A novel signaling technique for high-speed wireline backplane transceiver: Four phase-shifted sinusoid symbol (PSS-4)

This paper proposes a novel four phase-shifted sinusoid symbol (PSS-4) signaling technique to relief high-speed wireline backplane transceiver to reduce large intersymbol interference. The four-level pulse amplitude modulation (PAM-4) and other existing amplitude modulation techniques have been widely used to simplify transceiver equalization design for highly dispersive channels. Unfortunately, PAM-4 and other methods reduce the symbol rate at the expense of signal-to-noise ratio (SNR) and thus limit the bit-error-rate (BER). The proposed PSS-4 signaling avoids large SNR degradation by using four phase-shifted symbols to transmit two-bit data. The experimental results show that with sufficient equalization, our PSS-4 signaling can achieve over 2 dB larger SNR than the conventional non-return-to-zero (NRZ), Duobinary, and PAM-4 signaling techniques. In addition, for a target BER of 1E-12, the proposed PSS-4 signaling has the largest sampling range comparing against existing backplane signaling techniques. Furthermore, compared with NRZ-based backplane transceiver, PSS-4 signaling reduces the equalizer power consumption by 24%.