Research On Hybrid-arq In LTE-A Downlink

As a communication standard in the future by 3GPP, LTE-A has become the focus of Chinese telecommunication industry. HARQ which can reduce errors and improve the reliability of transmission is the key problem of LTE-A, so it has good practical significance to research on HARQ in LTE-A.In this thesis, through researching on LTE-A and the principles, techniques and processes of HARQ, the structures of HARQ for LTE-A downlink simulation platform is built. By using the platform, HARQ technique is simulated and evaluated to analysis the effect of reducing of BLER.Then, by analyzing the basic principles of Hamming codes, an improved scheme based on Hamming distance is proposed. Simulation results show that the scheme can effectively improve the accuracy of transmission.Finally, to improve Turbo decoding scheme on the receiver in LTE-A, an improved scheme based on rate matching is proposed. The simulation results show that the new scheme can effectively reduce the number of iterations in Turbo decoding. Thereby, it can reduce the amount of system operation and can be applied to LTE-A downlink.