Inventors

Yong Su Lee, Kim Jun-Woo, 박윤옥, Bang Young Jo

Application No.

11791442 (2005.06.24)

Publication No.

20080056394 (2008.03.06)

Registration No.

7746966 (2010.06.29)

Country

UNITED STATES

Abstract

The present invention relates to a method for automatic gain control (AGC) before an initial synchronization of a mobile station modem in OFDM system, and an apparatus thereof. The AGC apparatus includes: an initial synchronization inspector that verifies whether an initial synchronization for an input block sample (k) signal has been performed; a frame divider that divides a frame into predetermined intervals B(k) for the input block sample(k) signal in the case that the initial synchronization has not been performed; a reference value inspector that compares a difference value Pref Pcalc, between a predetermined reference value Pref and sample data average energy Pcalc, with a predetermined value; a count controller that increases or decreases the count when the difference value Pref Pcalc compared by the reference value inspector is greater or less than the predetermined value; a count inspector that inspects whether the count is greater or less than 0 when the input block sample (k) reaches a maximum value MAX; and a gain controller which increases or decreases the gain, level by level, according to the count inspection result of the count inspector.