Abstract: The present invention provides a method for despreading spread signal used in a receiver of a wireless communication system, comprising the steps of: preprocessing spread signal to derive a group of spreading chips corresponding to a data symbol; processing Hie spreading chips to extract cophase components and orthogonal components of each of the spreading chips; and converting and combining the group of cophase components and orthogonal components according to a preset selecting signal to derive a group of despreading chips.

Abstract: New biodegradable polyanhydrides are disclosed, which are prepared by homopolymerization of dimer of bile acid, especially lithocholic acid, or bycopolymerization with linear dicarboxylic acid, especially sebacic acid. These biodegradable polyanhydrides have degradation kinetics and a release rate that make them particularly useful for controlled drug release. More specifically, the degradation kinetics of such anhydrides and the release rate of molecules embedded therein make them useful as matrices for controlled drug release systems. The rates of degradation and release can be adjusted by the copolymer composition. The near zero-order kinetrics of release of the drug embedded in the matrices made of such anhydrides, make the same particularly useful since they can deliver an active ingredient at a constant rate for long period of time, avoiding the inauspicious saw-tooth pattern of conventional systemic administration.