| Communications Toolbox | |
If you use baseband modulation to produce the complex envelope y of the modulation of a message signal x, then y is a complex-valued signal that is related to the output of a passband modulator. If the modulated signal has the waveform
where fc is the carrier frequency and θ is the carrier signal's initial phase, then a baseband simulation recognizes that this equals the real part of
and models only the part inside the square brackets. Here j is the square root of -1. The complex vector y is a sampling of the complex signal
If you prefer to work with passband signals instead of baseband signals, then you can build functions that convert between the two. Be aware that passband modulation tends to be more computationally intensive than baseband modulation because the carrier signal typically needs to be sampled at a high rate.
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