A 56-Gb/s DAC/ADC-Based Multicarrier Transceiver With TX Polar DSP and RX MIMO-DSP for >40-dB Loss Channel

This article presents a DAC/ADC based multicarrier transceiver fabricated in a 22-nm FinFET technology. The multicarrier signaling scheme utilizes orthogonally spaced carriers for spectral efficient band spacing and exhibit jitter robustness compared to conventional baseband pulse amplitude based signaling. The transmitter has a polar DSP to generate the equalized codes driving the 7b phase DACs, and 7b amplitude DACs with 2b predistortion to yield 1.2Vppd swing. The multicarrier receiver front-end ADC outputs are equalized with a MIMO DSP backend to compensate for the inter-symbol interference and inter-channel interference. The measured transceiver at 56Gb/s through a 40.8dB loss at 14GHz channel showed a jitter tolerance of up to 1.21psrms at BER<10-4 with 7.82pJ/bit power efficiency.