/// <summary>
/// 计算时域信号的复数频谱，包含幅度谱和相位谱信息
/// </summary>
/// <param name="waveform">时域波形数据</param>
/// <param name="windowType">窗类型</param>
/// <param name="spectrum">计算后的复数频谱数据</param>
public static void AdvanceComplexFFT(double[] waveform, WindowType windowType, ref Complex[] spectrum)
{
if (waveform == null || spectrum == null || spectrum.Length < (waveform.Length / 2 + 1))
{
throw new JYDSPUserBufferException();
}
int n = waveform.Length, windowsize = waveform.Length; //做FFT的次数
int fftsize = windowsize; //做FFT点数
double cg = 0, enbw = 0;
double[] xInTmp = null;
double[] windowData = null;
xInTmp = new double[fftsize];
GCHandle gchXIn = GCHandle.Alloc(waveform, GCHandleType.Pinned);
var xInPtr = gchXIn.AddrOfPinnedObject();
GCHandle gchXout = GCHandle.Alloc(spectrum, GCHandleType.Pinned);
var xOutPtr = gchXout.AddrOfPinnedObject();
try
{
//生成窗函数的数据
windowData = new double[windowsize];
Window.GetWindow(windowType, ref windowData, out cg, out enbw);
CBLASNative.cblas_dscal(windowsize, 1 / cg, windowData, 1); //窗系数归一化
CBLASNative.cblas_dscal(spectrum.Length, 0, xOutPtr, 1); //将xOut清零
/*TIME_DOMAIN_WINDOWS(windowType, x_in, &CG, &ENBW, windowsize);*//*(double*)(xIn + i * windowsize)*/
VMLNative.vdMul(windowsize, windowData, xInPtr, xInTmp);
BasicFFT.RealFFT(xInTmp, ref spectrum);
}
finally
{
gchXIn.Free();
gchXout.Free();
}
}
/// <summary>
/// 频谱单位转换函数
/// </summary>
/// <param name="spectrum">输入频谱，单位转换后返回的序列也保存在里面</param>
/// <param name="spectrumType">输入频谱类型，功率谱或者幅度谱</param>
/// <param name="df">频谱间隔</param>
/// <param name="unitSetting">单位转换设置</param>
/// <param name="equivalentNoiseBw">计算频谱时，加窗所用窗函数的等效噪声带宽</param>
/// <returns></returns>
private static void UnitConversion(double[] spectrum, double df, SpectrumType spectrumType,
UnitConvSetting unitSetting, double equivalentNoiseBw)
{
double scale = 1.0;
int freq0Idx = 0, N = spectrum.Length;
//VMLNative.vdSqr(N, spectrum, spectrum);
if (unitSetting.PeakScaling == PeakScaling.Peak) //峰峰值要乘以2
{
switch (spectrumType)
{
case SpectrumType.Amplitude: // Sqrt2
scale *= Sqrt2;
break;
case SpectrumType.Power: // 2
scale *= 2;
break;
default:
throw new ArgumentOutOfRangeException(nameof(spectrumType), spectrumType, null);
}
CBLASNative.cblas_dscal(N, scale, spectrum, 1);
spectrum[0] /= scale; //零频不用
}
//根据设置的转换单位进行转换
switch (unitSetting.Unit)
{
case SpectrumUnits.V:
{
if (SpectrumType.Power == spectrumType)
{
VMLNative.vdSqrt(N, spectrum, spectrum);
}
break;
}
case SpectrumUnits.dBV:
{
if (SpectrumType.Power == spectrumType)
{
VMLNative.vdSqrt(N, spectrum, spectrum);
}
//lg
VMLNative.vdLog10(N, spectrum, spectrum);
scale = 20;
//20*lg
CBLASNative.cblas_dscal(N, scale, spectrum, 1);
break;
}
case SpectrumUnits.dBmV:
{
if (SpectrumType.Power == spectrumType)
