A、fc-f1=f2-fc
B、f2-f1=fc
C、f2+f1=fc
D、f1·f2=fc
喵查答案：fc-f1=f2-fc
When FSK modulation is performed on a signal, and if the carrier frequency is fc and the original/modulated signal frequencies are f1 and f2 respectively (f1 < f2), what is the relationship between the three?
-
Generally speaking, the higher the sound quality is required, the higher the quantization level and the lower the sampling frequency is. -
The higher the sampling frequency, the closer the discrete digitized sound wave is to its original waveform. -
Audio files in WAV format do not use compression algorithm, so they have good sound restorability, strong stereoscopic impression and relatively large file capacity. -
MPEG video compression standards include MPEG-1, MPEG-2, MPEG-4, MPEG-7 and MPEG-21.
- 定义如下变量和数组： int k; int a[3][3]={1,2,3,4,5,6,7,8,9}; 则下面语句的输出结果是________。 for(k=0;k<3;k++) printf("%d ",a[k][2-k]);
- 下面程序的运行结果是________int main(){ int a[6],i; for(i=1;i3))%5; printf(“%2d”,a[i]); } return 0;}
- 定义如下的变量和数组int i;int y[2][3]={2,4,6,8,10,12}则下面语句输出结果for(i=0;i<2;i++)printf("%d ",y[1-i][i+1]);
- 以下程序段给数组所有的元素的输入数据，请选择正确的答案#includemain(){float x[5],m=0;while(m<5)scanf(“%.2f”,______);}
- 要求下面的程序运行后，显示如下结果：2 10 4 61 5 2 32 4 7 85 1 3 2则程序中的划线处应填入________.#include void main( ){ int a[4][4]={ ________ }; int i,j; for(i=0;i<4;i++) {for(j=0;j<4;j++) printf("%4d",a[i][j]); printf("\n"); }
- 执行下面的程序段后,变量a中的值为int a=3, s[5]={1};s[0]=a; a=s[2]*10;
- 执行下面的程序段后,变量a中的值为int a=3, s[5]={1,2};s[0]=a; a=s[2]*10;
- 下列程序执行后的输出结果是int a[3][3]={1,2,3,4,5,6,7,8,9};printf(“%d \n”,a[1][2]);