We present a high density single carrier 1024 QAM transmission scheme for digital cable TV systems. A transmission of approximately 50 Mbps within a single 6 MHz channel and with a higher spectrum efficiency than a conventional digital cable modem, is achieved. For evaluating an equalizer performance in a cable TV channel, we carry out computer simulations before hardware implementation of a 1024 QAM receiver. The BER result of a prototype 1024 QAM modem without forward error correction is 10-4at a CN ratio of 37 dB with Gaussian noise. The implementation loss is less than 1 dB. In addition, we experimentally investigate robustness against interference and the influence of nonlinear amplification of a 1024 QAM signal.
