基于CORDIC算法的改进的平方环设计

Design of modified squaring loop based on CORDIC algorithm

在数字通信中,载波恢复电路是非常重要的电路环节,而其中的平方环变换以其电路的简单受到了广泛的使用。为了进一步简化该电路结构,提出了一种改进的平方环电路,这种改进的平方环省去了2分频电路,同时在文章中作者进一步改进了这个电路,将其中的多个乘法器用CORDIC算法来实现,该算法仅使用移位运算与加法器,便于流水线结构实现,降低了电路的复杂特性。最后,将该改进的电路联合ISE14.7和Modelsim10.1a进行仿真,恢复出了输入信噪比分别为6 d B和80 d B下的载波信号,验证了该电路的可行性。

Carrier recovery is a very important part of the circuit in digital communication, and the squaring loop has been widely used for its simple circuit structure. To simplify the structure of the circuit further, a modified squaring loop circuit was proposed, which eliminates the need for two devided-frequency circuit. At the same time, we improve the circuit further by using CORDIC algorithm to realize a plurality of multipliers in this paper. The algorithm can be easily realized by pipelined architecture, and can reduce the complexity characteristic of the circuit, as this algorithm uses merely shift mathematical operation and adder. At the end, we unites ISE 14.7 with Modelsim 10.1a to go with the simulation of the modified circuit.Then we get the carrier signal of input SNR 6d B and 80 d B, respectively, which turns out to be feasible.