Abstract
A 1024 QAM modem with high amplitude density and large capacity for cable TV transmission is presented. About 50Mbps, higher spectrum efficiency than conventional digital cable modem, in a single 6MHz channel is achieved. The BER performance of a prototype 1024 QAM modem without Forward Error Correction is 10^<-4> at the CN ratio of 37dB with Gaussian noise. The implementation loss is less than 1dB. The distortion effect induced on a 1024 QAM in the presence of a nonlinear amplifier is also evaluated.
