QAM modulation technique using verilog

Thanks for your comments, however:

With regard to -1, +1 you are possibly using a tool like DSP builder which eventually converts values.

For final mapping you need to use full resolution for all levels of I/Q.

quadrature modulation through upconversion(shift of baseband) to a carrier can be left to analogue people.

shaping filter is most likely needed though some primitive comms can do without shaping. upsampling to DAC speed is important.

If you decide for frequency shift then you need to multiply with full signal resolution otherwise your information will be lost in air or cables and will be just sending sine waves.