调频接收器中基于干扰信号检测的自适应锁相环路带宽调整

Jammer detection based adaptive pll bandwidth adjustment in fm receiver

Abstract

FM接收器内的频率合成器使用锁相环路PLL来产生本机振荡器LO信号。将所述LO信号供应到混频器。所述FM接收器还包括干扰信号检测功能性。如果未检测到干扰信号,那么将所述PLL的环路带宽设定成具有相对较高的值,借此有利于抑制带内残余FM。如果检测到干扰信号,那么将所述PLL的所述环路带宽设定成具有相对较低的值,借此有利于抑制带外SSB相位噪声。通过视是否检测到干扰信号而定自适应地改变环路带宽,可放宽对所述PLL内的支路的性能要求,同时仍满足带内残余FM要求及带外SSB相位噪声要求。通过允许所述PLL的VCO因环路带宽的所述自适应改变而产生更多相位噪声,可减少VCO功率消耗。
A frequency synthesizer within an FM receiver employs a Phase-Locked Loop (PLL) to generate a Local Oscillator (LO) signal. The LO signal is supplied to a mixer. The FM receiver also includes jammer detection functionality. If no jammer is detected, then the loop bandwidth of the PLL is set to have a relatively high value, thereby favoring suppression of in-band residual FM. If a jammer is detected, then the loop bandwidth of the PLL is set to have a relatively low value, thereby favoring suppression of out-of-band SSB phase noise. By adaptively changing loop bandwidth depending on whether a jammer is detected, performance requirements on sub-circuits within the PLL can be relaxed while still satisfying in-band residual FM and out-of-band SSB phase noise requirements. By allowing the VCO of the PLL to generate more phase noise due to the adaptive changing of loop bandwidth, VCO power consumption can be reduced.

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Patent Citations (6)

    Publication numberPublication dateAssigneeTitle
    CN-1138394-ADecember 18, 1996普罗克西姆公司采用差分四级移频键控的数字通信设备
    CN-1909373-AFebruary 07, 2007瑞昱半导体股份有限公司Method and circuit for developing spread-spectrum or overfrequency clock
    EP-1560390-A1August 03, 2005AlcatelAdaptive control of the bandwidth of a carrier recovery loop in presence of local oscillator phase noise
    US-2007232219-A1October 04, 2007Wei XiongMethods and apparatus for digital jammer detection
    US-4479091-AOctober 23, 1984Alps Electric Co., Ltd.Phase locked loop FM demodulator with variable bandwidth loop filter

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