Evolution of Orthogonal Frequency Division Multiplexing Modulation to Discrete Wavelet Multitone

Abstract

Orthogonal frequency division multiplexing (OFDM) was proposed in literature as a measure to counter inter-symbol interference (ISI). OFDM has been standardized in various IEEE standards, such as wireless LANS, digital audio broadcasting etc. However, OFDM has a few disadvantages, concerned with the addition of redundant data in cyclic-prefix that it carries. Moreover, its high side-lobes result in significant signal interference. Therefore, a variant of OFDM, namely Discrete Wavelet Multi-tone (DWMT) in wire line and Wavelet OFDM (WOFDM) in wireless channel was proposed in recent history. We have outlined the motivation behind this evolution from OFDM to WOFDM, and have given an overview of its performance analysis as discussed in literature.