[Discuss-gnuradio] benchmark_tx and rx : too many FALSE packet

[SangHyuk Kim]

Hi all.

I'm using benchmark_tx(rx).py example

I experimented variety modulation schemes and GMSK, BPSK, QPSK modulation worked well

However, when I used QAM modulation, most of received packet were corrupted (FALSE)

ENV)

both TX and RX uses USRP N210 with ANT500 and CBX 40MHz

distance between TX and RX is shorter than 3m

TX)

./benchmark_tx.py -f 1.5G -m qam -S 8 --tx-gain=30

RX)

./benchmark_rx.py -f 1.5G -m qam -S 8

RESULTS ON RX)

ok = FALSE  pktno = 1  n_rcvd = 1  n_right = 0
ok = FALSE  pktno = 2  n_rcvd = 2  n_right = 0
ok = FALSE  pktno = 3  n_rcvd = 3  n_right = 0
...

ok = TRUE  pktno = N  n_rcvd = N  n_right = 1
...

Is this normal case of qam modulation ?

How can I get more TRUE packet using QAM modulation ?

Thanks.