mmWave Demo Visualizer plot的疑问

谢谢你的解答，我还有两个疑问：

第一个图是visualizer显示截图，下图是我根据实时抓取的Data Port数据，经过计算后，用excel画出来的，形状是吻合的。我的疑问是：

1.虽然轮廓是吻合的，为什么抓取的数据画出的图比visualizer显示的图在Y轴方向会高大约5dB。

2.visualizer截图中x轴方向的m值是如何确定的，DataPort的数据是一维的，只有幅度信息，图中5m、10m的位置是如何确定的。

以下是Data Port输出的16进制数据值（the sum of log2 magnitudes of received antennas）：

0xde,0x77,0x3f,0x8b,0xb6,0x90,0xc4,0x89,0x26,0x89,0x90,0x8a,0x45,0x82,0x4e,0x76,
0x64,0x75,0x3f,0x71,0x8c,0x6b,0x08,0x6a,0x5e,0x65,0x02,0x6a,0x83,0x64,0x98,0x64,
0xd0,0x75,0x40,0x77,0xf9,0x6c,0x16,0x61,0x7c,0x58,0xad,0x5e,0xb4,0x61,0xbe,0x65,
0xd2,0x61,0x5d,0x69,0x53,0x6a,0x74,0x69,0x1e,0x67,0xd6,0x63,0xd6,0x5f,0xe4,0x60,
0xd0,0x66,0x28,0x66,0xaf,0x5f,0x7b,0x60,0x75,0x5e,0xc2,0x5f,0x90,0x5a,0x20,0x5d,
0x9c,0x59,0x31,0x62,0x69,0x60,0x40,0x63,0x7d,0x6c,0x1b,0x6e,0xd6,0x6d,0x4b,0x6d,
0xb3,0x7e,0x24,0x83,0x08,0x7d,0x10,0x72,0x6b,0x70,0x0f,0x6b,0xc5,0x67,0x8c,0x65,
0x40,0x67,0xeb,0x6b,0xa7,0x6b,0x35,0x70,0xee,0x70,0x52,0x66,0xdc,0x67,0xdd,0x67,
0xd7,0x73,0x98,0x72,0x4f,0x6a,0xde,0x69,0x05,0x68,0x0e,0x65,0x45,0x6f,0x99,0x72,
0x8c,0x74,0x1e,0x73,0x8d,0x6e,0x25,0x6f,0xa4,0x6e,0xc9,0x68,0xa7,0x6d,0xa4,0x74,
0x36,0x76,0xc6,0x70,0xb8,0x6a,0x23,0x6a,0xbf,0x67,0x1d,0x68,0xb1,0x71,0x3c,0x76,
0x97,0x72,0x9c,0x6f,0x49,0x6f,0x18,0x67,0x31,0x6b,0xb5,0x6b,0xc3,0x68,0xe5,0x6c,
0x5c,0x6a,0x2c,0x63,0xcc,0x5e,0xd8,0x65,0x67,0x66,0xe1,0x5f,0x3a,0x61,0x1e,0x61,
0x75,0x5c,0xec,0x5f,0x98,0x67,0xd2,0x65,0x42,0x70,0xd3,0x6e,0xd1,0x61,0x96,0x5c,
0x8e,0x5f,0x9c,0x5d,0xbc,0x5e,0x53,0x59,0x00,0x5c,0xb2,0x5b,0x47,0x5a,0x75,0x5a,
0xaa,0x5a,0xaf,0x59,0xce,0x5b,0x79,0x5b,0x94,0x5c,0xb3,0x5c,0x6d,0x5f,0xa6,0x5d,
0xb3,0x5d,0x81,0x5a,0x4a,0x59,0x67,0x59,0x61,0x5d,0x2f,0x5f,0x21,0x5a,0xb8,0x56,
0xb4,0x58,0x93,0x58,0x68,0x56,0x36,0x4f,0x59,0x54,0xf4,0x54,0x4d,0x54,0x19,0x52,
0x48,0x53,0xd5,0x57,0x33,0x56,0x7c,0x59,0x15,0x56,0x4c,0x54,0x04,0x54,0xcd,0x51,
0xec,0x4e,0xc2,0x58,0x07,0x5c,0x1c,0x57,0xbb,0x4e,0xf2,0x51,0xaa,0x51,0xe0,0x56,
0x63,0x57,0xe0,0x56,0x7c,0x53,0xb7,0x58,0xef,0x5a,0x53,0x50,0x0f,0x55,0xde,0x52,
0x9d,0x4d,0x10,0x4f,0xcc,0x51,0xbe,0x50,0xe0,0x4f,0x40,0x50,0x78,0x51,0xba,0x50,
0x41,0x50,0x03,0x51,0x55,0x4e,0x73,0x49,0xe3,0x4c,0xb8,0x4e,0x3e,0x4e,0xfc,0x4f,
0x71,0x50,0x0e,0x4f,0x42,0x4e,0x3a,0x51,0x52,0x4e,0x1b,0x4a,0x08,0x4d,0xb6,0x4c,
0xb2,0x49,0x1f,0x4a,0xb8,0x4e,0x0d,0x50,0x33,0x4c,0x6a,0x4f,0xf8,0x49,0x5f,0x4a,
0xe8,0x4d,0x95,0x4e,0x0d,0x50,0x79,0x4f,0x2c,0x4f,0x5d,0x4e,0xa2,0x4b,0x31,0x4a,
0xfc,0x46,0x3d,0x45,0x55,0x4b,0x92,0x42,0x62,0x4a,0xb5,0x4c,0x0e,0x4b,0x7e,0x4a,
0xf1,0x47,0xd2,0x46,0x9a,0x4a,0x5f,0x4c,0x10,0x43,0xa9,0x49,0x72,0x46,0x5e,0x47,
0x42,0x4a,0x81,0x47,0x31,0x44,0x38,0x47,0xe8,0x43,0x84,0x44,0xe0,0x46,0xe6,0x48,
0xe7,0x4b,0x46,0x47,0xd7,0x3e,0x60,0x3f,0xf8,0x40,0x37,0x38,0x74,0x42,0x29,0x42,
0xe2,0x3c,0x15,0x3e,0xee,0x3e,0x9e,0x39,0xd2,0x37,0x49,0x3a,0x9b,0x41,0x55,0x41,
0x0c,0x47,0xac,0x48,0xad,0x55,0x6b,0x5e,0x9a,0x5e,0x9e,0x5f,0x40,0x66,0x9d,0x68,

