Zhang Chaozhu, Han Jinan, Li Ke
College of Information and Communication Engineering, Harbin Engineering University, Harbin 150001, China.
ScientificWorldJournal. 2014;2014:897381. doi: 10.1155/2014/897381. Epub 2014 Jul 7.
The numerical controlled oscillator has wide application in radar, digital receiver, and software radio system. Firstly, this paper introduces the traditional CORDIC algorithm. Then in order to improve computing speed and save resources, this paper proposes a kind of hybrid CORDIC algorithm based on phase rotation estimation applied in numerical controlled oscillator (NCO). Through estimating the direction of part phase rotation, the algorithm reduces part phase rotation and add-subtract unit, so that it decreases delay. Furthermore, the paper simulates and implements the numerical controlled oscillator by Quartus II software and Modelsim software. Finally, simulation results indicate that the improvement over traditional CORDIC algorithm is achieved in terms of ease of computation, resource utilization, and computing speed/delay while maintaining the precision. It is suitable for high speed and precision digital modulation and demodulation.
数控振荡器在雷达、数字接收机和软件无线电系统中有着广泛的应用。首先,本文介绍了传统的CORDIC算法。然后,为了提高计算速度并节省资源,本文提出了一种应用于数控振荡器(NCO)的基于相位旋转估计的混合CORDIC算法。该算法通过估计部分相位旋转方向,减少了部分相位旋转和加减法单元,从而降低了延迟。此外,本文利用Quartus II软件和Modelsim软件对数控振荡器进行了仿真和实现。最后,仿真结果表明,该算法在保持精度的同时,在计算简便性、资源利用率和计算速度/延迟方面优于传统的CORDIC算法。它适用于高速高精度的数字调制和解调。