FW: Help Req:MIMO OFDM

GNU Radio
1

Hi,
I wanted to ask you that if i want to send two independent data streams
to
two daughter boards mounted on one usrp, wats the command for it.
If i want to explicitly send data1 to sub(0,0) and data 2 to subdev(0,1)
SIMULTANEOUSLY…then how do you do it?
I have read few examples but im not able to solve the issue. Here is the
ref code posted by Mr.Sungro
Yoon________________________________________________________________________________________________________________
self._pkt_input1 = gr.message_source(gr.sizeof_char, msgq_limit)
self._pkt_input2 = gr.message_source(gr.sizeof_char, msgq_limit)

intl = gr.interleave(gr.sizeof_char)

self.connect(self._pkt_input1, (intl, 0))
self.connect(self._pkt_input2, (intl, 1))

self.connect(intl, self)

self._u = usrp.sink_c (which=self._which,
nchan=2,
fusb_block_size=self._fusb_block_size,
fusb_nblocks=self._fusb_nblocks)

self._subdev = (self._u.db(0, 0), self._u.db(1, 0))
self._u.set_mux(0xba98)

self._subdev[0].set_gain(self._subdev[0].gain_range()[1]) #
set max Tx gain
self._subdev[1].set_gain(self._subdev[1].gain_range()[1]) #
set max Tx gain

self.set_freq(0, freq0)
self.set_freq(1, freq1)

self._subdev[0].set_enable(True) # enable
transmitter
self._subdev[1].set_enable(True) # enable
transmitter

self._dxc = self._which

self.connect(self, self._u)

here you are simultaneously transmitting , but its one stream that both
the
subdev are simultaneously transmitting.

In my case i have two independent streams.

Thanks in advance.

Regards,

Nadia

2

On Fri, Jan 08, 2010 at 07:24:14PM +0000, nadia raj wrote:

Hi,
I wanted to ask you that if i want to send two independent data streams to
two daughter boards mounted on one usrp, wats the command for it.
If i want to explicitly send data1 to sub(0,0) and data 2 to subdev(0,1)
SIMULTANEOUSLY…then how do you do it?
I have read few examples but im not able to solve the issue. Here is the ref code posted by Mr.Sungro Yoon________________________________________________________________________________________________________________

Given that I think you keep asking the same question, and that I keep
pointing you to fm_tx_2_daughterboards.py and you say you understand
how it works, either you don’t understand what’s going on in
fm_tx_2_daughterboards.py, or I’m failing to understand your question.

Have you actually used a spectrum analyzer or o’scope to examine the
outputs of the two daughterboards when running
fm_tx_2_daughterboards.py?

I promise you that they are in fact outputting two independent streams.
The two streams are both continuous, and if the problem is that you
want the two streams to be independently discontinuous, then you can’t
do that with a single USRP and 2 daughterboards, using the FPGA images
we distribute. I don’t think that’s what you’re trying to do, given
that I think you want to do MIMO.

Eric