摘要：The Third Generation Partnership Project (3GPP) initially defined Release-8 as the first standard of the Long Term Evolution (LTE), a novel high-speed all-IP wireless access technology for mobile communication system using OFDMA and MIMO as native technologies. However, even this high-speed technology was found incapable of meeting true IMT-Advanced 4G requirements. As such, Release-10 Release- 11 and Release-12, which is known as LTE-Advanced, was released to achieve this target with further improvements while maintaining backward compatibility with Release-8. The main contribution of this paper is to undergo some thorough research on the key technologies of the adaptive LTE-A system based on 3GPP LTE-A physical layer specifications, and then give the adaptive system performance simulation and analysis. Specifically, in the design scheme of the adaptive LTE-A system, more research about adaptive modulation and coding has been given, which includes a new rate matching algorithm based on circularly selecting and interlaced puncturing as well as a different antenna mechanism based on adaptive scheduling solution in order to enhance the system performance. Simulation results indicate that the system with the improved adaptive schemes has better performance which could also prove the design of the adaptive system is accurate and reasonable.
