Equalization technology and Quantization analysis for Data-converter Based PAM4 SerDes Link

This paper constructed the distribution function of input noise at the receiver side and quantization noise for 25 Gb/s data-converter based PAM4 (4-level Pulse Amplitude Modulation) serial link. In order to reflect realistic performance, the effect of both noise on the equalization performance were analyzed at first. Then, the FFE’s location and the tradeoff between quantization resolution of data converter and FFE tap were studied in detail. Simulation results show that Rx FFE architecture can outperform Tx FFE for a high Gaussian noise environment. And for Rx FFE architecture, more-tap DFE can effectively suppress quantization noise and make a great tradeoff with the quantization resolution of analog-to-digital converter (ADC), which can be suitable for a high-noise and low-quantization transmission link.