The channel model2 has the potential to lock up the flowgraph if the delay and frequency are provided from the same (two-output) sync_block. The lockup happens after millions of samples for reasonable values of offset rate. The frequency input is consumed by the 'VCO' block at a the output rate of the resampler. However, the timing input is consumed at the input rate of the resampler. Given a sufficiently long simulation the frequency buffer can become full while the resampler buffer is empty (or vv). This will take ~ 16k / rate_offset. I would suggest changing the order of the VCO and resampler.
Note that there is a slight difference in the output that would have to be accounted for when computing the frequency (negligible for 99.99% of applications). ________________________ Eugene Grayver, Ph.D. Aerospace Corp., Principal Engineer Tel: 310.336.1274 ________________________
