US 5,212,827 AGranted

Zero intermediate frequency noise blanker

AssigneeMotorola, Inc.

InventorsWilliam R. Meszko, Joseph P. Heck

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Abstract

An essentially zero intermediate frequency receiver (100) for recovering an information signal from a received signal (110), which includes means for blanking noise signals which may otherwise deteriorate performance, comprises a receiver (10) for recovering the information signal and a noise blanker (28). The receiver (28) comprises at least one conversion mixer (32B) for operating on the received signal (110) to provide an essentially baseband signal (125B), at least one delay filter (40B) coupled to the conversion mixer (32B) for producing a delayed essentially baseband signal, and at least one blanker switch (S1-S4) for operating on the delayed essentially baseband signal to temporarily prevent recovery of the information signal in response to a control signal (58). To provide the control signal (58), the noise blanker (28) is coupled to the receiver (10) for operating on either the essentially baseband signal (125B) or the received signal (110) as a noise blanker input signal.

Claims15

Dependent claims

An essentially zero intermediate frequency receiver for recovering an information signal from a received signal said receiver comprising:

receiver means for recovering said information signal comprising:
a first conversion means for operating on said received signal to provide an essentially baseband inphase signal;
a second conversion means for operating on said received signal to provide an essentially baseband quadrature signal;
a first delay means coupled to said first conversion means for producing a delayed essentially baseband inphase signal;
a second delay means coupled to said second conversion means for producing a delayed essentially baseband quadrature signal;
at least one blanker switch means for operating on said delayed essentially baseband signals to temporarily prevent recovery of said information signal in response to a switch control signal;
means for providing a gain control signal;
and
noise blanking means for blanking noise signals which may otherwise deteriorate performance, said noise blanking means coupled to said receiver means for operating on either at least one of said essentially baseband signals or said received signal as a noise blanker input signal to provide said switch control signal;
said noise blanking means comprising;
input filtering means for filtering said noise blanker input signal to provide a filtered signal;
amplifier means for amplifying said filtered signal, in response to said gain control signal, to provide an amplified signal;
and
means for generating said switch control signal from said amplified signal.

11 more elements

An essentially zero intermediate frequency receiver for recovering an information signal from a received signal said receiver comprising:

means for splitting said received signal into a pair of input signals;
receiver means for recovering said information signal comprising:
at least one conversion means for operating on each one of said pair of input signals to provide a pair of essentially baseband signals in phase quadrature;
at least one lowpass delay means coupled to each one of said conversion means for producing a pair of delayed essentially baseband signals in phase quadrature;
and
at least one blanker switch means for operating on said pair of delayed essentially baseband signals to temporarily prevent recovery of said information signal in response to a control signal;
means for providing an automatic gain control (AGC) signal for controlling the sensitivity of a noise blanking means;
and
said noise blanking means for blanking noise signals which may otherwise deteriorate performance, said noise blanking means coupled to an output of at least one of said conversion means to provide a noise blanker input signal for operating on at least one of said essentially baseband signals to provide said control signal;
said noise blanking means comprising:
input filtering means for filtering at least one of said essentially baseband signals to provide a filtered signal;
amplifier means for amplifying said filtered signal, in response to said gain control signal, to provide an amplified signal;
and
means for generating said switch control signal from said amplified signal.

11 more elements

An essentially zero intermediate frequency receiver for recovering an information signal from a received signal, said receiver comprising:

means for splitting said received signal into first, second, and third input signals;
receiver means for recovering said information signal comprising:
at least one conversion means for operating on each one of said first and second input signals to provide a pair of essentially baseband signals in phase quadrature;
at least one lowpass delay means coupled to each one of said conversion means for producing a pair of delayed essentially baseband signals in phase quadrature;
and
at least one blanker switch means for operating on said pair of delayed essentially baseband signals to temporarily prevent recovery of said information signal in response to a control signal;
and
means for providing an automatic gain control (AGC) signal for controlling the sensitivity of a noise blanking means;
and
said noise blanking means coupled to an input of said conversion means for operating on said third input signal to provide said control signal;
said noise blanking means comprising:
input filtering means for filtering said third input signal to provide a filtered signal;
amplifier means for amplifying said filtered signal, in response to said AGC signal, to provide an amplified signal;
and
means for generating said switch control signal from said amplified signal.

12 more elements

Dependencies are inferred from the claim text.