OFDM receiver error, FATAL: Missing a required length tag on port 0 at item #0

GNU Radio
1

Hi,

I implemented OFDM receiver on USRP E110 using the OFDM receiver in
examples in gnuradio’s files 3.7

and I added to it a chain to create OFDM transmitter: random source,
OFDM
transmitter, channel model, throttle, USRP sink

But when I executed the flow graph. It generated “UOOOOOOOOOOOOOOOOOO”
and
I got an error :

FATAL: Missing a required length tag on port 0 at item #0
thread[thread-per-block[21]: <gr_block crc 32_bb (9)>]: Missing length
tag.

and tag debug didn’t show anything.

Have you an idea how to fix this error ?

Thanks in advance

2

On 06/30/2014 09:20 AM, Wafa E. wrote:

Hi,

I implemented OFDM receiver on USRP E110 using the OFDM receiver in
examples in gnuradio’s files 3.7

and I added to it a chain to create OFDM transmitter: random source, OFDM
transmitter, channel model, throttle, USRP sink

But when I executed the flow graph. It generated “UOOOOOOOOOOOOOOOOOO” and
I got an error :

Slow the data rate until this message stops. Then worry about the next
message.

Philip

3

Hi, thank you for your response.

In fact, I still have the same error:
FATAL: Missing a required length tag on port 0 at item #0
thread[thread-per-block[21]: <gr_block crc 32_bb (9)>]: Missing length
tag.
and UOOOOOOOOOOOOOO
I put the usrp sink and usrp source 's sample rate to 1M.

What is the suitable sampling rate to put ?

Thanks in advance

2014-06-30 16:36 GMT+02:00 Philip B. [email protected]:

4

On 06/30/2014 03:20 PM, Wafa E. wrote:

FATAL: Missing a required length tag on port 0 at item #0
thread[thread-per-block[21]: <gr_block crc 32_bb (9)>]: Missing length tag.

Add a stream to tagged stream converter.

M