Apparatus and a method for approximating a first signal using a second signal
View Patent ↗A method for approximating a first signal having a first oscillation period within a quantized time interval using a second signal is provided. The second signal has a second oscillation period. The method includes calculating a phase offset of the first signal at at least one position within the quantized time interval. Further, the method comprises shifting the second signal within the quantized time interval until a phase offset of the second signal at the at least one position satisfies a quality criterion related to the phase offset of the first signal.
1. An apparatus for generating an analog radio frequency signal using a digital signal comprising a radius component and a second component related to an oscillation period of the digital signal, comprising:
a first plurality of digital-to-analog converter cells configured to generate a first contribution to the analog radio frequency signal based on the radius component and a local oscillator signal related to a quantized length of the oscillation period; and
a second plurality of digital-to-analog converter cells configured to generate a second contribution to the analog radio frequency signal based on the local oscillator signal and a quantization error of the quantized length of the oscillation period.
2. The apparatus of claim 1 , wherein the first plurality of digital-to-analog converter cells and the second plurality of digital-to-analog converter cells are comprised by one digital-to-analog converter.
3. The apparatus of claim 1 , wherein the first plurality of digital-to-analog converter cells is comprised by a first digital-to-analog converter, wherein the second plurality of digital-to-analog converter cells is comprised by a second digital-to-analog converter, and wherein the apparatus further comprises a signal combiner configured to combine the first contribution to the analog radio frequency signal and the second contribution to the analog radio frequency signal.
4. The apparatus of claim 1 , wherein the second plurality of digital-to-analog converter cells is further configured to generate the second contribution to the analog radio frequency signal based on the radius component.
5. The apparatus of claim 4 , wherein the apparatus further comprises a weighting unit configured to weight the quantization error with the radius component.
6. The apparatus of claim 5 , wherein the weighting unit is further configured to weight the quantization error with the quantized length of the oscillation period.
7. The apparatus of claim 5 , wherein the weighting unit is further configured to weight the quantization error with a mean value of the quantized length of the oscillation period and the quantized length of at least one further oscillation period of the digital signal.
8. The apparatus of claim 1 , wherein the quantization error represents a mean value of the quantization error of the quantized length of the oscillation period and the quantization error of the quantized length of an adjacent oscillation period of the digital signal.
9. An apparatus for generating an analog radio frequency signal using a sample of a digital signal, comprising:
a first plurality of digital-to-analog converter cells configured to generate a first contribution to the analog radio frequency signal based on a first local oscillator signal; and
a second plurality of digital-to-analog converter cells configured to generate a second contribution to the analog radio frequency signal based on a second local oscillator signal, the second local oscillator signal having a phase shift with respect to the first local oscillator signal,
wherein the first local oscillator signal and the second local oscillator signal are both based on a calculated instantaneous frequency of the radio frequency signal for the sample of the digital signal.
10. The apparatus of claim 9 , wherein a frequency of the first local oscillator signal and a frequency of the second local oscillator signal are both based on the calculated instantaneous frequency of the radio frequency signal for the sample of the digital signal.
11. The apparatus of claim 9 , wherein the first plurality of digital-to-analog converter cells is further configured to generate the first contribution to the analog radio frequency signal based on an first component of the sample, and wherein the second plurality of digital-to-analog converter cells is further configured to generate the second contribution to the analog radio frequency signal based on a second component of the sample.
12. The apparatus of claim 9 , wherein the first plurality of digital-to-analog converter cells and the second plurality of digital-to-analog converter cells are comprised by one digital-to-analog converter.
13. The apparatus of claim 9 , wherein the first plurality of digital-to-analog converter cells is comprised by a first digital-to-analog converter, wherein the second plurality of digital-to-analog converter cells is comprised by a second digital-to-analog converter, and wherein the apparatus further comprises a signal combiner configured to combine the first contribution to the analog radio frequency signal and the second contribution to the analog radio frequency signal.
14. A method for generating an analog radio frequency signal using a digital signal comprising a radius component and a second component related to an oscillation period of the digital signal, comprising:
generating a first contribution to the analog radio frequency signal based on the radius component and a local oscillator signal related to a quantized length of the oscillation period; and
generating a second contribution to the analog radio frequency signal based on the local oscillator signal and a quantization error of the quantized length of the oscillation period.
15. The method of claim 14 , wherein the first contribution to the analog radio frequency signal is generated by a first plurality of digital-to-analog converter cells of a digital-to-analog converter, and wherein the second contribution to the analog radio frequency signal is generated by a second plurality of digital-to-analog converter cells of the digital-to-analog converter.
16. The method of claim 14 , wherein the first contribution to the analog radio frequency signal is generated by a first digital-to-analog converter, wherein the second contribution to the analog radio frequency signal is generated by a second digital-to-analog converter, and wherein the method further comprises combining the first contribution to the analog radio frequency signal and the second contribution to the analog radio frequency signal.
17. The method of claim 14 , wherein generating the second contribution to the analog radio frequency signal is further based on the radius component.
18. The method of claim 17 , wherein the method further comprises weighting the quantization error with the radius component.
19. The method of claim 14 , wherein the method further comprises weighting the quantization error with the quantized length of the oscillation period.
20. The method of claim 14 , wherein the method further comprises weighting the quantization error with a mean value of the quantized length of the oscillation period and the quantized length of at least one further oscillation period of the digital signal.
21. The method of claim 14 , wherein the quantization error represents a mean value of the quantization error of the quantized length of the oscillation period and the quantization error of the quantized length of an adjacent oscillation period of the digital signal.
22. A method for generating an analog radio frequency signal using a sample of a digital signal, comprising:
generating a first contribution to the analog radio frequency signal based on a first local oscillator signal; and
generating a second contribution to the analog radio frequency signal based on a second local oscillator signal, the second local oscillator signal having a phase shift with respect to the first local oscillator signal,
wherein the first local oscillator signal and the second local oscillator signal are both based on a calculated instantaneous frequency of the radio frequency signal for the sample of the digital signal.
23. The method of claim 22 , wherein a frequency of the first local oscillator signal and a frequency of the second local oscillator signal are both based on the calculated instantaneous frequency of the radio frequency signal for the sample of the digital signal.
24. The method of claim 22 , wherein generating the first contribution to the analog radio frequency signal is further based on a first component of the sample, and wherein generating the second contribution to the analog radio frequency signal is further based on a second component of the sample.
25. The method of claim 22 , wherein the first contribution to the analog radio frequency signal is generated by a first plurality of digital-to-analog converter cells of a digital-to-analog converter, and wherein the second contribution to the analog radio frequency signal is generated by a second plurality of digital-to-analog converter cells of the digital-to-analog converter.