{
VMLNative.vdSqrt(N, spectrum, spectrum);
}
CBLASNative.cblas_dscal(N, 1e3, spectrum, 1); //V To mV
VMLNative.vdLog10(N, spectrum, spectrum); //To Lg
scale = 20;
CBLASNative.cblas_dscal(N, scale, spectrum, 1); //To 20*Lg
break;
}
case SpectrumUnits.dBuV:
{
if (SpectrumType.Power == spectrumType)
{
VMLNative.vdSqrt(N, spectrum, spectrum);
}
CBLASNative.cblas_dscal(N, 1e6, spectrum, 1); //V To uV
VMLNative.vdLog10(N, spectrum, spectrum); //To Lg
scale = 20;
CBLASNative.cblas_dscal(N, scale, spectrum, 1); //To 20*Lg
break;
}
case SpectrumUnits.V2:
{
if (SpectrumType.Amplitude == spectrumType)
{
VMLNative.vdSqr(N, spectrum, spectrum);
}
break;
}
case SpectrumUnits.W:
case SpectrumUnits.dBW:
case SpectrumUnits.dBm:
{
if (SpectrumType.Amplitude == spectrumType)
{
VMLNative.vdSqr(N, spectrum, spectrum);
}
scale = 1.0 / unitSetting.Impedance; //1/R
CBLASNative.cblas_dscal(N, scale, spectrum, 1); //W = V^2/R
if (unitSetting.Unit == SpectrumUnits.dBW) //dBW = 20lgW
{
//lg
VMLNative.vdLog10(N, spectrum, spectrum);
scale = 20;
//20*lg
CBLASNative.cblas_dscal(N, scale, spectrum, 1);
}
else if (unitSetting.Unit == SpectrumUnits.dBm) // dBm = 10lg(W/1mW)
{
CBLASNative.cblas_dscal(N, 1e3, spectrum, 1); // W/1mW
//lg
VMLNative.vdLog10(N, spectrum, spectrum);
scale = 10;
//10*lg
CBLASNative.cblas_dscal(N, scale, spectrum, 1);
}
break;
}
default:
{
break;
}
}
if (!unitSetting.PSD)
{
return;
}
//谱密度计算
scale = 1.0 / (equivalentNoiseBw * df);
CBLASNative.cblas_dscal(N, scale, spectrum, 1);
}
/// <summary>
/// 计算时域信号的复数频谱，包含幅度谱和相位谱信息
/// </summary>
/// <param name="waveform">时域波形数据</param>
/// <param name="spectralLines">频谱线的条数</param>
/// <param name="windowType">窗类型</param>
/// <param name="spectrum">计算后的复数频谱数据</param>
/// <param name="spectralInfo">返回的频谱数据的参数信息</param>
public static void AdvanceComplexFFT(double[] waveform, int spectralLines, WindowType windowType,
double[] spectrum, ref SpectralInfo spectralInfo)
{
int n = waveform.Length, windowsize = 0, fftcnt = 0; //做FFT的次数
int fftsize = 0; //做FFT点数
double cg = 0, enbw = 0, scale = 0.0;
double[] xInTmp = null;
double[] windowData = null;
Complex[] xOutCTmp = null;
//输入的线数超过最大支持的线数则使用最大支持线数
if (spectralLines > MaxSpectralLine)
{
spectralLines = MaxSpectralLine;
}
//输入的点数小于线数，则窗长度为N，先加窗再补零到2*spectralLines再做FFT
if (n <= 2 * spectralLines)
{
windowsize = n;
fftcnt = 1;
}
else
{
windowsize = 2 * spectralLines;
fftcnt = n / (2 * spectralLines);
}
fftsize = 2 * spectralLines; //不管N与2*spectralLines的关系是怎么样，FFT的点数都应该为 2*spectralLines
xInTmp = new double[fftsize];
xOutCTmp = new Complex[fftsize / 2 + 1];
if (n < (2 * spectralLines))
{
//memset(x_in + N, 0, (fftsize - N) * sizeof(double)); //补零至spectralLines
for (int i = n; i < fftsize; i++)
{
