CVSD的算法、仿真及实现

The Algorithm,Simulation and Realization of CVSD

译码中的低通滤波器采用汉宁窗实现,是因为它具有较窄的主瓣和较小的最大旁瓣。通过分析连续可变斜率增量调制(CVSD)的编译码工作原理,提出了CVSD的软件算法,并画出了编译码仿真软件流程图。同时权衡各种参数的影响,合理选取了各参数的值,用MATLAB对CVSD软件算法进行仿真。结果表明:量阶δ能够自动地随输入信号平均斜率的大小而连续变化,译码输出信号实现了对输入信号的理想逼近,最后在可编程逻辑器件(FPGA)中实现了CVSD调制功能。

Because of the poor currency,agility and expansibility of specific CVSDs,it is necessary to realize CVSD on FPGA.Through analyzing the codedecode principle of CVSD,the CVSD algorithm is proposed and the codedecode simulation flow charts are drawn.Due to the preferable character of Hanning window,the lowpass filter adopts the Hanning window and its simulation of the algorithm in MATLAB.In according with the result of the simulation,we know that the quantified phase continuously changes with the mean value of the slope in the signal,which ideally approaches to the input signal.At last,CVSD is implemented in FPGA.