Zhou, R.; Mavretic, A.; Boston University, College of Engineering (International Foundation for Telemetering, 1986-10)
      A general tendency in the digital communication systems is toward multi-level signalling in order to increase the information rate over a fixed bandwidth channel. Multiple valued logic circuits hold the promising potential for this application. including digital modulation, signal power spectrum shaping and coding techniques. Thispaper will present a novel design of quaternary modular adder circuit using multi-semiconductor technology — BI-CMOS process. This circuit demonstrates many advantages in improving noise margin and speed as well as in reducing transistor counts and chip areas. Some comparison with its binary counterpart and SPICE simulation results will also be given. Due to growing interest in multiple-level signalling combining with multiple-valued logic technology in digital communication systems, this paper will also discuss the application of modular adder in correlative coding techniques for spectral shaping. where quaternary modular adder performs efficiently in encoding input signal of non binary form at the transmitting end and in reconstructing the original data input at the receiving end. It also can allieviate the pin and interconnection requirements for equivalent information transfer.