Patent ID: 8208457

Claim:
A symbol-level adaptation method to adapt at least one coefficient of an equalizer, the equalizer being used in an orthogonal CDMA (Code Division Multiple Access) receiver to correct channel distortions at chip level, the receiver simultaneously receiving a pilot channel spread with a full pilot channelization code and other channels spread with respective channelization codes, each channelization code being orthogonal to any other simultaneously used channelization codes, wherein the method comprises the steps of: a) determining if there exists a shortened pilot channelization code which has a spreading factor shorter than the spreading factor of the full pilot channelization code and which is, at the same time, still orthogonal to any other simultaneously active channelization codes, a channelization code being “active” if the power of the signal despread with this channelization code is higher than a predetermined threshold, and, b) if there exists a shortened pilot channelization code, despreading the pilot channel using the shortened pilot channelization code to obtain a pilot symbol estimation, or in the absence of such a code, despreading the pilot channel using the full pilot channelization code to obtain the pilot symbol estimation, and c) adapting the value of the equalizer coefficient according to the error between the pilot symbol estimation obtained from step b) and a corresponding expected pilot symbol.