Bits transmitted by every subchannel are determined by its value of Signal to Noise Ratio(SNR), and the unwanted power caused by noise is distributed to every subchannel, so their damage is weakened.

• 它根据各个子信道信噪比的情况确定其传送比特数，由噪声引起的干扰功率被分散到各个子信道中，降低了其引起的干扰。