【摘要】 离散多音频(Discrete Multitone,DMT)调制是指高效利用信道,通过对不同的子信道发送不同长度的比特来得到最大信息流量的多载波调制(Multi-Carrier Modulation,MCM)的一种特殊形式。每个子信道上的比特取决于该子信道的信噪比。通过采用先进的编码技术可以进一步提高DMT系统的性能。笔者对DMT系统中的编码技术和调制方式进行了研究。编码采用的是与Berlek-apmp Massey(BM)算法相结合的里德索罗蒙码(Reed Solomon,RS);调制采用离散傅立叶变换(DiscreteFourier Transform,DFT),并对里德索罗蒙码和离散傅立叶变换的基本原理进行了概述。随后讨论了该编码实施方案的潜在效益。仿真结果显示当误码率为10-7时,其编码增益相对于未编码增加了3至6 dB。更多还原

【Abstract】 Discrete Multitone（DMT） modulation is a particular form of multicarrier modulation which makes efficient use of the channel,maximizing the throughput by sending different numbers of bits on different subchannels.The number of bits on each subchannel depends on the Signal-to-Noise Ratio of the subchannel.The performance of a DMT system can be further increased by using powerful coding techniques.In this paper,we investigate an implementation of coding for a DMT system.The coding techniques considered are Reed Solomon（RS） coding combined with Berlekapmp Massey algorithm,and Discrete Fourier Transform（DFT）.The fundamentals of RS code and DFT are outlined.We discuss the implementation issues and potential benefits of the coded DMT.Simulation shows that at a bit error probability of 10^-7 the suggested codes gain 3⁶ dB over uncoded transmission.更多还原