Reconstructing original data from GMSK loopback?

GNU Radio
1

Hey all,

Is the proper way to reconstruct the original data back from modulating
and demodulating with GMSK (in loopback fashion) by packing the
outputted bits using gr.unpacked_to_packed_bb()? Since there is 1 bit
per byte (LSB), I’m assuming it needs packing. Whenever I add the
following block in the flowgraph:
gr.unpacked_to_packed_bb(self.bits_per_symbol(),gr.GR_MSB_FIRST)

… where bits_per_symbol() returns 1, I don’t quite get back the
original data before modulation. Some of the bytes are correct, but
most seem like garbage. What’s my misunderstanding?

Thanks!
George

2

On Sat, Nov 03, 2007 at 01:28:09AM -0400, George N. wrote:

original data before modulation. Some of the bytes are correct, but
most seem like garbage. What’s my misunderstanding?

Thanks!
George

George, I suggest that you start by understanding the existing
benchmark_tx/benchmark_rx and/or benchmark_loopback code.
They handle all of these details. These scripts can be found in
gnuradio-examples/python/digital.

Eric