I have an idea. It involves creativity mixed with a little work. That usually does the trick for this sort of problem.
Did you even look at the above link? If you didn't, do so. If you did, look again.
The file exchange there always turns up plenty of inspiration. And yes, that requires work because no, chances of someone providing exactly what you want are small. Then again, said chances are hard to compute given the current vagueness of your specifications.
Because I can randomly make up a matlab script on the spot that 100% fulfills the "randomly generated data into packets and then interleave them" requirement and almost certainly is 0% of what you want. So either do work and search for matlab tidbits you can use, or happily hope that someone will provide stuff for you. If you intend to do the latter I suggest you become a LOT MORE SPECIFIC and exact and all that good engineering shit when it comes to specifications. What packets? tcp packets? udp packets? DHL packets? wut?
Interleaving? bit interleaving? byte interleaving? hypergalactic hamster interleaving?