A Research About Fitting Method In Hardware With High Speed Performance And Its Implementation In FPGA

With the fast development of modern digital signal processing, indicators like speed,data amount and real-timing processing are becoming more significant in estimating the performance of calculation. Thus, methods in improving the speed and properties of calculation become a new research area in modern math and information processing technology. Calculation of software is not suitable in solving some complex calculation problems. In order to solve this problem, research on how to improve the speed of calculation in hardware is more meaningful.The fitting method of nonlinear functions is an important branch in digital signal processing. Fitting method is an efficient way in calculating some complex functions,which simplifies the calculation in hardware. By the advantages of flexibility,FPGA becomes easier in achievement of fitting method in hardware. With the fast development of VLSI,the technology of SoC is more mature. So combining the fitting method in calculating nonlinear functions with some SoCs which can solve some complex calculation problems is a good method in improving the capabilities of some systems.This is a good research direction in value of applications.With the purpose of solving the problems mentioned,this paper tries to design a hardware structure which can calculate some nonlinear functions by researching some fitting method. Then we put it on a SoC, which is designed for complex calculation. The main work of this paper is as follows:Firstly, researches are taken on fitting method algorithms in FPGA and comparison shows the differences in each algorithm. A good algorithm called piecewise nonlinear approximation method is used in dealing with the calculation of some nonlinear functions.Depending on the good performance in approximation accuracy,this method is suitable for some SoCs with complex calculation tasks.Secondly,a hardware structure of calculating some nonlinear functions is designed,which uses the algorithm of piecewise nonlinear approximation method. It can calculate many kinds of nonlinear functions, such as trigonometric function, Sigmoid function and anti-trigonometric function, which are widely used in modern digital signal processing.Experiments show that the calculation results achieve high accuracy, which is suitable for some SoCs with complex calculation tasks.Finally,the hardware structure of calculating some nonlinear functions is integrated on a target SoC, which is used for floating calculation. Some algorithms are achieved with the calculation of some nonlinear functions. Experiments prove that the hardware structure achieves good performance and is valuable in some applications.