This work presents a new signaling method operating based on a Nyquist-rate orthogonal pulse amplitude modulation (NOPAM) scheme for high-speed wireline communication systems. The proposed signaling approach provides a 2 bit/symbol throughput like PAM-4 signaling while requiring only three voltage levels for data transmission. Thus, it is less sensitive to non-idealities of the lossy interfaces in long/medium reach links. A transceiver (TRx) architecture using NOPAM signaling is presented and realization of its main blocks is described. A 56 Gbps NOPAM TRx using a medium-reach link with 20 dB loss at 14 GHz is modeled and simulated in MATLAB. Performance of the system is provided and compared with a conventional PAM-4 TRx, verifying the advantages of the proposed NOPAM signaling.