Research On The Joint Processing Technology In Coordinated Multipoint Transmission

In cellular communication system, the time delay difference and interference have agreat effect on the performance of the transmission system, especially for the cell-edge users,which can affect the communication system transmission quality. Coordinated multipointjoint processing can reduce time delay difference and interference.We first study the transmission scheme for the coordinated multipoint joint processingsystem. Five different transmission schemes, such as Single Frequency Network, Phase ShiftDiversity, Space Frequency Block Code, Global Precoding and Phase Correction Precoding,are presented for comparative analysis. A two stage phase correction precoding transmissionscheme is proposed, which can decrease the time delay difference for the transmission link.Simulation shows that the proposed algorithm can basically eliminate the influence of thetime delay difference on the system performance and can make the BER decreases at almost2dB.Then, we study the interference alignment in downlink multi-user joint processingscenario. A new precoding algorithm for multi-user joint processing based on interferencealignment is proposed, which can suppress the interference from the neighbor collaborativearea BS and can eliminate all inter-user interference. Compared to the conventional linear BDprecoding scheme, the probility of total bit error decreases one order of magnitude and thesum–rate of the whole system has increased at almost two times at the SNR=30dB in theproposed interference alignment multi-user joint processing transmission scheme.