I have a doubt/question - are you really able to achieve 115.2 K baud rate with 89c52?
Can you tell how you are able to achieve this ??

Why only 115.2k you can achieve even higher baud rates using 89C52? He said he is using 22.1184MHz crystal and is using AT89C52 this chip is a 12 cycle derivative thus effective machine cycle frequency is 22118400/12=1843200 and hence the maximum baud rate achievable by setting SMOD bit in PCON register the baud rate achieved is (1843200/32)*2=115200. If you use a faster crystal or less cycle core you can achieve even more higher baud rates but then those baud rates wont' be suitable for most of the PC's you can make your microcontroller communicate with some other micro or say some other system at those baud rates.

Reagrds,
Prahlad