A TRANSMISSION METHOD TO COMBAT MULTIPLE CARRIER FREQUENCY OFFSETS (MCFOS) IN COORDINATED MULTIPLE POINT (COMP) SCHEMES

Abstract

In CoMP, two or multiple transmitters are coordinated to establish links with users. For example, a pair of coordinated base stations can transmit Alamouti-coded data, which has two streams, with one base station being responsible for one stream. When multiple carrier frequency offsets exist, the perfounance of Alamouti-type schemes in CoMP degrades seriously. MCFOs can exist when transmitters are not synchronized on the level of carrier generation, or can exist when the data streams face different Doppler situations caused by the movement of the users. Many works have been devoted to solving MCFOs for Alamouti-type signaling or space multiplexing. These techniques focus on the receiver algorithms, yet they work with limited success and usually are costly in implementation. We propose a transmission method which can facilitate a simple receiver to combat MCFOs. The receiver mainly uses a parallel ICI canceller to mitigate the effect of ICI. Simulation results of a system consisting of two cooperative transmitters with LDPC as the outer code are provided to illustrate our arguments.