Subcarrier multiplexing in LTE-COMP OFDMA

Coordinated Multipoint (CoMP) transmission is seen as a valuable tool in LTE-Advanced to improve cell-edge and/or system throughput. CoMP is divided into two categories; Joint Transmission (JT) and Coordinated Scheduling/Beamforming (CS/CB). In JT, backhaul data and channel information intended for a user are shared among coordinating base station (CBS) whereas in CS/CB, data is only transmitted from one CBS, however scheduling and beamforming are coordinated to reduce the effect of co-channel interference (CCI). This paper introduces a novel subcarrier multiplexing scheme which aims to exploit the extra degrees of freedom provided by CoMP systems based on the principles of superposition coding. Multiple streams from coordinating femtocell access points (CFAP) are superimposed together such that they produce a unique interference pattern known at the receiver which is equipped with a single antenna. Simulation results show that we get an increase in data rate according to the number of CFAP. The proposed scheme also provides better bit error rates compared to traditional schemes, with minimal overhead signalling and without the need for channel estimation at receiver.