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Wireless & Mobility · Foundational

Modulation

Varying a carrier wave's amplitude, frequency, or phase to encode data.

Definition

Modulation converts digital bits into changes in an RF carrier. Basic forms are amplitude, frequency, and phase keying, and QAM combines amplitude and phase. More complex modulation carries more bits per symbol but requires higher SNR.

Example

256-QAM encodes 8 bits per symbol.

Exam tip

Higher-order modulation increases data rate only when SNR is high enough.

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