Radio receiver utilizing a single analog to digital converter
View Patent ↗A radio receiver includes a single analog to digital converter, a 1 st digital mixing module, and a 2 nd digital mixing module. The single analog to digital converter is coupled to convert the filtered IF signal into a digital IF signal, which includes information regarding an in-phase component and a quadrature component of a modulated RF signal. The 1 st and 2 nd mixing modules each receive the digital IF signal and mix the digital IF signal with an in-phase and quadrature digital local oscillation to produce a 1 st baseband signal component and a 2 nd baseband signal component.
1. A radio receiver comprises:
an analog to digital converter coupled to convert an Intermediate Frequency (IF) signal into a digital IF signal, wherein the IF signal includes information regarding an in-phase component and a quadrature component of a modulated RF signal;
a first digital mixing module coupled to process the digital IF signal with an in-phase digital local oscillation to produce a first baseband signal component;
a second digital mixing module coupled to process the digital IF signal with a quadrature digital local oscillation to produce a second baseband signal component; and
a complex bandpass filter coupled to filter the in-phase component and the quadrature component of the modulated RF signal.
2. The radio receiver of claim 1 , wherein:
the radio receiver is one of a laptop host computer, a personal digital assistant host, a personal computer host, and a cellular telephone host.
3. The radio receiver of claim 1 , wherein the analog to digital converter further comprises:
a continuous time delta sigma analog to digital converter; or
a flash analog to digital converter.
4. The radio receiver of claim 1 , wherein the first digital mixing module comprises:
a digital mixer coupled to mix the digital IF signal with the in-phase digital local oscillation to produce a first mixed signal;
a low pass decimation filter coupled to process the first mixed signal to produce a decimated mixed signal; and
a digital gain control module coupled to adjust magnitude of the decimated mixed signal to produce the first baseband signal component.
5. The radio receiver of claim 4 , wherein the low pass decimation filter comprises:
a low pass filter coupled to low pass filter the first mixed signal to produce a filtered mixed signal; and
a down sampling module coupled to down sample the filtered mixed signal to produce the decimated mixed signal.
6. The radio receiver of claim 1 , wherein the second digital mixing module comprises:
a digital mixer coupled to mix the digital IF signal with the quadrature digital local oscillation to produce a second mixed signal;
a low pass decimation filter coupled to process the second mixed signal to produce a decimated mixed signal; and
a digital gain control module coupled to adjust magnitude of the decimated mixed signal to produce the second baseband signal component.
7. The radio receiver of claim 6 , wherein the low pass decimation filter comprises:
a low pass filter coupled to low pass filter the second mixed signal to produce a filtered mixed signal; and
a down sampling module coupled to down sample the filtered mixed signal to produce the decimated mixed signal.
8. A method for digital intermediate frequency (IF) to baseband conversion from a single IF signal, the method comprises:
receiving the single IF signal;
employing an analog-to-digital converter to perform analog-to-digital converting of the single IF signal into a single digital IF signal, wherein the single digital IF signal includes information regarding an in-phase component and a quadrature component of a modulated RF signal;
mixing the single digital IF signal with a first digital local oscillation to produce a first digitally mixed signal;
mixing the single digital IF signal with a second digital local oscillation to produce a second digitally mixed signal;
decimation filtering the first digitally mixed signal to produce a first baseband signal component; and
decimation filtering the second digitally mixed signal to produce a second baseband signal component; and wherein:
the decimation filtering of the first digitally mixed signal includes:
low pass filtering the first digitally mixed signal to produce a filtered signal; and
down sampling the filtered signal to produce the first baseband signal component.
9. The method of claim 8 further comprises:
adjusting gain of the first baseband signal component in accordance with baseband processing; and
adjusting gain of the second baseband signal component in accordance with the baseband processing.
10. The method of claim 8 , wherein:
the method is performed within one of a laptop host computer, a personal digital assistant host, a personal computer host, and a cellular telephone host.
11. The method of claim 8 , wherein the decimation filtering of the second digitally mixed signal comprises:
low pass filtering the second digitally mixed signal to produce a filtered signal; and
down sampling the filtered signal to produce the second baseband signal component.
12. An apparatus for digital intermediate frequency (IF) to baseband conversion from a single IF signal, the apparatus comprises:
processing module; and
memory coupled to the processing module, wherein the memory includes operational instructions that cause the processing module to:
receive the single IF signal;
perform analog-to-digital converting of the IF signal into a single digital IF signal, wherein the single digital IF signal includes information regarding an in-phase component and a quadrature component of a modulated radio frequency (RF) signal;
mix the single digital IF signal with a first digital local oscillation to produce a first digitally mixed signal;
mix the single digital IF signal with a second digital local oscillation to produce a second digitally mixed signal;
decimation filter the first digitally mixed signal to produce a first baseband signal component; and
decimation filter the second digitally mixed signal to produce a second baseband signal component; and wherein:
the memory comprises operational instructions that cause the processing module to decimation filter the first digitally mixed signal by:
low pass filtering the first digitally mixed signal to produce a filtered signal; and
down sampling the filtered signal to produce the first baseband signal component.
13. The apparatus of claim 12 , wherein the memory further comprises operational instructions that cause the processing module to:
adjust gain of the first baseband signal component in accordance with baseband conversion; and
adjust gain of the second baseband signal component in accordance with the baseband conversion.
14. The apparatus of claim 12 , wherein:
the apparatus is one of a laptop host computer, a personal digital assistant host, a personal computer host, and a cellular telephone host.
15. The apparatus of claim 12 , wherein the memory comprises operational instructions that cause the processing module to decimation filter the second digitally mixed signal by:
low pass filtering the second digitally mixed signal to produce a filtered signal; and
down sampling the filtered signal to produce the second baseband signal component.