The first radio broadcasts were made using amplitudemodulation.
最初的无线电广播设备采用的是波幅调制。
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From this point, M-ary Quadrature Amplitudemodulation (MQAM), MultiCarrier modulation (MCM) and adaptive modulation techniques are good candidates in next generation mobile radio system.
The ultra wideband (UWB) radio models have been introduced with pulse-position-modulation (PPM), on-off-keying (OOK) and pulse-amplitude-modulation (PAM).