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公开(公告)号：US06476745B1
公开(公告)日：2002-11-05
申请号：US09447507
申请日：1999-11-23
IPC分类号： H03M118
CPC分类号： H04B14/046 , H03M1/183
摘要： An Automatic Gain Control System for voice codecs used in a digital wireless handset or in any other environment where there is a large amount of background noise. The invention utilizes the processing power available in Digital Signal Processor 111 to adaptively adjust the gain of amplifier 202 and filter 205 in the transmit channel to eliminate audio distortion in a “loud talker” environment. The gain correction information is transmitted by the DSP 111 to the digital filter and PCM I/O block 204 in the 3 unused bits of the 16 bit PCM data word thus eliminating any additional connections.
摘要翻译： 用于数字无线手机或任何其他背景噪音大的环境中的语音编解码器的自动增益控制系统。 本发明利用数字信号处理器111中可用的处理能力自适应地调整发射信道中的放大器202和滤波器205的增益，以消除“大声说话者”环境中的音频失真。 增益校正信息由DSP111发送到16位PCM数据字的3个未使用位中的数字滤波器和PCM I / O块204，从而消除任何附加连接。
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公开(公告)号：US4398735A
公开(公告)日：1983-08-16
申请号：US306371
申请日：1981-09-28
申请人： Brian L. Evans , Robert R. Woodcock
发明人： Brian L. Evans , Robert R. Woodcock
CPC分类号： A63C17/012 , A63C17/01 , A63C17/015
摘要： There is disclosed an entirely new configuration for a truck for skateboards, roller skates, and the like including a baseplate adapted to be connected to the underside of a skate, an elongate beam made from a flexible material, one end of the beam being connected to the baseplate and the beam extending at an acute angle relative thereto, and an elongate axle or axle hub rigidly connected to the other end of the beam and extending perpendicular thereto. The baseplate, the beam, and the axle or axle hub are a one-piece assembly made from a plastic material. An axle may extend through the hub for receipt of conventional wheels.
摘要翻译： 公开了一种用于滑板，溜冰鞋等的卡车的全新配置，其包括适于连接到溜冰鞋下侧的基板，由柔性材料制成的细长梁，梁的一端连接到 所述基板和所述梁以相对于其倾斜的角度延伸，以及细长的轴或轴毂，其刚性地连接到所述梁的另一端并垂直于其延伸。 底板，梁和轴或轮毂是由塑料材料制成的一体式组件。 轴可以延伸穿过轮毂以接收常规车轮。
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3.发明授权Efficient digital ITU-compliant zero-buffering DTMF detection using the non-uniform discrete Fourier transform 失效使用非均匀离散傅里叶变换的高效数字ITU兼容零缓冲DTMF检测公开(公告)号：US06608896B2
公开(公告)日：2003-08-19
申请号：US10021397
申请日：2001-12-07
IPC分类号： H04M300
CPC分类号： H04M7/1295 , H04Q1/4575
摘要： Computationally efficient DTMF detection methods and apparatus are presented that meet all of the ITU recommendations using the modified non-uniform DFT. The system of the present invention employs a high band filter block and two low band filter blocks to detect power at the 8 DTMF tones. The frame length of the high band filter blocks is one half the length of the low band filter blocks. The frame lengths are chosen to meet the ITU frequency selectivity requirements for all DTMF frequencies. The frames of the two low band filter blocks are staggered to produce outputs alternately, and are aligned with respect to the frame of the high band filter block to produce low band filter block outputs that coincided with the high band filter block outputs without the need for signal buffering. A system of power level tests are employed in conjunction with a system of timing tests to ensure that all ITU timing and frequency constraints are met. The present invention requires no buffering of input samples, and can perform DTMF decoding of 24 telephone channels of a T1 time-division multiplexed communication line, using a single fixed-point commercially available digital signal processor.
摘要翻译： 提出了使用改进的非均匀DFT来满足国际电联所有ITU建议的计算高效DTMF检测方法和装置。 本发明的系统采用高频带滤波器模块和两个低频带滤波器块来检测8个DTMF音调的功率。 高频带滤波器块的帧长度是低频带滤波器块的长度的一半。 选择帧长度以满足所有DTMF频率的ITU频率选择性要求。 两个低频带滤波器块的帧被交错以交替地产生输出，并且相对于高频带滤波器块的帧被对准以产生与高频带滤波器块输出一致的低频带滤波器块输出，而不需要 信号缓冲。 功率电平测试系统与定时测试系统一起使用，以确保满足所有ITU定时和频率限制。 本发明不需要输入采样的缓冲，并且可以使用单个定点市售的数字信号处理器对T1时分复用通信线路的24个电话信道进行DTMF解码。
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公开(公告)号：US06370244B1
公开(公告)日：2002-04-09
申请号：US09054872
申请日：1998-04-03
IPC分类号： H04M300
CPC分类号： H04M7/1295 , H04Q1/4575
摘要： Computationally efficient DTMF detection methods and apparatus are presented that meet all of the ITU recommendations using the modified non-uniform DFT. The system of the present invention employs a high band filter block and two low band filter blocks to detect power at the 8 DTMF tones. The frame length of the high band filter blocks is one half the length of the low band filter blocks. The frame lengths are chosen to meet the ITU frequency selectivity requirements for all DTMF frequencies. The frames of the two low band filter blocks are staggered to produce outputs alternately, and are aligned with respect to the frame of the high band filter block to produce low band filter block outputs that coincided with the high band filter block outputs without the need for signal buffering. A system of power level tests are employed in conjunction with a system of timing tests to ensure that all ITU timing and frequency constraints are met. The present invention requires no buffering of input samples, and can perform DTMF decoding of 24 telephone channels of a T1 time-division multiplexed communication line, using a single fixed-point commercially available digital signal processor.
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