【摘要】 在无线通信系统中,当发射端未知信道的状态特性时,采用空时编码可得到分集增益与编码增益。然而,在一些无线通信系统中,发射端可能已知部分信道状态特性,因此空时编码与自适应调制相结合可更进一步提高通信系统的性能。部分信道状态信息对自适应与空时编码相结合的OFDM系统性能的影响进行了讨论。仿真比较了自适应的空时OFDM与普通的空时OFDM的性能,可为时变信道的多天线OFDM系统设计提供参考。更多还原

【Abstract】 In wireless communication, when the channel state information is unknown to the transmitter, the diversity gain and coding gain can be acquired through space-t ime coding. However, in some specific wireless communication systems, the partial channel sate information is known to the transmitter, thus the combination of space-time coding and adaptive modulation will further increase the system′s performance. In this paper, the impaction on the system performance of OFDM with the combination of space-time coding and adaptive modulation when partial channel state information is known to the transmitter is discussed. Simulation result s are provided for the comparison of the performance between the adaptive space -time OFDM system and the common space-time OFDM system, and may be used as are ference design of time varying OFDM system with transmit diversity.更多还原