以下是我计算Relative Power（dB）的代码

char sample[512] = {
0xde,0x77,0x3f,0x8b,0xb6,0x90,0xc4,0x89,0x26,0x89,0x90,0x8a,0x45,0x82,0x4e,0x76,
0x64,0x75,0x3f,0x71,0x8c,0x6b,0x08,0x6a,0x5e,0x65,0x02,0x6a,0x83,0x64,0x98,0x64,
0xd0,0x75,0x40,0x77,0xf9,0x6c,0x16,0x61,0x7c,0x58,0xad,0x5e,0xb4,0x61,0xbe,0x65,
0xd2,0x61,0x5d,0x69,0x53,0x6a,0x74,0x69,0x1e,0x67,0xd6,0x63,0xd6,0x5f,0xe4,0x60,
0xd0,0x66,0x28,0x66,0xaf,0x5f,0x7b,0x60,0x75,0x5e,0xc2,0x5f,0x90,0x5a,0x20,0x5d,
0x9c,0x59,0x31,0x62,0x69,0x60,0x40,0x63,0x7d,0x6c,0x1b,0x6e,0xd6,0x6d,0x4b,0x6d,
0xb3,0x7e,0x24,0x83,0x08,0x7d,0x10,0x72,0x6b,0x70,0x0f,0x6b,0xc5,0x67,0x8c,0x65,
0x40,0x67,0xeb,0x6b,0xa7,0x6b,0x35,0x70,0xee,0x70,0x52,0x66,0xdc,0x67,0xdd,0x67,
0xd7,0x73,0x98,0x72,0x4f,0x6a,0xde,0x69,0x05,0x68,0x0e,0x65,0x45,0x6f,0x99,0x72,
0x8c,0x74,0x1e,0x73,0x8d,0x6e,0x25,0x6f,0xa4,0x6e,0xc9,0x68,0xa7,0x6d,0xa4,0x74,
0x36,0x76,0xc6,0x70,0xb8,0x6a,0x23,0x6a,0xbf,0x67,0x1d,0x68,0xb1,0x71,0x3c,0x76,
0x97,0x72,0x9c,0x6f,0x49,0x6f,0x18,0x67,0x31,0x6b,0xb5,0x6b,0xc3,0x68,0xe5,0x6c,
0x5c,0x6a,0x2c,0x63,0xcc,0x5e,0xd8,0x65,0x67,0x66,0xe1,0x5f,0x3a,0x61,0x1e,0x61,
0x75,0x5c,0xec,0x5f,0x98,0x67,0xd2,0x65,0x42,0x70,0xd3,0x6e,0xd1,0x61,0x96,0x5c,
0x8e,0x5f,0x9c,0x5d,0xbc,0x5e,0x53,0x59,0x00,0x5c,0xb2,0x5b,0x47,0x5a,0x75,0x5a,
0xaa,0x5a,0xaf,0x59,0xce,0x5b,0x79,0x5b,0x94,0x5c,0xb3,0x5c,0x6d,0x5f,0xa6,0x5d,
0xb3,0x5d,0x81,0x5a,0x4a,0x59,0x67,0x59,0x61,0x5d,0x2f,0x5f,0x21,0x5a,0xb8,0x56,
0xb4,0x58,0x93,0x58,0x68,0x56,0x36,0x4f,0x59,0x54,0xf4,0x54,0x4d,0x54,0x19,0x52,
0x48,0x53,0xd5,0x57,0x33,0x56,0x7c,0x59,0x15,0x56,0x4c,0x54,0x04,0x54,0xcd,0x51,
