Abstract: An amplification unit reduces a duty cycle of a digital signal at a carrier radio frequency to optimize the efficiency of the RF power amplifier that amplifies the reduced duty cycle signal. An exemplary amplification unit includes a duty cycle controller and a digital power amplifier. A delay unit in the duty cycle controller applies a delay to an input digital signal at the carrier radio frequency to generate a delayed signal at the carrier radio frequency. A logic gate in the duty cycle controller logically combines the input digital signal with the delayed signal to generate a modified digital signal at the carrier radio frequency, where the modified input digital signal has a reduced duty cycle relative to that of the input digital signal. Amplifying the modified digital signal in the digital RF power amplifier generates an amplified analog signal at the carrier radio frequency while improving amplifier efficiency.
Type:
Grant
Filed:
November 8, 2010
Date of Patent:
April 15, 2014
Assignee:
Ericsson Modems SA
Inventors:
Hendrik Visser, Roeland Heijna, Norbert Van Den Bos
Abstract: An OFDM modulation process and means for transmitting multiple carriers through a communication channel having a bandwidth arranged ion chunks with further subcarriers being allocated to form at least one guard band, comprising automatically and periodically shifting said chunks to the left or to the side in order to overlap said guard band and increase spectral diversity.
Abstract: The present invention relates to a method of suppressing noise in a communication device. The idea consists in forwarding to a noise suppression module some information regarding the radio transmission in terms of radio activity and/or in terms of radio transmission power. The module then advantageously uses this information to suppress radio path noise.