| 摘要 |
<p>A Cartesian loop system for radio transmitters in which at least part of the baseband processing is carried out in the digital domain. Digital processing circuitry (250) combines a baseband input signal with a Cartesian feedback signal (206, 207) to generate a forward signal. Analog circuitry (221, 201, 203, 204) converts the forward signal into a transmission output signal and generates the Cartesian feedback signal. Preferably the digital processing circuitry applies a phase shift process (208) to the Cartesian feedback signal before combination with the baseband input signal. The system is programmable allowing a single device to be used in a range of transmitters under different radio standards.</p> |
