| 摘要 |
Methods and apparatus for reducing the bandwidth of modulation signals in a phase path of a polar modulation transmitter. An exemplary method includes generating a phase difference modulation signal for a phase path of a polar modulation transmitter, and filtering the phase difference modulation signal using a linear-phase filter. Filtering the phase difference modulation signal may be performed by first detecting samples in the phase difference modulation signal that have phase difference values in excess of a phase difference threshold and then filtering samples in the vicinity of the threshold-violating samples to remove the threshold-violating events. Alternatively, all samples may be filtered, i.e., without regard as to whether any given sample exceeds a phase difference threshold, to remove large phase difference changes in the phase difference modulation signal, or a combination of linear-phase and nonlinear filters may be used to remove the large phase difference changes. |
