查看文章

Adaptive communication is one of the hottest areas of research for last two decades or so. This technique is recommended for many 3rd Generation (3G) and 4th Generation (4G) communication standards like WIFI (IEEE 802.11 n/b/g) and WiMAX (IEEE 802.16/e) etc. These systems are mainly Orthogonal Frequency Division Multiplexing (OFDM) based communication systems. In OFDM systems there are several subcarriers that may exhibit different channel state information. In adaptive communication, the various transmission parameters like code rate, modulation scheme and power are adapted with respect to the channel state information at different subcarriers, so that the overall throughput of the system may be maximized while satisfying certain constraints like bit error rate and total transmit power, at the same time. In this paper, a comprehensive review of adaptive communication techniques along with their pros and cons and future directions is presented.