Dynamic Guard-Band Features of the IBM zNext System
Tobias Webel, Phillip Restle, et al.
ISSCC 2025
This brief presents a 2-lane discrete multitone (DMT) wireline receiver (RX) with a far-end crosstalk (FEXT) cancellation and its implementation on the ZCU111 RFSoC evaluation board for real-time functional verification. The RX datapath is implemented with the 64-parallel 128-tap multi-path delay-feedback (MDF) fast Fourier transform (FFT) to optimize resources and throughput. The multiple-input, multiple-output (MIMO) frequency-domain equalizer (FDE) compensates both channel insertion loss (IL) and FEXT based on coefficients computed from an on-chip pilot-assist channel estimation (CHEST). The platform includes a programmable logic (PL) for a DMT digital signal processor (DSP) running at 32 MHz, 2.048 GS/s data converters, and intersymbol interference (ISI)/FEXT board. This system enables the reflection of a realistic hardware impairment and real-time transceiver (TRX) operation with a quick bit error rate (BER) test. The measurement demonstrates that the MIMO DMT significantly improves a BER from 1.0E-2 to 5.8E-7 when the FEXT is canceled for a channel exhibiting 15 dB of IL and 10 dB of IL-to-crosstalk ratio (ICR) at Nyquist frequency.
Tobias Webel, Phillip Restle, et al.
ISSCC 2025
Alessandro Cevrero, Ilter Ozkaya, et al.
ISSCC 2019
Marc Taubenblatt, Asser Tantawi
IPDPSW 2022
Marcelo Amaral, Tatsuhiro Chiba
Kubecon + CloudNativeCon NA 2023