Eric B. <eb comsec.com> writes:
On Mon, Jan 05, 2009 at 06:52:56PM +0200, Sebastiaan H. wrote:
Unlike what the code would lead you to believe, you have to provide
the filter taps. See gr-pager/src/usrp_flex_band.py for a working example.
I found some API Docu about the analysis filterbank, but still
have some questions to it.
First i post a clipping from the api docu about the analysis filterbank:
00043 def init(self, mpoints, taps=None):
00045 Takes M complex streams in, produces single complex stream
00046 that runs at M times the input sample rate
00048 @param mpoints: number of freq bins/interpolation
00049 @param taps: filter taps for subband filter
00051 The channel spacing is equal to the input sample rate.
00052 The total bandwidth and output sample rate are equal the
00053 sample rate * nchannels.
00055 Output stream to frequency mapping:
00057 channel zero is at zero frequency.
00059 if mpoints is odd:
00061 Channels with increasing positive frequencies come
00062 channels 1 through (N-1)/2.
00064 Channel (N+1)/2 is the maximum negative frequency, and
00065 frequency increases through N-1 which is one channel
00066 than the zero frequency.
What do you mean in line 61 + 62 ?
If i have 3 Mpoints, then my first channel comes from 1 to 0 ?
channel 2 comes from 1 to 0.5 ?
Channel 3 comes from 1 to 1 ?
If i have 3 mpoints than i have 3 channels, right ?
can somebody give a more detailed explanation ?