Digital transmitter with constrained envelope and spectral regrowth over a plurality of carriers

摘要

A constrained-envelope digital communications transmitter ( 10 ) places constraints on the envelope of spectrally constrained, digitally modulated communication signals ( 46 ) converted into diverse frequency channels ( 54 ) and combined into a composite signal ( 58 ). The envelope constraints achieve lower peak-to-average power ratio without allowing significant spectral regrowth. The composite signal ( 58 ) is applied to a plurality of cascade-coupled constrained-envelope generators ( 64 ). Each constrained-envelope generator ( 64 ) detects overpeak events ( 66 ) and configures corrective impulses ( 68 ) for the overpeak events ( 66 ). The corrective impulses ( 68 ) are distributed to the respective frequency channels ( 54 ) in accordance with a predetermined distribution profile ( 102 ) and are filtered into allocated shaped pulses ( 120 ) that exhibit a constrained spectrum. The allocated shaped pulses ( 120 ) are coherently converted into the respective frequency channels ( 54 ) and combined with the composite signal ( 58 ) to reduce an unwanted signal peak.