Hi I have a now 7 year old ds. He is on the spectrum and has always thrown humdinger tantrums. (though life has gone slowly and steadily better and easier as he has got older)
I think that frustration is a huge part of it. Your ds has the language barriers and if he is on the spectrum he also has the confusion about how the social world works barriers as well.
Part of the tantrum throwing is completely normal and to be expected with a 3 year old. The part that doesn't always work is the how you deal with it part. My son does not get on with conventional methods of dealing with tantrums at all. It has taken trial and error to discover tactics that work with my ds and as he matures his needs and abilities change and therefore so do the tactics that work with him making it a continual journey which I think every parent is on.
Things that helped at 3 were....very, very predictable timetable. We got up the same time and did things in the same order or we had lots and lots of warnings and discussions if something new was on the horizon. We didn't have communication issues but you could try signing/ taking photos of common things he wants/ does that he could point to to help him lessen his frustration for trying to tell you things. Every night religiously we would tell him three things/events/times of the day that really shone for us (there were many, many days that this was really, really hard as he could have some hellish days...but it could be something as far reaching as...I liked that you calmed down quicker than you usually do (even if it is 3 hours 50 minutes instead of 4 hours),. Doing this really helped us to keep a note that there were positives, it helped him to see what we wanted more of and it helped to end every day no matter how hellish nicely.
In the actual midst of temper tantrums we tried several things including physically holding our ds which he hated. At 3 however he lost complete and utter control and was actually unable to bring himself back which was quite frightening for him and in turn made the tantrum much worse if you follow what I am trying to say. In the end the best thing for ds was for him to be put in a safe place where he couldn't hurt himself/ me or anything and for me to be where he could hear me and I would just broken record him "Im here, calm down, you are ok, Im here, calm down, you are ok....ad naseum. It has taken a long time but ds still needs this message and can now come out of a meltdown in less than 20 minutes which if you had met him at 3 is quite a statement.
Sorry for the essay, I hope some of it helps.