Transmitter with a reduced complexity digital up-converter

摘要

The present disclosure is directed to a system and method for performing digital up-conversion of a signal to a desired RF carrier frequency. The system and method efficiently perform digital up-conversion of the signal, in one example, by controlling a sample clock that is used by a DAC to sample and convert the up-converted signal from the digital domain to the analog domain to have a frequency that is four or eight times the desired RF carrier frequency. By controlling the sample clock of the DAC to have a frequency that is four or eight times the desired RF carrier frequency, the system and method can be implemented using currently available IC process geometries such that the implementation consumes much less area and/or power than an analog up-converter configured to have equivalent up-conversion functionality.

主权项

1. A transmitter comprising:
a sample clock generator configured to generate a sample clock to have a frequency that is 4, 8, or 8/3 times a carrier frequency plus an offset frequency; an intermediate frequency (IF) digital frequency-shifter configured to frequency-shift a baseband signal by the offset frequency divided by 4, 8, or 8/3 to provide an IF signal; a radio frequency (RF) digital up-converter configured to up-convert the IF signal to provide a digital RF signal at the carrier frequency; and a digital-to-analog converter (DAC) configured to sample the digital RF signal using the sample clock and convert the samples of the digital RF signal to an analog RF signal for transmission over a channel.