Not really about the OTL late 1943, but in this ATL, somehow IJN managed not to lose any more carriers after Coral Sea, they extended their perimeter a bit more, in the New Hebrides and several other small islands. There have been a sort of stalemate since late 1942, punctured by intense air action in the Southwest Pacific and especially New Guinea. They have lost Midway in 1942 and the Aleutian outposts in spring/summer 1943 (they were too late to catch the invasion fleet). They have carried some damaging commerce raiding operations in the Indian Ocean.
They have taken heavy losses in the air (as OTL they still gave as good as they got) but the carrier groups are still in good shape. Now they are waiting for the inevitable US push.
Conversely the US somehow managed to lose all the pre-war carriers except Saratoga. They couldn't advance toward the New Hebrides and the Solomons or other islands because they didn't had the carriers to support landings and protect against IJN. After those losses they ordered even more Essexes and CVL conversions. But by second half of 1943 they received or receiving 10 new carriers, Essex and Independence class, with more to come. Not to mention scores of CVEs.
So, where is this carrier battle taking place, in the South Pacific or the Central Pacific? Are the US forces trying to advance in the Solomons to isolate Rabaul, or do they go straight for the Central Pacific?