Title :
Performance enhanced adaptive equalizers for multicarrier channels
Author :
Strait, Jeffrey C.
Author_Institution :
Adv. Dev. Center, 3Com Corp., Grass Valley, CA, USA
Abstract :
Multicarrier modulation techniques are increasingly used in high bandwidth xDSL transceivers. Multicarrier quadrature amplitude modulation (QAM) systems offer an efficient method of maximizing the transmission bitrate over existing copper. The attenuation and crosstalk characteristics of the copper plant require careful equalization to realize the required bit error rate. Because this technique relies on the fast Fourier transform coupled with a cyclic redundant guard interval, the goal of equalization is not to exactly invert the channel characteristic, but to reduce the combined channel-equalizer effective impulse response length to less than or equal to some integer L, defined by the inclusion of the cyclic prefix in the transmitted sample sequence. This paper examines techniques to improve both the rate of error convergence of the adaptive equalizer and the residual inter-symbol interference of the system
Keywords :
adaptive equalisers; convergence; error statistics; fast Fourier transforms; intersymbol interference; quadrature amplitude modulation; telecommunication channels; transceivers; BER; FFT; QAM systems; adaptive equalizers; attenuation characteristics; bit error rate; crosstalk characteristics; cyclic redundant guard interval; effective impulse response length; error convergence rate; fast Fourier transform; high bandwidth xDSL transceivers; multicarrier channels; multicarrier modulation techniques; performance enhanced equalizers; quadrature amplitude modulation; residual ISI improvement; residual intersymbol interference; Adaptive equalizers; Attenuation; Bandwidth; Bit error rate; Bit rate; Copper; Crosstalk; Fast Fourier transforms; Quadrature amplitude modulation; Transceivers;
Conference_Titel :
Circuits and Systems, 1997. Proceedings of the 40th Midwest Symposium on
Conference_Location :
Sacramento, CA
Print_ISBN :
0-7803-3694-1
DOI :
10.1109/MWSCAS.1997.662183