Research And Implementataion Of Synchronization Algorithms Based On802.11ac Protocol

With the increasing demand of wireless communications, the number of mobile terminals is fast growing and the wireless trend is invincibly. The 5G Wi-Fi(the fifth Generation WIreless-FIdelity) which can satisfy higher throughput is pressing forward at this right moment. However, the development is limited to the complexity of the algorithm and the consumption of hardware resources, which leads the 5G Wi-Fi not widely used. Meanwhile, during the process of implementation, the existing algorithms use either by increasing the cost of time or additional hardware resources to ensure the performance of the algorithm. Besides, synchronization is the precondition of any communication system.This thesis proposes several improved algorithms in order to solve the problems of existing algorithms, in order to achieve the implementation of synchronization. Then this thesis analyses the characteristics of communication systems based on IEEE802.11 ac protocols in detail,provides and simulates the four core modules.The core modules are frame detection, rough frequency synchronization, symbol synchronization and fine frequency synchronization modules. The improved algorithms are given as follows, the first one proposes a frame detection union impulse normalization algorithm dealing with the large range of peak value of impulse change with SNR, with the output of frame detector to normalize the output of symbol synchronization,in order to make the range of peak value of symbol synchronization decrease to the best possible minimum range; the second one proposes a delay adding impulse detection algorithm aimed at the problem of impulse detection’s difficulty of multiple antenna systems, with the method of delay adder to make the two fuzzy impluses to one determined impluse, in order to make the probability of correctly detection of the impulse increased to the best possible highest value;the third one proposes a low-complexity co-correlation algorithm in allusion to the hardware consumption, with the method of quantifying the long training sequence to be the nearest value of integer power of 2 to achieve using a single shift to implement a multiplier,in order to make the multiplier core to the least. After that, the analysis of performance index of the whole IEEE802.11 acbaseband system is carried out. Lastly, the improved synchronization algorithm is achieved in the hardware platform with FPGA utilized.The simulation results show that the maximum error of frame detection and the maximum residual frequency deviation are lower than the necessarymaximum error value,and the probability of correct and false detection of symbol synchronization can be idealat appropriate SNR. On the other hand,the resource of the FPGA(XC7K325T) adopted in the synchronization algorithmcosts can fully meet the needsand requirements of implementation together with digital down conversion(DDC) in one single chip, and the hardware resource consumption is within half chip. Above all, the indicators can meet the expected requirements.