I/Q Modulation Questions

Discussion in 'Wireless & RF Design' started by mossman, Apr 1, 2011.

  1. mossman

    Thread Starter Member

    Aug 26, 2010
    I'm studying up on I/Q modulation (4-QAM in particular) and am having difficulty finding references pertaining to the baseband I and Q signals. I understand that the I and Q signals are mixed with a 0 degree carrier and a 90 degree carrier, but what happens to the digital baseband signal prior to this stage? In other words, if I have a 4-QAM system, how are the 0's and 1's converted? Is a DSP used to group the data bits in two's (for QAM) then output an analog voltage on the I and Q data lines, which then modulate the carriers?
  2. bertus


    Apr 5, 2008