연세대학껓 기초디지털실험 10주차 결과레포트 (Filter/Equalizer)

Ⅰ. Experiment
1. filter/equalizer in C
The IP block of the previous project was exported to hardware and launched to vitis. First, I changed the coefficient of filter to match the sampling frequency used in our project. I used the first order LPF, the first order HPF, and the second order BPF. LPF follows the following formula, and the sampling frequency in our project is   . The calculation process for each coefficient is as follows.

HPF transfer function follows the following expressions, and the calculation of coefficients for HPF is as follows:

<중 략>

First, I implemented functions of lpf, hpf and bpf and equalizer functions. lpf and bpf have the same difference equation. Each filter receives 3000*256 arrays of the Frequency domain, filters them, and returns filtered arrays of the same size to output. First of all, LPF declares a coefficient, and since the sign of  is reversed by moving oppositely, the declaration is made with – in front of it. Then apply the difference estimate according to the column and row of the array. First, when j=0, divide the case by using the if-else statement as the first input (i=0) and the rest. In the first input, the first input is placed in the output[0][0] because the previous output or previous input does not exist. After that, both y[n-1] and x[n-1] are present, so they follow the general difference equation.