Method and device for phase and/or pulse-width modulation
AssigneeIHP GmbH
InventorJohann Christoph Scheytt
Life of this patent
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Abstract
The present invention relates to a device (2000) and a method for encoding an input signal (102) into a digital pulse-width and/or phase modulated output signal (162). The present invention also relates to a transmission method, a power amplifier and a transmitter. With the aid of a mapping process comprising at least three-stages, a sequence of output pulses (162) is generated which corresponds on average over time to a theoretical, previously computed target pulse. In this way, the device (2000) or the method can be digitally implemented and a large part (100, 110) of the device (2000) can also be operated at a clock rate that is substantially lower than a clock rate of the output signal generator (200, 220).
Claims14
A device (1000;
- 2000) for encoding an input signal (102) into a digital pulse-width and/or phase modulated output signal (162), said signal being referred to hereinafter as a digital output signal (162), said device comprising:
- an input for receiving the input signal (102) and an output for outputting the digital output signal (162),
- a phase encoder (100) configured to derive a binary first start phase word (104) and a binary first terminal phase word (106) with a first resolution from the input signal (102), wherein
- the first start phase word (104) determines a starting time within an encoding period, at which a rising edge of a target pulse (108) is to occur in the digital output signal (162), and the first terminal phase word (106) determines a termination point within the encoding period, at which a falling edge of the target pulse (108) is to occur in the digital output signal (162),
- a phase interpolator (110) connected downstream from the phase encoder (100) and configured to convert the first start phase word (104) into a plurality of second binary start phase words (114.1 . . . M) and the first terminal phase word (106) into a plurality of second binary terminal phase words (116.1 . . . M), with a second resolution that is smaller than the first resolution,
- wherein a respective second start phase word describes one of N possible discrete times in the encoding period and thus approximately determines the starting time with the second resolution, and a respective second terminal phase word describes one of the N possible discrete times in the encoding period and thus approximately determines the termination point with the second resolution, and
- an output signal generator (130, 140, 150, 160;
- 200, 220) configured to convert the plurality of second start phase words (114.1 . . . M) and the plurality of second terminal phase words (116.1 . . . M) into a serial sequence of output pulses and to output these as an output signal (162) via the output, the serial sequence of output pulses corresponding on average over time to the target pulse (108).
A method for encoding an input signal (102) into a digital pulse-width and/or phase modulated output signal (162), referred to hereinafter as a digital output signal (162), comprising the steps of:
- receiving the input signal,
- deriving a binary first start phase word (104) and a binary first terminal phase word (106) from the input signal, with a first resolution, wherein
- the first start phase word (104) determines a starting time within an encoding period, at which a rising edge of a target pulse (108) is to occur in the digital output signal (162), and the first terminal phase word (106) determines a termination point within the encoding period, at which a falling edge of the target pulse (108) is to occur in the digital output signal (162),
- converting the first start phase word (104) into a plurality of second binary start phase words (114.1 . . . M) and the first terminal phase word (106) into a plurality of second binary terminal phase words (116.1 . . . M), with a second resolution that is smaller than the first resolution, wherein
- a respective second start phase word describes one of N possible discrete times in the encoding period and thus approximately determines the starting time with the second resolution, and a respective second terminal phase word describes one of the N possible discrete times in the encoding period and thus approximately determines the termination point with the second resolution,
- converting the plurality of second start phase words (114.1 . . . M) and the plurality of second terminal phase words (116.1 . . . M) into a serial sequence of output pulses, the serial sequence of output pulses corresponding on average over time to the target pulse (108), and
- outputting the serial sequence of output pulses as a digital output signal (162).
Dependencies are inferred from the claim text.