System complexity

System complexity refers to the amount of circuits involved and the technical difficulty of the system. Associated with the system complexity is the cost of manufacturing, which is of course a major concern in choosing a modulation technique.

Usually the demodulator is more complex than the modulator. Coherent demodulator is much more complex than noncoherent demodulator since carrier recovery is

required. For some demodulation methods, sophisticated algorithms like the Viterbi

algorithm are required. All of these are the basis for complexity comparison.