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1. 发明授权

US5315589A TDMA synchronization using visibility designation 失效
标题翻译：使用可见性指定的TDMA同步
公开(公告)号：US5315589A
公开(公告)日：1994-05-24
申请号：US770206
申请日：1991-10-03
申请人： W. Robert Kepley , Stanley E. Kay , Ashim Roy , Steven M. Kee , Carle C. Henson, III , Adrian J. Morris , Randy Drago
发明人： W. Robert Kepley , Stanley E. Kay , Ashim Roy , Steven M. Kee , Carle C. Henson, III , Adrian J. Morris , Randy Drago
IPC分类号： H04B7/212 , H04Q11/04
CPC分类号： H04B7/2128
摘要： TDMA timing is maintained by the use of visibility information transmitted among the stations in a conference. Each station monitors the identity of stations from which bursts are received. A station also receives visibility information from other stations. The station combines the information to maintain a two-dimensional Visibility Designator Byte matrix or array. A station participates in the process by periodically transmitting its own VDB array to other stations. The stations then, independently, identify a prime station by using the collected and processed information. Using the same information, a station also identifies the manner in which it will lock to the timing of the prime station.
摘要翻译：通过使用在会议中的站之间发送的可见性信息来维持TDMA定时。每个站监视接收到脉冲串的站的身份。车站还从其他车站接收可见度信息。该站组合信息以维护二维可视性指示符字节矩阵或阵列。通过定期向其他站发送自己的VDB阵列，站参与该过程。然后，这些站独立地通过使用收集和处理的信息来识别主站。使用相同的信息，车站还会标识其锁定到主站的时间的方式。

2. 发明授权

US5459814A Voice activity detector for speech signals in variable background noise 失效
标题翻译：用于可变背景噪声的语音信号的语音活动检测器
公开(公告)号：US5459814A
公开(公告)日：1995-10-17
申请号：US38734
申请日：1993-03-26
申请人： Prabhat K. Gupta , Shrirang Jangi , Allan B. Lamkin , W. Robert Kepley, III , Adrian J. Morris
发明人： Prabhat K. Gupta , Shrirang Jangi , Allan B. Lamkin , W. Robert Kepley, III , Adrian J. Morris
IPC分类号： G10L25/09 , G10L25/78 , G10L9/00
CPC分类号： G10L25/78 , G10L2025/786 , G10L25/09
摘要： A voice activity detector (VAD) which determines whether an input signal contains speech by deriving parameters measuring short term time domain characteristics of the input signal, including the average signal level and the absolute value of any change in average signal level, and comparing the derived parameter values with corresponding predetermined threshold values. In order to further minimize clipping and false alarms, the VAD periodically monitors and updates the threshold values to reflect changes in the level of background noise.
摘要翻译：语音活动检测器（VAD），其通过导出测量输入信号的短期时域特性的参数（包括平均信号电平和平均信号电平的任何变化的绝对值）来确定输入信号是否包含语音，以及比较导出参数值与相应的预定阈值。为了进一步最小化削波和误报警，VAD周期性地监视和更新阈值以反映背景噪声电平的变化。

3. 发明授权

US5649055A Voice activity detector for speech signals in variable background noise 失效
标题翻译：用于可变背景噪声的语音信号的语音活动检测器
公开(公告)号：US5649055A
公开(公告)日：1997-07-15
申请号：US536507
申请日：1995-09-29
申请人： Prabhat K. Gupta , Shrirang Jangi , Allan B. Lamkin , W. Robert Kepley, III , Adrian J. Morris
发明人： Prabhat K. Gupta , Shrirang Jangi , Allan B. Lamkin , W. Robert Kepley, III , Adrian J. Morris
IPC分类号： G10L25/09 , G10L25/78 , G10L9/00
CPC分类号： G10L25/78 , G10L2025/786 , G10L25/09
摘要： A voice activity detector (VAD) which determines whether received voice signal samples contain speech by deriving parameters measuring short term time domain characteristics of the input signal, including the average signal level and the absolute value of any change in average signal level, and comparing the derived parameter values with corresponding thresholds, which are periodically monitored and updated to reflect changes in the level of background noise, thereby minimizing clipping and false alarms.
摘要翻译：语音活动检测器（VAD），其通过导出测量输入信号的短期时域特性的参数（包括平均信号电平和平均信号电平的任何变化的绝对值）来确定接收到的语音信号样本是否包含语音，并将具有相应阈值的导出参数值，其被周期性地监视和更新，以反映背景噪声水平的变化，从而最小化削波和误报警。