0xec,0x4e,0xc2,0x58,0x07,0x5c,0x1c,0x57,0xbb,0x4e,0xf2,0x51,0xaa,0x51,0xe0,0x56,
0x63,0x57,0xe0,0x56,0x7c,0x53,0xb7,0x58,0xef,0x5a,0x53,0x50,0x0f,0x55,0xde,0x52,
0x9d,0x4d,0x10,0x4f,0xcc,0x51,0xbe,0x50,0xe0,0x4f,0x40,0x50,0x78,0x51,0xba,0x50,
0x41,0x50,0x03,0x51,0x55,0x4e,0x73,0x49,0xe3,0x4c,0xb8,0x4e,0x3e,0x4e,0xfc,0x4f,
0x71,0x50,0x0e,0x4f,0x42,0x4e,0x3a,0x51,0x52,0x4e,0x1b,0x4a,0x08,0x4d,0xb6,0x4c,
0xb2,0x49,0x1f,0x4a,0xb8,0x4e,0x0d,0x50,0x33,0x4c,0x6a,0x4f,0xf8,0x49,0x5f,0x4a,
0xe8,0x4d,0x95,0x4e,0x0d,0x50,0x79,0x4f,0x2c,0x4f,0x5d,0x4e,0xa2,0x4b,0x31,0x4a,
0xfc,0x46,0x3d,0x45,0x55,0x4b,0x92,0x42,0x62,0x4a,0xb5,0x4c,0x0e,0x4b,0x7e,0x4a,
0xf1,0x47,0xd2,0x46,0x9a,0x4a,0x5f,0x4c,0x10,0x43,0xa9,0x49,0x72,0x46,0x5e,0x47,
0x42,0x4a,0x81,0x47,0x31,0x44,0x38,0x47,0xe8,0x43,0x84,0x44,0xe0,0x46,0xe6,0x48,
0xe7,0x4b,0x46,0x47,0xd7,0x3e,0x60,0x3f,0xf8,0x40,0x37,0x38,0x74,0x42,0x29,0x42,
0xe2,0x3c,0x15,0x3e,0xee,0x3e,0x9e,0x39,0xd2,0x37,0x49,0x3a,0x9b,0x41,0x55,0x41,
0x0c,0x47,0xac,0x48,0xad,0x55,0x6b,0x5e,0x9a,0x5e,0x9e,0x5f,0x40,0x66,0x9d,0x68,};  

const double Q8_Weight[16]={128.0,64.0,32.0,16.0,8.0,4.0,2.0,1.0,1.0/2,1.0/4,1.0/8,1.0/16,1.0/32,1.0/64,1.0/128,1.0/256};
double Q8toFloat(uint16_t Qformat)
{
	  double a = 0.0;
	  int i;
	  for(i=0; i<16; i++)
	  {
	  	  if((0x8000>>i)&Qformat)  	
	  	  {  	
	  	      a += Q8_Weight[i];
	  	  }
	  }
	  return a;
}

{
    for(i=0; i<512;i=i+2)
    {
    	  f = Q8toFloat(*(uint16_t*)&sample[i]);
    	  f = f/4;//four antennas
    	  f = f*log10(2)/log10(10);//log2 to log10
    	  f = f*10;//dB:10log10
    	  printf("%.9f\n",f);    
    }
}