OFDM(正交频分复用)技术实际上是MCM(Multi-Carrier Modulation，多载波调制)的一种。其主要思想是，将信道分成若干正交子信道，将高速数据信号转换成并行的低速子数据流，调制到在每个子信道上进行传输。正交信号可以通过在接收端采用相关技术来分开，这样可以减少子信道之间的相互干扰(ICI)。每个子信道上的信号带宽小于信道的相关带宽，因此每个子信道上的可以看成平坦性衰落，从而可以消除符号间干扰。而且由于每个子信道的带宽仅仅是原信道带宽的一小部分，信道均衡变得相对容-OFDM (Orthogonal Frequency Division Multiplexing) technology is MCM (Multi-Carrier Modulation, multi-carrier modulation) is. The main idea is to channel into a number of orthogonal sub-channel, high-speed data signals into sub-parallel low-speed data streams, modulation in the transmission on each channel. Orthogonal signal at the receiving end through the use of related technologies to separate, thus reducing the mutual interference between the channel (ICI). Each channel on the signal bandwidth is less than the relevant channel bandwidth on each channel of the decline can be seen as flat, make it possible to eliminate inter-symbol interference. And because of the bandwidth of each channel is the original channel only a small portion of bandwidth, channel capacity become relatively balanced