Patent ID: 9055529
Filing Date: 2015-06-09
Classification: H03F,H04B,H04W,Y02D

Abstract:
1. For use in a wireless communications network, a subscriber station comprising: a main processor configured to perform a plurality of functions to operate the subscriber station; a power source configured to provide power to one or more components in the subscriber station; and an envelope tracking power amplifier (ET PA) configured to amplify a signal, the ETPA configured to estimate and adaptively maintain time alignment between an envelope path and an RF path during operation of the ET PA, wherein the time alignment criterion is based on a mask performances comprising one of Evolved Universal Terrestrial Radio Access (EUTRA), UMTS Terrestrial Radio Access-1 (UTRA1), UMTS Terrestrial Radio Access-2 (UTRA2), and error vector magnitude (EVM) measurement, and wherein the ET PA estimates and adaptively maintains time alignment adaptive using a time-alignment process that includes non-iterative and iterative parts, wherein the Non-iterative part is an auto-correlation process used to determine a large time mismatch case to maximize the converging speed and the iterative part is used to determine smaller time mismatch case to achieve high resolution results.