Hi Josh, I have done the same work as Alex. I modified the code in gr_message_source. I added a tx_sob tag and a tx_time tag to the first byte of the message, and a tx_eob tag to the last byte of the message. Assuming: 1. there are 100 bytes in a message(or we call it a packet) 2. bpsk modulation is employed 3. set samples_per_symbol to 2 So there are 800 symbols or 1600 samples in the packet. In the output of the gr_message_source block, the 0 byte is tagged with the tx_sob and the tx_time, and the 99 byte is tagged with the tx_eob.
Then in the output of the symbol map block, the 0 symbol is tagged with the tx_sob and the tx_time, and the 792 symbol is tagged with the tx_eob. After pulse shaping filter, the 0 sample is tagged with the tx_sob and the tx_time, and the 1584 sample is tagged with the tx_eob. My questions are as follow: 1. The 1599 sample is the last sample in the packet, but the tx_eob tag are added to the 1584 sample. So, what will happen to the 1585-1599 samples in the usrp? Are they transmitted by the usrp immediately after the 1584 sample? 2. Is it necessary to adding the tx_eob tag exactly to the last (1599) sample? How can I do this? Best regards, King Qiu _______________________________________________ Discuss-gnuradio mailing list [email protected] https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
