| 摘要 |
<p>An amplifier distortion reduction system (80) detects a plurality of amplitudes corresponding in time within a frequency band of operation. In response to at least one of the plurality of amplitudes, adjustments can be made to components within the frequency band of operation, enabling the amplifier distortion reduction system to adapt to changing operating conditions. For example, processing circuitry can use time samples to produce a frequency spectrum representation of the frequency band of operation. The processing circuitry can include an analog to digital (A/D) converter (88) which samples and converts the radio frequency (RF) signals over the frequency band of operation into digital sample values. A digital receiver (90) transforms the digital sample values to produce a digital domain frequency spectrum representation of the frequency band of operation, for example using a Fourier Transform. The frequency spectrum representation can be a plurality of amplitudes within the frequency band of operation which correspond in time, such as a plurality of amplitudes over frequency representing the frequency spectrum at a given instant in time. In response to the frequency spectrum representation, the digital receiver provides adjustments for components in the frequency band of operation to improve the performance of the amplitude distortion reduction system. In a feed forward embodiment, the output of the carrier cancellation loop can be monitored and equalizer adjustments provided to reduce the amplitude of the carrier signal(s) equally over the frequency band of operation. The output of the IMD cancellation loop (86) can be monitored and equalizer adjustments provided to reduce the IMD components equally over the frequency band of operation. Thus, the processing circuitry can monitor amplitudes corresponding in time over the frequency band and provide improved performance over the frequency band. <IMAGE></p> |
