| 摘要 |
An RF transmitter ( 10 ) includes a linear predistorter ( 22 ) and a nonlinear predistorter ( 24 ) which together drive analog transmitter components ( 14 ). The linear and nonlinear predistorters ( 22, 24 ) are implemented using a collection of adaptive equalizers ( 30 ). A feedback signal ( 20 ) is developed by downconverting an RF communication signal ( 16 ) obtained from the analog components ( 14 ). The feedback signal ( 20 ) are used in driving tap coefficients ( 34 ) for the adaptive equalizers ( 30', 30 '') in the nonlinear predistorter ( 24 ). An intermodulation-product canceller ( 94 ) uses signal cancellation to cancel intermodulation products from the feedback signal ( 20 ) and generate an intermodulation-neutralized feedback signal ( 96 ). The intermodulation-neutralized feedback signal ( 96 ) is used along with a modulated convergence factor ( 43 ) in driving tap coefficients ( 34 ) for the adaptive equalizer ( 30 ) in the linear predistorter ( 22 ).
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