On Thu, May 13, 2010 at 1:18 AM, marcin_w <mwie9...@uni.sydney.edu.au> wrote: > > > Eric Blossom wrote: >> >> Your baseband sample rate is 100M/32 -> 3.125MS/s >> >> You're using 2 samples/symbol, thus your symbol rate is >> 3.125MS/s / 2 -> 1.5625Msymbols/s >> And since you're using DBPSK, you're getting 1 bit/symbol, thus your >> raw over-the-air bit rate is 1.5625Mbit/s >> > > Hi Eric, a quick question about this. > > According to: > _pick_bitrate(bitrate, bits_per_symbol, samples_per_symbol, xrate, > converter_rate, xrates, gen_info) in pick_bitrate.py > > when the samples per symbol and interpolation are given, then our bitrate > can be determined straight away. > i.e Bitrate = converter_rate / xrate / samples_per_symbol > > Is this correct though, in determining the bitrate for both dbpsk & dqpsk? > For instance if we passed the_pick_bitrate() function an interpolation of > 128 and Samples/symbol of 2, then according to the code, our bit rate for > both dqpsk and dbpsk will be 500kbs. > > But according to what your saying: > 1) for dbpsk > > if DAC rate = 128e6 Interpolation = 128 Samples/symbol = 2 > Bitrate = 128e6 / 128 / 2 = 500k > > 2) for dqpsk > > Using the same parameters > Bitrate = 128e6 / 128 / 2 / 2bits per symbol = 256K > > Have i missed something here, or in the code? > > Regards, > > Marcin
This does appear to be a bug. That calculation in pick_bitrate.py should also be divided by bits_per_symbol. Tom _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
