Hi,

regarding the different parameters. 'tx_diversity' should always be left as
it is. In case of a 1x1 MIMO configuration it will just have no effect.
This parameter reflects the LTE standard with its two options
'tx_diversity' and 'spatial_multiplexing'. The latter isn't used for
control channels.
In order to specify a certain bandwidth, use the parameter 'N_rb_dl', which
specifies the number of resource blocks used. This will also set the
bandwidth as this is the unit given by the system to determine the
bandwidth. e.g. have a look at the paper which is included in the project
there is a table which shows the dependencies.
25 RBs --> 25*12 = 300 subcarrier --> 15kHz * 300 + spacing = 5MHz.
The FFT length can be chosen freely as long as it provides sufficient bins
to match the current number of subcarriers. It will be used to determine
the input sample rate. I suggest you stick with power of 2 values. Those
are the only ones I tested and the numbers the system is designed for. One
more thing, a FFT length shorter than 256 results in fractional CP lengths,
which should be avoided. LTE's CP use is already quite tricky and the
introduction of fractional CP lengths will not ease the situation.
PBCH decoding is handled for one and two antenna configurations, so you
don't have to worry about configuring the flowgraph there.
PCFICH decoding will receive a message on runtime which sets the decoded
antenna configuration.

Happy hacking
Johannes


On Fri, Dec 20, 2013 at 2:39 AM, Baier <ba...@irt.de> wrote:

> Hi Johannes,
>
> thank you very much for updating your gr-lte package. I could compiled all
> .grc files succesfully. Now I would like to test your receiver with a LTE
> signal saved to a file with the following settings.( 5 MHz, RB 25, fft 512,
> occupied carriers 300, no tx diversity). So I have started to change the
> parameters in your grc files.
> RB 25 instead 50
> fftlen 512 instead 2048(is it right?)
> occupied carriers 300 instead 600.
> So I have realized the files decode_pcfich_37.grc and decode_pbch_37 .grc
> are designed for tx_diversity with two antennas. How can I change it?
> Removing the blocks for the second antenna perhaps?
> Thank you very much.
> A. Baier
>
>
>
>
>
>
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