Compensation of narrowband interference in generalized discrete multitone modulation

The generalized DMT (GDMT) provides a low latency high data rate transmission over copper cables constituting a solution for many symmetrical data services up to 2 Mbps. The low latency is realized by a short FFT, short guard intervals and by compensating the remaining ISI/ICI by means of a special equalizer compensation (EC) matrix in the frequency domain. In this paper, a further useful application of the EC matrix is presented. Using the same matrix topology, we can show that narrowband interference, which is a severe problem in DMT and OFDM systems due to the limited selectivity of the FFT, can be nearly perfectly eliminated. The EC matrix possesses a sparse matrix topology and thus offers high spectral efficiency which is important for practical applications.