信号余量。
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7.发明授权公开(公告)号：US06192503B1
公开(公告)日：2001-02-20
申请号：US08911149
申请日：1997-08-14
IPC分类号： H03M1303
CPC分类号： H04L1/005 , H03M13/2975 , H04L1/0055 , H04L1/0066 , H04L1/007
摘要： A source sequence of symbols is communicated over a communications medium by encoding the source sequence according to respective first and second error correction codes to produce respective first and second encoded sequences of symbols. The first and second encoded sequences are processed to produce a communications signal, which is then communicated over the communications medium. The communicated communications signal is processed to produce first and second received sequences of symbols corresponding to the first and second encoded sequences, respectively. The first and second received sequences are selectively recursively decoded according to the associated error correction codes augmented by previous estimates of a symbol of the source sequence to repeatedly produce revised estimates of the symbol until an estimate satisfying a predetermined reliability criteria is obtained.
摘要翻译： 通过在源通信介质上通过根据相应的第一和第二纠错码对源序列进行编码来传送符号的源序列，以产生相应的第一和第二编码符号序列。 处理第一和第二编码序列以产生通信信号，然后通信信号在通信介质上传送。 所传送的通信信号被处理以分别产生对应于第一和第二编码序列的第一和第二接收的符号序列。 根据由源序列的符号的先前估计增加的相关联的纠错码来选择性地递归地解码第一和第二接收序列，以重复产生符号的修正估计，直到获得满足预定可靠性标准的估计。
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公开(公告)号：US5604806A
公开(公告)日：1997-02-18
申请号：US376144
申请日：1995-01-20
CPC分类号： H04L9/0838 , H04B17/24 , H04J13/00 , H04K1/00 , H04L2209/80
摘要： Characteristics of the radio channel are used to establish key sequences for use in encrypting communicated information. These characteristics are the short-term reciprocity and rapid spatial decorrelation of phase of the radio channel. The keys can be established with computations equivalent to a bounded distance decoding procedure, and the decoder used to establish a key may be used for processing the subsequent data transmission. Compared to classical and public-key systems, an alternative mechanism for establishing and sharing key sequences that depends on a physical process is provided in which each party need not generate a pseudorandom quantity because the necessary randomness is provided by the temporal and spatial non-stationarity of the communication channel itself. By using a channel decoder, the probability of two users establishing the same secret key is substantially unity, and the probability of an eavesdropper establishing the same key is substantially zero. Also, the number of possible keys is large enough that finding the correct one by exhaustive search is impractical.
摘要翻译： 无线电信道的特征用于建立用于加密通信信息的密钥序列。 这些特征是无线电信道相位的短期互惠和快速空间去相关。 可以通过与有界距离解码过程等效的计算来建立密钥，并且用于建立密钥的解码器可以用于处理随后的数据传输。 与古典和公钥系统相比，提供了一种用于建立和共享依赖于物理过程的密钥序列的替代机制，其中每个方不需要生成伪随机数，因为必要的随机性由时间和空间非平稳性 的通信信道本身。 通过使用信道解码器，建立相同密钥的两个用户的概率基本上是一致的，并且建立相同密钥的窃听者的概率基本为零。 此外，可能的键的数量足够大，通过穷举搜索找到正确的键是不切实际的。
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9.发明授权Trellis coding technique to improve adjacent channel interference protection ratio in land mobile radio systems 失效网格编码技术提高了陆地移动无线电系统中的相邻信道干扰保护比
公开(公告)号：US5311552A
公开(公告)日：1994-05-10
申请号：US898670
申请日：1992-06-15
CPC分类号： H04L27/186 , H03M13/25
摘要： An optimum communication system for communicating on adjacent frequency bands with minimal interference between adjacent channels comprises an encoder that is serially coupled to a mapper and two parallel processing branches, each processing branch having a transmit filter a digital-to-analog converter, a low pass filter and a modulator coupled in series. Both modulators are coupled to a summer, and an rf amplifier having a transmit antenna. The encoder is optimized by choosing a desired minimum Euclidean distance (DMED) between symbols, an encoder alphabet and a number of constellation points, permutating all possible encoder states and all possible input symbols to result in a plurality of encoder sets U, determining an in-band to adjacent band power ratio P.sub.ib /P.sub.ab for each code set is determined, discarding code sets U that having a minimum distance between symbol sets that do not exceed DMED, shifting by 90 degrees with respect to each other the phase of the signals passing through the modulators, and transmitting to a receiver the summation of the signals in each one of the parallel processing branches, whereby the encoder produces the code set of the remaining sets having the largest in-band to adjacent band power ratio P.sub.ib /P.sub.ab resulting in a transmitted signal having a spectrum that maximizes the ratio of in-band to adjacent band power for LMR systems. Maximizing the in-band to adjacent band power increases the ACIPR and also allows for increased data transmission rates.
