Patent ID: 6717934
Filing Date: 2004-04-06
Classification: H04L

Abstract:
A method for operating a wireless mobile station to receive a time slot sent through a radio channel from a transmitter, the time slot having a first portion and a second portion, said first portion containing information for specifying whether said second portion is modulated using a first modulation type or a second modulation type, wherein when modulated using said second modulation type said second portion comprises at least one predetermined symbol sequence at a predetermined location, comprising steps of:receiving the time slot; operating a demodulator for use with the second type of modulation and determining an amount of detected signal energy, assuming the predetermined symbol sequence being located at the predetermined symbol sequence location; comparing the power of a detection error to a threshold value to derive a modulation type indication; and based at least in part on the modulation type indication, specifying that said second portion of the received time slot is modulated with the first modulation type or that said second portion is modulated with the second modulation type.