Channel sounding and synchronization of continuous streams of data

Hello,

I am trying to implement a channel sounder using gnuradio-companion. I
have
attached the snapshots of my transmitter and receiver with the email.

In the transmitter, a GLFSR float source is going through a root raised
cosine filter and then getting connected to the real input of USRP. I am
storing the complex I&Q samples in a sink file in the receiver.
Thereafter,
I am correlating the complex samples with the reference GLFSR sequence
offline.

Expectedly, my setup is suffering from synchronization issue since I
don’t
have any synchronizer block in the receiver setup. This issue worsens
with
higher number of chips. Based on this setup, I have the following
questions:

  1. Has anyone implemented a channel sounder in grc before? In an earlier
    email (
    http://lists.gnu.org/archive/html/discuss-gnuradio/2010-05/msg00058.html),
    Jonathan said that there is a plan of re-implementing gr-sounder with
    synchronization. I am just curious if anyone took that path.

  2. How can I synchronize a continuous stream of I&Q data? If I put a
    costas
    loop and M&M recovery block between the USRP source and the file sink,
    will
    it resolve the issue?

Any suggestion will be really helpful.

Thanks,

Nazmul


Muhammad Nazmul I.hi

Graduate Student
Electrical & Computer Engineering
Wireless Information & Networking Laboratory
Rutgers, USA.