| 摘要 |
A peak power regulator is disclosed that functions within a Code Division Multiple Access (CDMA) transmitter to reduce peak power spikes within baseba nd signals, controlling the out-of-band emissions, and maintaining the in-band signal quality within an acceptable degradation. In-phase and quadrature baseband signals are input to an envelope magnitude predictor within the pea k power regulator. The envelope magnitude predictor outputs an estimate for th e magnitude of the envelope that will be generated when the inputted baseband signals are modulated. This estimate is input to a multiplier that generates a ratio by dividing the estimate by a maximum acceptable envelope magnitude. T he ratio is subsequently input to a mapping table that outputs a scaling factor sufficient for reducing peak power spikes. The scaling factor is subsequentl y substracted from a value of one and multiplied by first delayed versions of the in-phase and quadrature baseband input signals. The outputs from these multiplication operations, after being filtered within lowpass filters to remove out-of-band emissions caused by the operations, are referred to as excess power correction signals. These excess power correction signals are then substracted from second delayed versions of the in-phase and quadrature baseband input signals to generate in-phase and quadrature baseband output signals. |
