Research Of Pilot-aided Channel Estimation In OFDM System

HEVC(Efficiency Video Coding High)as the latest generation of video coding standard,has excellent video compression performance to meet various application scenarios.With its outstanding encoding efficiency and network adaptability,the fields of application are very extensive,which brings more superior video experience.Though HEVC still adopts the traditional hybrid encoding framework,it has also introduced many new encoding technologies,which makes the encoding efficiency of the HEVC standard increased by about 50%compared with the last generation of video coding standard H.264/AVC.However,these technologies provide a better video encoding performance while also increase the complexity of encoding,which causes HEVC not suitable for the applications having high real-time requirements.Mode decision is an important module in the whole intra prediction encoding,and also is the main source of the complexity during intra prediction algorithm.In this paper,we study HEVC intra prediction encoding and focus on fast algorithm of its mode decision selection process.First,this paper introduces the basic principle of HEVC standard and describes the development of video encoding standards.Then researches on the whole process of HEVC encoding and its key encoding technologies,especially explains the structure of block partition and intra prediction encoding in detail.By analyzing HEVC intra mode decision algorithm,devised that it is the recursive block partition and RDO process lead to the high complexity of the algorithm.Secondly,a fast block partition based intra mode decision algorithm is proposed to for reducing the complexity of block partition.The algorithm is based on analyzing the complexity image,and makes encoding blocks having high complexity divided from a certain depth,and encoding blocks having low complexity terminated ahead of time to continue.Finally,considering the complexity of RDO process,a fast intra mode selection algorithm based on SATD is proposed.The algorithm retains RMD process and the RDO process while based on SATD to reduce the number of modes for cost RMD,thereby reduce encoding time.In official standard test platform HM16.0 realizes these two fast algorithms proposed in this paper,and the experimental results show that algorithms can maintain better encoding performance simultaneously save 16.30%and 13.14%encoding time respectively.