Dear everyone:
In ofdm_receiver.py there is chan_coeffs = gr.fihan_coeffs(1.0,1.0,tb+bw,tb,gr.firdes.WIN_HAMMING), which is to determine the parameters of fir low-pass filters. My question is about the third parameter, which denotes the center of transition band, and it is computed as tb= bw*0.08. So can you explain to me why we should set the center of transition band tb+bw and how tb is computed? Besides in benchmark_rx case, midpoint of trans. band is directly set 1 and width of trans. band 0.5. So in general how do we set the bandwith and midpoint of band?
Best regards