A multichannel transceiver system for asymmetric digital subscriber line service

The authors study the performance of a multichannel modulation technique for the contemplated data service known as asymmetric digital subscriber lines (ADSLs). It was found that over all unloaded North American subscriber lines in the test set, a unidirectional 1.536-Mb/s data rate service from the end-office to the customer premises can be easily achieved on a single twisted pair at an error rate of 10^-7 . The dominant line impairments studied include far-end crosstalk from basic-rate access integrated services digital network (ISDN), spill-over basic rate access ISDN signal, and additive white Gaussian noise (AWGN). It was found that the proposed ADSL service can coexist with the previously existing baseband service on the same twisted pair