The Research Of Synchronization And Channel Estimation Algorithms In IEEE802.11ad System

With the rapid development of the information society, wireless data grows fast, so people's requirements of wireless communication system are getting higher and higher, the research of the transmission rate develops from the initial Kbit/s to Mbit/s and so far Gbit/s.60GHz communication system can improve the transmission rate to gigabits at extremely low signal-to-noise ratio. It has many characteristics such as high speed, good confidentiality and ease of integration, and is one of the most potential wireless communication technologies. As an important wireless communication standard working in the 60 GHz band, IEEE 802.11ad has been widely supported by the industry and has bright market prospects in short-range high-speed wireless communication.Synchronization and channel estimation are one of the key technologies of wireless communication systems. In this thesis, the synchronization and channel estimation algorithms are studied under the frame structure defined by IEEE 802.11ad protocol. A variety of synchronization and channel estimation algorithms are implemented and compared, and the system implementation scheme of the receiver is proposed. According to the 802.11ad protocol, the simulation platform is established and the algorithm is implemented, then the performance of the receiver is analyzed. Among them, the main contributions and innovations include:Firstly, this thesis studies the commonly used time synchronization algorithms, then designs the time synchronization scheme based on IEEE802.11 ad standard, and proposes a time fine synchronization algorithm based on differential sliding correlation. The system simulation results show that the proposed algorithm has high accuracy, good ability to resist frequency offset and noises ,and meets the system performance requirements in multipath fading environment.Secondly, this thesis studies the commonly used frequency synchronization algorithms, and proposes an improved linear regression frequency offset estimation algorithm. The proposed algorithm can effectively resist noise and multipath interference by making the phase jump at a fixed place and performing a linear fit between the two trip points to avoide the use of the splice function.Thirdly, according to the characteristics of received signal preamble,this thesis realizes the channel estimation algorithm based on Golay sequence autocorrelation and performs performance analysis under different channel models. Finally, based on the above research, this thesis puts forward the scheme of the receiver in the system, and builds the simulation platform according to the 802.11ad protocol. Artificially adding various synchronization deviation, the system receiving scheme is studied under different channel models, and the whole performance analysis of the system is completed.The receiving scheme designed in this thesis can support both SC and OFDM standard mode, so that the hardware implementation can be more effective.