[Discuss-gnuradio] Channel sounding and synchronization of continuous streams of data

[Nazmul Islam]

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 Islamhi

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

sounder_transmitter.grc
Description: application/gnuradio-grc

sounder_receiver.grc
Description: application/gnuradio-grc

sounder_transmitter.png
Description: PNG image

sounder_receiver.png
Description: PNG image