Packet sending interval

GNU Radio
1

Hi,

I am using the OFDM benchmark code in USRP2, where my system is Ubuntu
9.10

  • Gnuradio 3.2.2.
    Basically I used the following scripting for TX and RX:
    $ sudo python benchmark_ofdm_tx_new.py --mac-addr=00:50:c2:85:32:97 -f
    2.462G -m qpsk -i 100 --tx-gain=30 -M 8 -s 1000 --fft-length=512
    –occupied-tones=200 --cp-length=128
    $ sudo python benchmark_ofdm_rx_new.py --mac-addr=00:50:c2:85:32:99 -f
    2.462G -m qpsk -d 100 --rx-gain=30 --fft-length=512 --occupied-tones=200
    –cp-length=128

As observed from spectrum analyzer, I found out the OFDM symbols are NOT
stably transmitting. Furthermore, the packet sending interval is large (
in
low rate)
Then, how can I control the sending rate/interval of OFDM packets?

The related code for “send_pkt” is as follows:

def send_pkt(self, payload=’’, eof=False):
“”"
Send the payload.

    @param payload: data to send
    @type payload: string
    """
    if eof:
        msg = gr.message(1)              # tell self._pkt_input

we’re
not sending any more packets
else:
info = ofdm_packet_utils.get_info(payload, self._regime,
self._symbol_time)
N_cbps = info[“N_cbps”]
N_bpsc = info[“N_bpsc”]
N_rate = info[“rate”]
N_sym = info[“N_sym”]

    (pkt,Length) = ofdm_packet_utils.ftw_make(payload,self._regime,

self._symbol_time)
(pkt_scrambled,Length) = ofdm_packet_utils.scrambler(pkt,Length)

    pkt_coded = ofdm_packet_utils.conv_encoder(pkt_scrambled,

Length,
self._regime, N_cbps, N_bpsc, N_sym, N_rate)
pkt_interleaved = ofdm_packet_utils.interleaver(pkt_coded ,
self._regime, N_cbps, N_bpsc)
msg = gr.message_from_string(pkt_interleaved)

    self._pkt_input.msgq().insert_tail(msg)