Matlab DSPIC上IIR滤波器的实现

我正在使用dsplib库dsPIC30F DSP库在dsPIC上实现数字滤波器

我用MATLAB设计了我的滤波器

clc; clear all;
filter=designfilt('lowpassiir', 'FilterOrder', 4, 'PassbandFrequency', 3900, 'PassbandRipple', 1, 'SampleRate', 16000);
hd = dfilt.df2tsos(filter.Coefficients);

coef = fi(hd.sosMatrix)

fvtool(coef)

coef = 

    0.3949    0.7897    0.3949    1.0000   -0.0807    0.7538
    0.1279    0.2559    0.1279    1.0000   -0.7783    0.3203

从matlab dofumentation：

 SOS = [ b01 b11 b21  1 a11 a21
         b02 b12 b22  1 a12 a22
         ...
         b0L b1L b2L  1 a1L a2L ]

根据数据表：在有序集合{b0[s]，b1[s]，a1[s]，b2[s]，a2[s]}，0中有5个系数/秒阶（双二次）部分≤ s 我已经按照建议实施了我的系数，见下文

const float filter[10] = {0.3948975, 0.7897339, -0.0807495, 
0.3948975, 0.7538452, 0.1279297, 0.2558594, -0.77825928, 0.1279297,  
0.3203125};

const float filter_float[10] = {0.3948975, 0.7897339, -0.0807495, 
0.3948975, 0.7538452, 0.1279297, 0.2558594, -0.77825928, 0.1279297,  
0.3203125};

fractional filter[10]; // 5

for(i=0; i<10; i++){
    filter[i]=Float2Fract(filter_float[i]);
}

fractional dbIr_1[2], dbIr_2[2];    // Delay-Line-Buffer I-Filte
(Segment 1 and 2)  
IIRTransposedStruct Filter; 
Filter.coeffsBase=filter;       // Sets the filtercoefficients
Filter.numSectionsLess1=1;      // Define number of sections
Filter.finalShift=0;            // Define shift of output (-1 
Filter.delayBase1=dbIr_1;       // Sets the delayline buffer
Filter.delayBase2=dbIr_2;       // --
Filter.coeffsPage=COEFFS_IN_DATA;   // Coefficient are stored in data 
IIRTransposedInit(&Filter);     // Initialize the filter

int blockLength=16;
int iyr[blockLength] = {0};

main{
    IIRTransposed (blockLength, iyl, xl, &Filter);
}

const float filter[10]={0.3948975,0.7897339，-0.0807495，
0.3948975, 0.7538452, 0.1279297, 0.2558594, -0.77825928, 0.1279297,  
0.3203125};
常量浮点过滤器_float[10]={0.3948975，0.7897339，-0.0807495，
0.3948975, 0.7538452, 0.1279297, 0.2558594, -0.77825928, 0.1279297,  
0.3203125};
分数滤波器[10]；//5.
对于（i=0；iI）已使用此过滤器系数const float filteru float[10]={0.178447，-0.422417,0.844834,0.250000，-0.356893,0.178970，-0.495371,0.495371,0.500000，-0.178970}对同一代码进行了尝试我这里有声音。信号采样频率为16kHz。我今天尝试了更多，似乎存在稳定性问题。我尝试了不同的滤波器配置，要么声音在1秒后消失，要么是非常机械的，比如溢出之类的。