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公开(公告)号：US3766523A
公开(公告)日：1973-10-16
申请号：US3766523D
申请日：1972-10-04
Applicant: MOTOROLA INC
CPC classification number: H04W84/025 , G08G1/202 , H04L1/00
Abstract: A selective calling sequential tone signalling system for transmitting and receiving predetermined coded messages. A base station and at least one mobile station is provided, and message, status, automatic status and identification codes comprising predetermined format sequences having seven tones each are transmitted therebetween. Automatic message acknowledgment is provided for message receipt verification, and apparatus is provided for substantially eliminating false reception of signals having an improper format.
Abstract translation: 一种用于发送和接收预定编码消息的选择性呼叫顺序音调信令系统。 提供基站和至少一个移动站，并且在它们之间传输包括具有七个音调的预定格式序列的消息，状态，自动状态和识别码。 为消息接收验证提供了自动消息确认，并且提供了用于基本上消除具有不正确格式的信号的错误接收的装置。
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公开(公告)号：US3792290A
公开(公告)日：1974-02-12
申请号：US3792290D
申请日：1973-02-20
Applicant: MOTOROLA INC
Inventor： BROCKER J
CPC classification number: H04W88/027
Abstract: A detector for detecting any one of the particular tone frequency signals in a range of tone frequency signals and which has a constant detection response time includes a converter operative in response to the particular tone frequency signals coupled thereto exceeding a predetermined threshold to develop square wave signals having substantially a 50% duty cycle. An integrator, coupled to the converter integrates the square wave signals to develop an integration voltage. The integration voltage reaches a predetermined amplitude level in response to the square wave signals in the constant detection response time causing actuation of a switching circuit which develops a detection signal.
Abstract translation: 用于检测音调频率信号范围内的特定音频信号中的任何一个并具有恒定检测响应时间的检测器包括响应于耦合到其上的特定音频信号超过预定阈值而操作以转换方波信号的转换器 具有基本上50％的占空比。 耦合到转换器的积分器集成了方波信号以开发积分电压。 积分电压响应于恒定检测响应时间中的方波信号而达到预定的幅度电平，导致产生检测信号的开关电路的致动。
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