Design studies for ASIC implementations of 28 GS/s optical QPSK- and 16-QAM-OFDM transceivers

Abstract

We designed at the register-transfer-level digital signal processing (DSP) circuits for 21.8 Gb/s and 43.7 Gb/s QPSK- and 16-QAM-encoded optical orthogonal frequency division multiplexing (OFDM) transceivers, and carried out synthesis and simulations assessing performance, power consumption and chip area. The aim of the study is to determine the suitability of OFDM technology for low-cost optical interconnects. Power calculations based on synthesis for a 65 nm standard-cell library showed that the DSP components of the transceiver (FFTs, equalisation, (de)mapping and clipping/scaling circuits) consume 18.2 mW/Gb/s and 12.8 mW/Gb/s in the case of QPSK and 16-QAM respectively.