Transmitter with reduced power consumption and increased linearity
View Patent ↗The application refers to an apparatus comprising, a signal generator ( 102, 102 a ) configured to generate a signal, a first pulse width modulating unit ( 106 ) configured to modulate the signal, an amplifier unit ( 110 ) configured to amplify the modulated signal, a feedback loop path ( 108 a ) configured to correct the modulated signal using an error signal, wherein the apparatus comprises a second pulse width modulating ( 108 ) unit configured to modulate the error signal onto the modulated signal.
1. An apparatus comprising:
a signal generator configured to generate a signal having an amplitude component and a phase component;
a first pulse position modulating unit configured to modulate the phase component of the generated signal;
a first pulse width modulating unit configured to modulate the amplitude component of the generated signal onto the phase modulated signal;
an amplifier unit configured to amplify the amplitude and phase modulated signal;
a feedback loop path configured to correct the amplitude and phase modulated signal using an error signal; and
a second pulse width modulating unit configured to modulate the error signal onto the amplitude and phase modulated signal.
2. The apparatus according to claim 1 , wherein the signal generator is configured to generate a polar signal.
3. The apparatus according to claim 1 , wherein the amplifying unit is a switching power amplifier.
4. The apparatus according to claim 1 , wherein the apparatus comprises a predistortion unit configured to predistort the generated signal.
5. The apparatus according to claim 1 , wherein the feedback loop path comprises a second pulse position modulating unit configured to modulate an error signal onto the amplitude and phase modulated signal.
6. The apparatus according to claim 1 , wherein the first pulse position modulating unit comprises a first mapping unit configured to map the phase component to at least one suitable function according to a chosen implementation of the first pulse position modulating unit.
7. The apparatus according to claim 1 , wherein the first pulse position modulating unit comprises a first up converting unit.
8. The apparatus according to claim 1 , wherein the first pulse width modulating unit and the first pulse position modulating unit are arranged as one pulse width pulse position modulating unit.
9. The apparatus according to claim 4 , wherein the predistortion unit is configured to determine a phase shift function depending on the generated signal.
10. The apparatus according to claim 4 , wherein the predistortion unit comprises a first determining unit configured to determine a duty cycle function depending on the generated signal.
11. The apparatus according to claim 5 , wherein the second pulse width modulating unit and the second pulse position modulating unit are arranged as one pulse width pulse position modulating unit.
12. The apparatus according to claim 6 , wherein the first pulse width modulating unit comprises a second mapping unit configured to map the phase shift function to at least one suitable function according to a chosen implementation of the first pulse width modulating unit.
13. The apparatus according to claim 7 , wherein the first pulse width modulating unit comprises a second up converting unit.
14. The apparatus according to claim 8 , wherein the feedback loop path comprises a down converting and error detecting unit.
15. The apparatus according to claim 10 , wherein the predistortion unit comprises a second determining unit configured to determine the phase shift function depending on the determined duty cycle function.
16. A method comprising:
generating a signal having an amplitude component and a phase component;
modulating the phase component of the generated signal using pulse position modulation;
modulating the amplitude component of the generated signal onto the phase modulated signal using pulse width modulation;
amplifying the amplitude and phase modulated signal;
generating an error signal in a feedback loop path; and
modulating the error signal onto the amplitude and phase modulated signal using pulse width modulation.
17. A non-transitory computer readable medium having a computer program stored thereon, the computer program comprising instructions operable to cause a processor to perform the method steps of:
generating a signal having an amplitude component and a phase component;
modulating the phase component of the generated signal using pulse position modulation;
modulating the amplitude component of the generated signal onto the phase modulated signal using pulse width modulation;
amplifying the amplitude and phase modulated signal;
generating an error signal in a feedback loop path; and
modulating the error signal onto the amplitude and phase modulated signal.
18. A transmitter comprising an apparatus comprising:
a signal generator configured to generate a signal having an amplitude component and a phase component;
a first pulse position modulating unit configured to modulate the phase component of the generated signal;
a first pulse width modulating unit configured to modulate the amplitude component of the generated signal onto the phase modulated signal;
an amplifier unit configured to amplify the amplitude and phase modulated signal;
a feedback loop path configured to correct the amplitude and phase modulated signal using an error signal; and
a second pulse width modulating unit configured to modulate the error signal onto the amplitude and phase modulated signal.