Hi all, My task was to develop a GFSK transmitter based on the following requirements • Preamble : 55 55 • Synchro : F6 72 • L-field ( data + CRC) : 20 • Data (30 bytes) : FFFFFFFFFFFFFFFFFFFFFFFFFF0110AABBBBBBCE9800010 • CRC : FECB • Modulation : GFSK • Deviation : +/-2,4KHz +0,2% • Modulation index : 2 • Filter index : 0.5 BT • Bitrate : 2400 bit/s • Carrier Frequency : 169.41 Mhz I ve designed a transmitter based on gnuradio as follow The main blocs are : 1.File source block which contain the data to be transmitted, 2. GFSK Mod block :I choose the number of samples per symbol (sps)= 100, I used the following equation to calculate the sensitivity sensitivity = Pi * modulation Index / sample par symbol and filter index BT= 0.5 3.Rotational resampler block: the interpolation = samp_rate * (sps -1) and decimation is equal to my sample_rate 4.And finally a multiply const block that feeds the USRP sink and Gui FFT and time sinks I am using gnuradio 22.214.171.124, USRP X310 with UBX daughterboard and UHD 003.010 I ve visualized my signal with a spectrum analyzer and It looks good ( I hope that what I did was correct). I would like to transmit the data above in a bursted mode, I ve tried to use the PDU to stream bloc and the unpacked to packed bloc but I was always getting a continuous transmission. Any hint please on how to make data contained in my file bursted ? Thanks in advance.
on 2017-01-04 11:06