4. 发明授权

US5533133A Noise suppression in digital voice communications systems 失效
标题翻译：数字语音通信系统中的噪声抑制
公开(公告)号：US5533133A
公开(公告)日：1996-07-02
申请号：US37946
申请日：1993-03-26
申请人： Allan Lamkin , W. Robert Kepley, III , Prabhat K. Gupta , Adrian J. Morris
发明人： Allan Lamkin , W. Robert Kepley, III , Prabhat K. Gupta , Adrian J. Morris
IPC分类号： H03G3/34 , H04B15/00
CPC分类号： H03G3/341 , H03G3/34
摘要： Noise is suppressed during pauses and silent periods in conversation, and voiced signals are freely passed in a mobile communications system thereby improving the quality of the transmitted speech. Noise suppression is implemented in such a way that a low level of noise is still allowed to pass to provide presence of the remote speaker; that is, the line is not made completely silent as this may falsely indicate that the connection has been interrupted. The noise suppression has an added feature of decreasing the background noise fractionally when voice is no longer detected. This provides perceptually improved quality of the communication.
摘要翻译：在会话中的停顿和静音期间噪声被抑制，并且浊音信号在移动通信系统中自由地通过，从而提高了传输语音的质量。以这样的方式实现噪声抑制，使得仍然允许低水平的噪声通过以提供远程扬声器的存在; 也就是说，该行不会完全无声，因为这可能会错误地指示连接已中断。噪声抑制具有增加的特征，即当不再检测到声音时，分数会降低背景噪声。这提供了明显改善的通信质量。

5. 发明授权

US5455964A Stabilization of frequency and power in an airborne communication system 失效
标题翻译：在机载通信系统中稳定频率和功率
公开(公告)号：US5455964A
公开(公告)日：1995-10-03
申请号：US42426
申请日：1993-03-26
申请人： David A. Roos , John R. Clewer , Seok-Ho Kim , James E. Malcolm , Andrew W. Brandt , Allan A. D'Souza , Adrian J. Morris , Matthew M. Mohebbi
发明人： David A. Roos , John R. Clewer , Seok-Ho Kim , James E. Malcolm , Andrew W. Brandt , Allan A. D'Souza , Adrian J. Morris , Matthew M. Mohebbi
IPC分类号： H03J7/02 , H04B7/185 , H04W48/12 , H04Q7/38 , G01S3/52 , H04B1/10 , H04B7/26
CPC分类号： H04B7/18506 , H03J7/02 , H04W48/12
摘要： The frequency and power of transmissions in a mobile communication system, such as an air-to-ground telephony system, are stabilized without a priori knowledge of the system gain factors or frequency references. The ground station monitors the available channels and modifies a vacant channel broadcast message to provide information that the channel is available. In this way, the air terminals have knowledge of all available channels. The ground station transmits a pilot signal. Upon request by a user for a dial tone at the air terminal, the air terminal selects a vacant channel and scans for the pilot signal. The air terminal estimates a distance to the ground station and sets a power level of a seizing transmission based on the estimated distance. The air terminal also estimates a Doppler frequency shift of the selected channel due to the relative movement of the air terminal with respect to the ground station and sets a frequency of the seizing transmission based on the estimated Doppler frequency shift. The air terminal then transmits a channel seizing signal at a reduced bandwidth less than a full normal bandwidth to the ground station at the set level and frequency. The ground station measures the level and frequency of the seizing signal and transmits to the air terminal information acknowledging the seizure of the selected channel and reporting the level and frequency of the seizing signal. The air terminal corrects the transmitted level and frequency and then switches the transmission bandwidth to the full normal bandwidth at the corrected level.
摘要翻译：移动通信系统（例如空对地电话系统）中的传输的频率和功率在没有系统增益因子或频率参考的先验知识的情况下是稳定的。地面站监视可用频道并修改空闲频道广播消息以提供信道可用的信息。这样，空中终端就可以获得所有可用频道的知识。地面站发送导频信号。根据用户在空中终端的拨号音请求，空中终端选择空闲信道并扫描导频信号。空中终端估计到地面站的距离，并基于估计的距离设置占用传输的功率电平。空中终端还估计由于空中终端相对于地面站的相对移动而选择的信道的多普勒频移，并且基于估计的多普勒频移来设置占用传输的频率。然后，空中终端以设定的等级和频率向地面站发送小于全正常带宽的减少带宽的信道占用信号。地面站测量占用信号的电平和频率，并向空中终端发送确认占用所选频道的信息，并报告占用信号的电平和频率。空中终端校正发送的电平和频率，然后将发送带宽切换到校正电平的完全正常带宽。

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