Hybrid coordinated strategy of downlink coordinated multi-point transmission

Coordinated multi-point(CoMP) transmission is put forward in the long term evolution-advanced(LTE-A) system to improve both average and cell-edge throughput. CoMP-joint processing(JP) scheme can get a larger cell-edge throughput and a lower bit error rate(BER) than the CoMP-coordinated beamforming(CB) scheme, but it also has higher complexity due to data sharing. A hybrid coordinated strategy with parameter α, which indicates the proportion of users employing the CoMP-JP scheme,is proposed to apply the CoMP-JP scheme to improve the poorer communication quality of cell edge and employ the CoMP-CB scheme for other users to enhance average throughput and spectral efficiency. This paradigm selects users defined by the certain threshold of signal to interference plus noise power ratio(SINR)corresponding to the parameter α to the CoMP-JP scheme. This paper compares the BER performance between the block diagonalization(BD) based precoding and the linear precoders by maximizing signal to leakage and noise ratio(SLNR), and also indicates that the SLNR based precoding algorithm gets lower BER than the BD based precoding algorithm with certain signal-to-noise ratios(SNRs). Finally, this paper discusses that the system performance is partially affected by the percentage of CoMP-JP users and concludes that 50% of users sorted to communicate under the CoMP-JP scheme will reach the best system performance.