xInTmp[i] = 0;
}
}
//memset(xOut, 0, spectralLines * sizeof(double));
//生成窗函数的数据
windowData = new double[windowsize];
Window.GetWindow(windowType, ref windowData, out cg, out enbw);
CBLASNative.cblas_dscal(windowsize, 1 / cg, windowData, 1); //窗系数归一化
CBLASNative.cblas_dscal(spectrum.Length, 0, spectrum, 1); //将xOut清零
GCHandle gch = GCHandle.Alloc(waveform, GCHandleType.Pinned);
var xInPtr = gch.AddrOfPinnedObject();
for (int i = 0; i < fftcnt; i++)
{
//拷贝数据到临时内存中
//memcpy(x_in, x + i * windowsize, fftsize * sizeof(double));
/*TIME_DOMAIN_WINDOWS(windowType, x_in, &CG, &ENBW, windowsize);*//*(double*)(xIn + i * windowsize)*/
VMLNative.vdMul(windowsize, windowData, xInPtr + i * fftsize * sizeof(double), xInTmp);
BasicFFT.RealFFT(xInTmp, ref xOutCTmp);
//计算FFT结果复数的模,复用x_in做中间存储
VMLNative.vzAbs(fftsize / 2 + 1, xOutCTmp, xInTmp);
//每次计算结果累加起来
VMLNative.vdAdd(spectralLines, xInTmp, spectrum, spectrum);
}
scale = 2 * (1.0 / fftcnt) / Sqrt2; //双边到单边有一个二倍关系,输出为Vrms要除以根号2
//fftcnt次的频谱做平均
CBLASNative.cblas_dscal(spectralLines, scale, spectrum, 1);
spectrum[0] = spectrum[0] / Sqrt2; //上一步零频上多除了根号2，这里乘回来（Rms在零频上不用除根号2，单双边到单边还是要乘2 ?）
spectralInfo.spectralLines = spectralLines;
spectralInfo.FFTSize = fftsize;
spectralInfo.windowSize = windowsize;
spectralInfo.windowType = windowType;
gch.Free();
}
public static void GetWindow(WindowType windowType, ref double[] windowdata,
out double CG, out double ENBW)
{
if (windowdata == null || windowdata.Length <= 0)
{
throw new JYDSPUserBufferException("windowdata length is null!");
}
int size = windowdata.Length;
double[] windowTmp = null;
for (int i = 0; i < size; i++)
{
windowdata[i] = i;
}
var pi2DSize = Math.PI * 2 / size;
var pi4DSize = pi2DSize * 2.0;
CG = 1;
ENBW = 0;
//根据windowType:窗函数类型产生单位窗函数
//CG:相干增益 ENBW:等效噪声宽度
switch (windowType)
{
case WindowType.Hanning: //汉宁窗
//for (i = 0; i < size; i++)//产生单位窗函数
//{
// windowdata[i] = 0.5 * (1 - cos(2 * M_PI * i / size));
//}
//汉宁窗公式:W[i]=1/2*[1-cos(2 * M_PI * i / size)] = 0.5 - 0.5 * cos(2 * M_PI * i / size);
CBLASNative.cblas_dscal(size, pi2DSize, windowdata, 1); //2 * M_PI * i / size
VMLNative.vdCos(size, windowdata, windowdata); //cos(2 * M_PI * i / size)
CBLASNative.cblas_dscal(size, -0.5, windowdata, 1); //-0.5 * cos(2 * M_PI * i / size)
for (int i = 0; i < size; i++) //0.5 - 0.5 * cos(2 * M_PI * i / size);
{
windowdata[i] += 0.5;
}
CG = 0.5; //汉宁窗的相干增益:0.5
ENBW = 1.5; //汉宁窗的等效噪声宽度;1.5
break;
case WindowType.Hamming: //海明窗
//for (int i = 0; i < size; i++)//产生单位窗函数
//{
// windowdata[i] = 0.54 - 0.46 * cos(2 * M_PI * i / size);//海明窗公式:W[i]=0.54 -0.46cos(2iπ/N);
//}
//0.54 - 0.46 * cos(2 * M_PI * i / size)
CBLASNative.cblas_dscal(size, pi2DSize, windowdata, 1); //2 * M_PI * i / size