摘要翻译： 用于在相邻频道之间以最小干扰在相邻频带上通信的最佳通信系统包括串行耦合到映射器和两个并行处理分支的编码器，每个处理分支具有发射滤波器，数模转换器，低通 滤波器和串联耦合的调制器。 两个调制器耦合到一个夏天，一个射频放大器具有发射天线。 编码器通过在符号，编码器字母表和多个星座点之间选择期望的最小欧几里德距离（DMED）来优化，排列所有可能的编码器状态和所有可能的输入符号，以产生多个编码器集合U， 确定每个代码集的带到相邻带功率比Pib / Pab，丢弃具有不超过DMED的符号集之间的最小距离的代码集合U，相对于彼此相对于信号通过的相位相移90度 通过调制器，并且向接收机发送每个并行处理分支中的信号的总和，由此编码器产生具有最大带内至相邻频带功率比Pib / Pab的剩余组的码集，导致 具有使LMR系统的带内相邻带功率的比率最大化的频谱的发射信号。 将带内最大化到相邻频带功率增加了ACIPR，并且还允许增加数据传输速率。
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10.发明授权High power short message service using TDMA frames and/or broadcast control channel 有权使用TDMA帧和/或广播控制信道的大功率短消息业务公开(公告)号：US06414945B1
公开(公告)日：2002-07-02
申请号：US09166793
申请日：1998-10-06
IPC分类号： H04B7212
摘要： A method and system for transmitting short data messages in a control station-based TDMA radiocommunication system. Selected TDMA frames are assigned as message frames, and one or more data slots from each message frame are assigned to transmitter/receivers. Data messages can be encoded and transmitted multiple times, at an increased power level, from a control station to a transmitter/receiver over the appropriate data slots in each message frame. The selected TDMA frames are preferably slow associated control channel frames. Also, short alphanumeric messages can be transmitted over the broadcast control channel of a digital radiocommunication link, or another communication channel consisting of one or more slots from successive frames in a TDMA communication link. An increase in transmission power is used in combination with repetition to increase effective signal margin without complications in the mobile unit design, significant delay, or co-channel interference. Where a more significant increase in signal margin is desired, when a longer message is required, or for voice messages, the message may be stored and the mobile unit alerted of the message.
摘要翻译： 一种用于在基于控制站的TDMA无线电通信系统中发送短数据消息的方法和系统。 所选TDMA帧被分配为消息帧，并且来自每个消息帧的一个或多个数据时隙被分配给发射机/接收机。 在每个消息帧中的数据消息可以通过适当的数据时隙从控制站到发射机/接收机以增加的功率电平被多次编码和传输。 选择的TDMA帧优选地是慢关联的控制信道帧。 此外，可以通过数字无线电通信链路的广播控制信道或由TDMA通信链路中的连续帧的一个或多个时隙组成的另一个通信信道来传送短的字母数字消息。 传输功率的增加与重复结合使用以增加有效信号容限，而不会在移动单元设计，显着的延迟或同信道干扰中出现并发症。 在需要更大幅度地增加信号余量的情况下，当需要更长的消息或者对于语音消息时，可以存储消息并且移动单元提醒消息。
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