The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 23, 2003
Filed:
Sep. 30, 1999
Eric A. Shull, Raleigh, NC (US);
Robert A. Zak, Apex, NC (US);
Ericsson Inc., Research Triangle Park, NC (US);
Abstract
An artificial ramping waveform profile is applied to a burst transmission power amplifier in order to reduce transients. A profile source is supplied with a plurality of pre-determined artificial ramping profiles. At the beginning of the burst transmission ramping period, one of the artificial ramping profiles is selected and fed to the power amplifier. The selection of the artificial ramping profile is based at least in part on the first message symbol of the message to be burst transmitted. Preferably, each different possible first message symbol has its own unique corresponding artificial ramping profile, and the corresponding waveform is used to artificially ramp the power amplifier when that message symbol is the first message symbol. At the end of the ramping period, the inputs to the power amplifier are switched to the traditional signal source, such as the FIR filters, etc., for receipt of the message symbols. The transmitted signal is based then on the response of the power amplifier to the artificial ramping profile and the message symbols. The generation of transient adjacent channel power is significantly reduced by artificially ramping the power amplifier rather than allowing for natural ramping. By choosing the artificial ramping profile based on the first message symbol, the phase trajectory changes near the end of the ramping period may be significantly smoothed, thereby lessening the generation of undesired harmonic power levels.