VMLNative.vdCos(size, windowdata, windowdata); //cos(2 * M_PI * i / size)
CBLASNative.cblas_dscal(size, -0.46, windowdata, 1); //-0.46 * cos(2 * M_PI * i / size)
for (int i = 0; i < size; i++) //0.54 - 0.46 * cos(2 * M_PI * i / size);
{
windowdata[i] += 0.54;
}
CG = 0.54; //海明窗的相干增益:0.54
ENBW = 1.36283; //海明窗的等效噪声宽度:1.36283
break;
case WindowType.Blackman_Harris: // Blackman_Harris窗
//for (i = 0; i < size; i++)//产生单位窗函数
//{
// windowdata[i] = 0.42323 - 0.49755 * cos(2 * M_PI * i / size) + 0.07922 * cos(4 * M_PI * i / size);// Blackman_Harris窗公式:W[i]=0.42323-0.49755cos2iπ/N+0.07922cos4iπ/N;
//}
CBLASNative.cblas_dscal(size, pi2DSize, windowdata, 1); //2 * M_PI * i / size
VMLNative.vdCos(size, windowdata, windowdata); //cos(2 * M_PI * i / size)
CBLASNative.cblas_dscal(size, -0.49755, windowdata, 1); //-0.49755 * cos(2 * M_PI * i / size)
windowTmp = new double[size];
for (int i = 0; i < size; i++)
{
windowdata[i] += 0.42323;
windowTmp[i] = i;
}
CBLASNative.cblas_dscal(size, pi4DSize, windowTmp, 1); //4 * M_PI * i / size
VMLNative.vdCos(size, windowTmp, windowTmp); //cos(4 * M_PI * i / size)
CBLASNative.cblas_dscal(size, 0.07922, windowTmp, 1); //0.07922 * cos(4 * M_PI * i / size)
VMLNative.vdAdd(size, windowTmp, windowdata, windowdata); //0.42323 - 0.49755 * Math.Cos(2 * Math.PI * i / size) + 0.07922 * Math.Cos(4 * Math.PI * i / size);
CG = 0.42323; // Blackman_Harris窗的相干增益:0.42323
ENBW = 1.708538; // Blackman_Harris窗的等效噪声宽度:1.708538
break;
case WindowType.Exact_Blackman: //Exact Blackman窗
//for (i = 0; i < size; i++)//产生单位窗函数
//{
// windowdata[i] = 0.42659 - 0.49656 * cos(2 * M_PI * i / size) + 0.07684 * cos(4 * M_PI * i / size);//Exact Blackman窗公式:W[i]=7938/18608-(9240/18608)*cos2iπ/N+(1430/18608)*cos4iπ/N;
//}
CBLASNative.cblas_dscal(size, pi2DSize, windowdata, 1); //2 * M_PI * i / size
VMLNative.vdCos(size, windowdata, windowdata); //cos(2 * M_PI * i / size)
CBLASNative.cblas_dscal(size, -0.49656, windowdata, 1); //-0.49656 * cos(2 * M_PI * i / size)
windowTmp = new double[size];
for (int i = 0; i < size; i++) //0.42659 - 0.49656 * cos(2 * M_PI * i / size);
{
windowdata[i] += 0.42659;
windowTmp[i] = i;
}
CBLASNative.cblas_dscal(size, pi4DSize, windowTmp, 1); //4 * M_PI * i / size
VMLNative.vdCos(size, windowTmp, windowTmp); //cos(4 * M_PI * i / size)
CBLASNative.cblas_dscal(size, 0.07684, windowTmp, 1); //0.07684 * cos(4 * M_PI * i / size)
VMLNative.vdAdd(size, windowTmp, windowdata, windowdata); //0.42659 - 0.49656 * Math.Cos(2 * Math.PI * i / size) + 0.07684 * Math.Cos(4 * Math.PI * i / size);
CG = 0.42659; //Exact Blackman窗的相干增益:0.42659
ENBW = 1.69369; //Exact Blackman窗的等效噪声宽度:1.69369
break;
case WindowType.Blackman: //Blackman窗
//for (i = 0; i < size; i++)//产生单位窗函数
//{
