OFDM using system generator..

hi guys! i am currently working on implementation of channel equalizer for OFDM using xilinx system generator. But i have stuck at one point please help me out of this>
Problem is is that i want to implement 16 bit qam using xilinx blocksets.And i unable to define 16 bit qam using xilinx block .if anybody had done before this then please show me how you have done it...
bye...

Hi, I am now doing my final year project regarding FPGA , ISE and MATLAB, and the time is very rush and limited for me. I am now using FPGA Xilinx Spartan 3A evaluation kit. My main objectives is to use MATLAB SIMULINK to constrcut a block diagram and using Xilinx system generator to generate HDL code. After that load the program into the evaluation kit to perform output. Due to the problem that i am new in this field and XILINX, i would like to ask anyone can give me some idea in order to solve this problem. Thank you...

Where are you facing a problem? Designing a block in simulink or implementation of hdl code in ISE?
Can you please elaborate your objective in this project? I designed various filters using Matlab FDA-tool & system generator, so I think I can help you on this.