Karan, the current 'master' branch has a "multiply_matrix_cc" block which might be what you're looking for.
M On 08/06/2014 08:47 AM, Karan Talasila wrote: > Hi, > we are trying to implement alamouti encoding and decoding on an > underlying ofdm communication system in Gnuradio. So we are using > benchmark_tx.py. In ofdm mapper block we have written our own block > which does alamouti encoding which gives out alamouti encoded symbols > across two output ports. The first output port will give x1 and -x2*. > The second output port will give x2 and x1* according to the alamouti code. > > Now, from each of these two output ports, we are connecting an insert > preamble block followed by an IFFT block and then a cyclic prefixer > block. All of these blocks are standard gnuradio blocks used in ofdm > examples directory in gnuradio( benchmark_tx.py). Now we would want to > connect these two ouputs to their respective usrp sink blocks thereby > implementing a mimo system with 2 transmitters. > > Now we are using an alamouti decoder block which is implemented in ofdm > frame acquisition block. Before we put it on usrp's which require > perfect hardware time synchronisation, we would like to test whether > our end to end transmitter and receiver in software is working. So we > connected the txpath1 to rxpath1 and txpath2 to rxpath2 which is like > connecting two transmitters to two receivers directly. But we are not > receiving the decoded symbols properly. when we are debugging, we are > having doubts as to maybe the H matrix(channel matrix) values of h12 and > h21 might not be received because we are connecting transmitter 1 to > receiver 1 and transmitter 2 to receiver 2. can that be an issue? > > In general how do you test mimo blocks in software. Is the way we are > doing right i.e. connecting txpath1 to rxpath1 and txpath2 to rxpath2. > Or are there other better ways of testing end to end MIMO systems > without hardware? > > > > -- > Regards > Karan Talasila > > > _______________________________________________ > Discuss-gnuradio mailing list > [email protected] > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio > _______________________________________________ Discuss-gnuradio mailing list [email protected] https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
