发明名称 Automatic frequency control system, operation control method thereof and mobile communication device using the same
摘要 In a mobile communication device, communication can be resumed upon next communication without causing problem even when an AFC control signal becomes abnormal upon interruption of communication. Locked state and unlocked state of an AFC portion is monitored by an AFC monitoring portion 5. Upon interruption of communication, if in unlocked state, a TCXO 1 is controlled by the AFC portion using a TCXO control signal upon preceding locked state. By this, when communication failure is caused by influence of building, tunnel or the like or when communication is terminated, a reference frequency of the mobile communication device does not significantly offset from the reference frequency of a base station to facilitate communication upon next communication.
申请公布号 US7027787(B2) 申请公布日期 2006.04.11
申请号 US20030633717 申请日期 2003.08.05
申请人 NEC CORPORATION 发明人 HIRATA MASARU
分类号 H04B1/18;H04B7/26;H03J7/02;H03J7/04 主分类号 H04B1/18
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