PERFORMANCE COMPARISON OF EQUALIZATION TECHNIQUES FOR DSL SYSTEM

Abstract

Orthogonal Frequency Division Multiplexing (OFDM) and Discrete Multi-tone Modulation (DMT) are two types of Multicarrier Modulation (MCM) techniques. MCM is used to transmit data through multi channels. The difference between both OFDM and DMT is of bit loading. The method of loading bits to multi channels is that in DMT we calculate SNR of individual multi channel and then up to that particular response the bits are loaded, the better the response the more number of bits are loaded. While in OFDM the bits are loaded equally irrespective of the channel response. Now considering these two techniques, DSL channel is used in this project and two types of equalization techniques are used and their performance comparison is done on the basis if Bit Error Rate (BER). In telecommunications, equalizers are used to provide the frequency response for example of a telephone line from end-to-end. When channels have been "equalized" the frequency domain attributes of the signal at the input are truly reproduced at the production. Telephones, DSL lines and television cables use equalizers to organize data signals for broadcast. So, motivation for this project was to find out the most efficient equalizer in the DSL system. We compared the equalizers in such a way that we achieve maximum bit rate or bits per error.