# Eye Diagram of QPSK Modulated Signal

I need to plot eye diagram for RRC filtered QPSK modulated signal. The specifications are given as follows

Sampling frequency : $1.024$ MHz

Symbol Rate : $256$ Kbps (Hence, Upsampling rate = $4$)

Roll off factor = $0.2$

So I wrote a matlab code, but the resolution of eye diagram plotted is very low. I used object commscope.eyediagram.

Increasing the sampling frequency gives a better resolution, but it also increases the number of taps in the RRC filter which would not be a viable option for hardware implementation.

Kindly suggest what changes I need to make to get a better resolution of eye diagram without increasing the sampling frequency?