// windowdata[i] = 0.42 - 0.5 * cos(2 * M_PI * i / size) + 0.08 * cos(4 * M_PI * i / size);//Blackman窗公式:W[i]=0.42-0.5cos2iπ/N+0.08cos4iπ/N;
//}
CBLASNative.cblas_dscal(size, pi2DSize, windowdata, 1); //2 * M_PI * i / size
VMLNative.vdCos(size, windowdata, windowdata); //cos(2 * M_PI * i / size)
CBLASNative.cblas_dscal(size, -0.5, windowdata, 1); //-0.5 * cos(2 * M_PI * i / size)
windowTmp = new double[size];
for (int i = 0; i < size; i++) //0.42 - 0.5 * cos(2 * M_PI * i / size);
{
windowdata[i] += 0.42;
windowTmp[i] = i;
}
CBLASNative.cblas_dscal(size, pi4DSize, windowTmp, 1); //4 * M_PI * i / size
VMLNative.vdCos(size, windowTmp, windowTmp); //cos(4 * M_PI * i / size)
CBLASNative.cblas_dscal(size, 0.08, windowTmp, 1); //0.08 * cos(4 * M_PI * i / size)
VMLNative.vdAdd(size, windowTmp, windowdata, windowdata); //0.42 - 0.5 * Math.Cos(2 * Math.PI * i / size) + 0.08 * Math.Cos(4 * Math.PI * i / size);
CG = 0.42; //Blackman窗的相干增益:0.42
ENBW = 1.72676; //Blackman窗的等效噪声宽度:1.72676
break;
case WindowType.Flat_Top: //平顶窗
for (int i = 0; i < size; i++) //产生单位窗函数
{
windowdata[i] = 0.21558 - 0.41663 * Math.Cos(2 * Math.PI * i / size)
+ 0.27726 * Math.Cos(4 * Math.PI * i / size)
- 0.08358 * Math.Cos(6 * Math.PI * i / size)
+ 0.00695 * Math.Cos(8 * Math.PI * i / size);
//平顶窗的公式:W(i)=0.21557895-0.41663158cos2iπ/N+0.277263158cos4iπ/N-0.083578947cos6iπ/N+0.006947368cos8iπ/N;
}
CG = 0.22; //平顶窗的相干增益:0.22
ENBW = 3.77; //平顶窗的等效噪声宽度:3.77
break;
case WindowType.Four_Term_B_Harris: //4 Term B-Harris窗
for (int i = 0; i < size; i++) //产生单位窗函数
{
windowdata[i] = 0.35875 - 0.48829 * Math.Cos(2 * Math.PI * i / size)
+ 0.14128 * Math.Cos(4 * Math.PI * i / size)
- 0.01168 * Math.Cos(6 * Math.PI * i / size);
//4 Term B-Harris窗的公式:W(i)=0.35875-0.48829cos2iπ/N+0.14128cos4iπ/N-0.01168cos6iπ/N;
}
CG = 0.35875; //4 Term B-Harris窗的相干增益:0.35875
ENBW = 2.00435; //4 Term B-Harris窗的等效噪声宽度:2.00435
break;
//7 Term B-Harris窗
case WindowType.Seven_Term_B_Harris:
for (int i = 0; i < size; i++) //产生单位窗函数
{
windowdata[i] = 0.27105 - 0.43329793923448 * Math.Cos(1 * 2 * Math.PI * i / size)
+ 0.21812299954311 * Math.Cos(2 * 2 * Math.PI * i / size)
- 0.06592544638803 * Math.Cos(3 * 2 * Math.PI * i / size)
+ 0.01081174209837 * Math.Cos(4 * 2 * Math.PI * i / size)
- 0.00077658482522 * Math.Cos(5 * 2 * Math.PI * i / size)
+ 0.00001388721735 * Math.Cos(6 * 2 * Math.PI * i / size);
}
CG = 0.27105; //7 Term B-Harris窗的相干增益:0.27105140069
ENBW = 2.63191; //7 Term B-Harris窗的等效噪声宽度:2.631905
break;
// //Low_sidelobe窗
//case Low_sidelobe://无
// //break;
//other 默认矩形窗
//矩形窗
case WindowType.None:
for (int i = 0; i < size; i++) //产生单位窗函数
{
windowdata[i] = 1.0;
}
CG = 1.0; //矩形窗的相干增益:1.0
ENBW = 1.0; //矩形窗的等效噪声宽度:1.0
break;
default:
throw new JYDSPParamException("Window type is out of range!");
}
}