Abstract: This paper proposed two novel precoding schemes to maximize the system sum-rate under the constraint of Specific Absorption Rate(SAR) for MIMO uplink system．These schemes not only maximize the system spectral efficiency,but also take the SAR impact on the transmit power into account．This paper brought the SAR constraint into system resource optimization early so as to reduce the burden introduced by SAR measurement and test work．Simulation results show that these schemes could fulfill the SAR under the limit,meanwhile greatly improve system perfor-mance．

Key words: MIMO,SAR,Precoding