A VLSI architecture design for dual-mode QAM and VSB digital CATV transceiver

In this paper, a transceiver VLSI architecture is proposed for high speed d igital CATV modems, which can perform both the QAM and the VSB transmission s [1], [2]. The proposed architecture of all-digital dual-mode QAM/VSB rece iver consists of digital AGC, digital demodulator, fractionally spaced blin d equalizer and DFE, digital carrier recovery, and symbol timing recovery. Finite word-length simulation results show that the proposed architecture c an achieve an SNR 29 dB for both the 64-QAM mode and 8-VSB mode when the 10 bit ADC input signal SNR is 36 dB, and there are +/-6 kHz of carrier frequ ency offset, +/- 110 ppm of symbol rate offset, and -82 dBc carrier phase-j itter at 10 kHz away from the nominal carrier frequency.