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Chapter 16
In-Phase and Quadrature (IQ) Signals
This chapter will explore amplitude modulation in а little moredetail. The objectives
аге
1. То take а brief look at broadcast amplitude-modulated (АМ) signals
2. То examine doubIe-sidеЬапd suppressed carrieг (DSBSC) АМ signals
З. То use the DSBSC signal to geneгate 1 and Q signals
4. То deteгmine how 1 апd Q sigпаls аге demodulated
5. То apply 1 and Q signals to softwaгe-defined radios (SDRs)
Broadcast АМ signals аге gепегаllу modulated with а carrier signal апd ап audio
signal. Theгe is only опе phase of carrier signal, and i:n the standard envelope
detection of the АМ radio signal, this phase infoгmation is normally not used. The
standard АМ signal is known as ап amplitude-modulated signal with caгrier. This
signal is illustrated ,п Figure 16-1 and characterized Ьу Equation (16-1).
