A computationally efficient adaptive transceiver for high-speed digital subscriber lines

The feasibility of implementation of a multichannel inverse discrete Fourier transform/discrete Fourier transform transceiver for crosstalk-limited carrier-serving-area subscriber loops is demonstrated. This transceiver can provide reliable T1 transmission in the presence of crosstalk noise on most loops. The complexity of the design is examined in terms of speed or computing power. The authors also note several practical advantages of this system: channel response estimation during call initialization, simplicity of the transmitter, short-length equalizer, and absence of error propagation. It is concluded that the complete receiver can be implemented with under 40 MIPS of computing power, using a fairly high signaling rate of 640 kHz, on conventional DSP chips. One bottleneck in the receiver is the Viterbi decoder, which may take around 1000 MIPS using a standard DSP chip.<<ETX>>