I have the same problem. I am using different channel models for
simulation and some samples either disappear or are incorrect. In your
answer, group delay = (N-1)/2, I assume that N is the number of taps of
the filter. So, how can I compensate this delay to obtain the correct
samples at the receiver?
Thanks so much
Tom R. wrote in post #1115636:
On Wed, Jul 10, 2013 at 8:42 AM, Gregory W. [email protected] wrote:
calculating BER), it is necessary to account for the 3-sample offset.
documentation except to say that you need to calculate the total group
delay of your system if you want to align the data.
Is there a straightforward way to calculate group delay for a flow graph?
Alternatively, would it be straightforward to create a block that annotates the
data stream with a time index and another block that uses this
Symmetric FIR filters have a known group delay of (N-1)/2. So what you
need to do is a) make sure all of your filters are symmetric FIRs (and
they probably are; firdes and optfir produce these types of filters)
and b) know all of the filters in the path, which includes the
transmit and receive pulse shaping filters and any filter in the
channel model (used to simulate multipath). You should be able to add
up the group delays of all filters to get your answer.