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公开(公告)号：DE69525049D1
公开(公告)日：2002-02-21
申请号：DE69525049
申请日：1995-04-28
Applicant: QUALCOMM INC
Inventor： PETERZELL E , WILSON B , BLACK J
Abstract: An automatic gain control (AGC) apparatus for a digital receiver is disclosed herein. The AGC apparatus includes an adjustable gain amplifier having an input port for receiving an input signal, a control port for receiving a gain control signal, and an output port for providing an output signal. The AGC apparatus further includes a measurement circuit for generating a received power signal based on the power of the output signal. A saturating integrator compares the received power signal to a reference signal and generates an gain control signal in response to a result of the comparison. The saturating integrator includes a decision circuit for enabling integration based on values of the received power signal, the reference signal, and the gain control signal. In a preferred implementation the utilization of an input limiter in conjunction with an analog to digital converter enables accommodation of an increased input signal dynamic range. Accordingly, the AGC apparatus is capable of being used in digital demodulation of FM signals. The AGC apparatus may also be employed within a dual mode receiver designed to process both FM and code division multiple access (CDMA) input signals.
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公开(公告)号：DE69525049T2
公开(公告)日：2002-08-29
申请号：DE69525049
申请日：1995-04-28
Applicant: QUALCOMM INC
Inventor： PETERZELL E , WILSON B , BLACK J
Abstract: An automatic gain control (AGC) apparatus for a digital receiver is disclosed herein. The AGC apparatus includes an adjustable gain amplifier having an input port for receiving an input signal, a control port for receiving a gain control signal, and an output port for providing an output signal. The AGC apparatus further includes a measurement circuit for generating a received power signal based on the power of the output signal. A saturating integrator compares the received power signal to a reference signal and generates an gain control signal in response to a result of the comparison. The saturating integrator includes a decision circuit for enabling integration based on values of the received power signal, the reference signal, and the gain control signal. In a preferred implementation the utilization of an input limiter in conjunction with an analog to digital converter enables accommodation of an increased input signal dynamic range. Accordingly, the AGC apparatus is capable of being used in digital demodulation of FM signals. The AGC apparatus may also be employed within a dual mode receiver designed to process both FM and code division multiple access (CDMA) input signals.
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公开(公告)号：DE69533405T2
公开(公告)日：2005-09-01
申请号：DE69533405
申请日：1995-12-11
Applicant: QUALCOMM INC
Inventor： WHEATLEY E , PETERZELL E , KORNFELD K , WEILAND L
IPC: H04B1/06 , H03G1/00 , H03G3/30 , H04B20060101 , H04B1/10 , H04B1/16 , H04B1/18 , H04B1/40 , H04B1/7075 , H04B1/7097 , H04B3/06 , H04B7/005 , H04B7/26 , H04B15/00
Abstract: An apparatus to increase a radio receiver's immunity to radio frequency interference, the radio receiver receiving a signal, the apparatus comprising: a switch (1105) coupled to the received signal, the switch (1105) having an open position and a closed position; a resistance (1101), a first end of the resistance (1101) being coupled to the closed position of the switch (1105) and a second end of the resistance (1101) being coupled to a ground potential; an amplifier (1101) having an input coupled to the open position of the switch (1105), for generating an amplified received signal at an output; a controller coupled to the switch (1105), for switching the switch (1105) to the closed position in response to the received signal exceeding a predetermined power level, said received signal conducting through said switch (1105) and said resistance (1101) to ground potential when said switch (1105) is in said closed position; and said resistance (1101) creating an impedance mismatch at the input to said amplifier (1110) when said switch (1105) is in closed position, thereby reducing the gain contributed by said amplifier (1110).
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公开(公告)号：DE69533405D1
公开(公告)日：2004-09-23
申请号：DE69533405
申请日：1995-12-11
Applicant: QUALCOMM INC
Inventor： WHEATLEY E , PETERZELL E , KORNFELD K , WEILAND L
IPC: H04B1/06 , H03G1/00 , H03G3/30 , H04B20060101 , H04B1/10 , H04B1/16 , H04B1/18 , H04B1/40 , H04B1/7075 , H04B1/7097 , H04B3/06 , H04B7/005 , H04B7/26 , H04B15/00
Abstract: An apparatus to increase a radio receiver's immunity to radio frequency interference, the radio receiver receiving a signal, the apparatus comprising: a switch (1105) coupled to the received signal, the switch (1105) having an open position and a closed position; a resistance (1101), a first end of the resistance (1101) being coupled to the closed position of the switch (1105) and a second end of the resistance (1101) being coupled to a ground potential; an amplifier (1101) having an input coupled to the open position of the switch (1105), for generating an amplified received signal at an output; a controller coupled to the switch (1105), for switching the switch (1105) to the closed position in response to the received signal exceeding a predetermined power level, said received signal conducting through said switch (1105) and said resistance (1101) to ground potential when said switch (1105) is in said closed position; and said resistance (1101) creating an impedance mismatch at the input to said amplifier (1110) when said switch (1105) is in closed position, thereby reducing the gain contributed by said amplifier (1110).
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