Assuming you have tried to get the owners downstairs to cut down the noise by asking them to put down rugs and be more considerate, and they haven’t complied, now check your by-laws.
There should be one that says something like “An owner or occupier of a lot must not create any noise on the parcel likely to interfere with the peaceful enjoyment of the owner or occupier of another lot or of any person lawfully using common property.”
There may even be a by-law that forbids owners from removing carpet without permission or subject to the installation of sound insulation.
If either of these are in place, ask your strata committee and/or strata manager to issue a Notice To Comply. In the meantime, start recording the noise, create a noise diary of the kind of excessive noise and when it happened, and get visitors and other owners to give you statutory declarations witnessing the noise from below.
If the committee or strata manager won’t help, apply to Fair Trading for mediation with a view to seeking orders at NCAT.