Re: [Discuss-gnuradio] gr-lte updated to GNU Radio 3.7 API

[Johannes Demel]

Currently synchronization doesn't support fractional CPs. Besides this, reducing the sample rate helps a lot to make it run faster. Only thing to keep in mind though, having a different number of blocks than used by the base station will only allow you to decode PBCH. But for a start. That's not much of a problem.

On Thu, Dec 19, 2013 at 10:33 AM, Tom Tsou <address@hidden> wrote:

On Thu, Dec 19, 2013 at 12:55 PM, Johannes Demel
<address@hidden> wrote:
> Technically it could work with life data. Unfortunately it creates a too
> heavy load to be processed in realtime, unless you have the computing power
> or reduce the bandwidth/fft length to a small value. But then you are
> probably not able to decode more than the PBCH.

It's certainly possible, and advisable, to downsample from a full LTE
capturing bandwidth to a more manageable rate of 1.92 Msps or 960
ksps. The latter can be handled very efficiently for initial
acquisition, though the cyclic prefix length becomes fractional, which
is annoying to handle. In either case, the complexity of the
downsampling is mainly dictated by the output rate of the resampler.

Done efficiently, even a small processor can handle PBCH decoding from
a relatively high capture sample rate. Though, this would require a
rather substantial change from the gr-lte synchronization approach and
overall structure.

  -TT