自适应调制和编码（Adaptive modulation and coding；AMC）是根据终端（UE）和Node-B提供的消息，改变调制和编码的格式，使其适应在系统限制范围内和信道条件。

HSDPA实现AMC的方法：

• 选择调制型态（modulation type），利用位相偏移变调（QPSK）正交振幅调制（16QAM）来清除信道。
• 选择前向纠错编码（FEC）

Link adaptation, or adaptive modulation and coding (AMC), is a term used in wireless communications to denote the matching of the modulation, coding and other signal and protocol parameters to the conditions on the radio link (e.g. the pathloss, the interference due to signals coming from other transmitters, the sensitivity of the receiver, the available transmitter power margin, etc.). For example, WiMAX uses a rate adaptation algorithm that adapts the modulation and coding scheme (MCS) according to the quality of the radio channel, and thus the bit rate and robustness of data transmission. The process of link adaptation is a dynamic one and the signal and protocol parameters change as the radio link conditions change—for example in High-Speed Downlink Packet Access (HSDPA) in Universal Mobile Telecommunications System (UMTS) this can take place every 2 ms.