关键词: 自适应调制编码, 衰落信道, 时变信道

Abstract:

Because of the characteristics of wireless time-varying fading channels,there are a lot of uncertainties in the process of communication in the mobile communication system.The adaptive approach can improve the transmission rate or decrease the transmit power when the channel condition is good and decease the rate or increase the power.Simulation results show that the adaptive modulation of system based on the channel conditions can improve the transmission rate at a low BER,and thus better transmission reliability and utilization of bandwidth result.

Key words: adaptive modulation and coding;time varying fading channels;fading channels