基于CORDIC算法的通用调制器设计

Design of General Modulator Based on CORDIC Algorithm

介绍了基于CORDIC算法通用调制器的设计与实现。该方法能同时完成调频、调幅和调相的功能。可以解决基于查找表的DDS实现通用调制器占用FPGA中的乘法器和大量的ROM资源的问题。CORDIC算法是实现快速精确计算正、余弦函数值的主要方法,在工程实际中有着广泛的应用;而传统的查找表或差值法计算,在精度、运算速度方面不能兼得,且占用资源多。文中提出了基于CORDIC算法的通用调制器的实现方法,使用VHDL硬件描述语言进行编程实现,在ISE12.4中对算法进行功能仿真,最后通过Xilinx公司的FPGA Spartan-3系列XC3S50芯片进行了具体验证。结果表明,该实现方案不仅计算速度快,而且硬件资源消耗少,显著地提高了算法精度。

The design and implementation of general modulator based on the CORDIC algorithm is introduced. The method can also complete the AM, FM and PM function. The shortcoming such as occupying FPGA a lot of resources of ROM, can be overcoming. CORDIC （ Coordinate Rotation Digital Computer） algorithm is the main method to realize the fast and accurate trigonometric function ,and is widely used in modem engineering. With the traditional looking up table or differential methods, the calculation accuracy and speed cannot be got at the same time, taking up more resources. The CORDIC algorithm is proposed in this paper to design and implement the general modulator, using VHDL to program by ISE 12.4, and the function simulation can be got. Finally, the implementation on the Xilinx FPGA chips and the algorithm is tested. The result indicates that the optimized realization calculates faster than the traditional looking up table, and use less resources, improving the algorithm accuracy significantly.