Design and measurement of a variable-rate Viterbi decoder in 130-nm digital CMOS

Abstract

This paper discusses design and measurements of a flexible Viterbi decoder fabricated in 130-nm digital CMOS. Flexibility was incorporated by providing various code rates and modulation schemes to adjust to varying channel conditions. Based on previous trade-off studies, flexible building blocks were carefully designed to cause as little area penalty as possible. The chip runs down to a minimal core supply of 0.8 V. It turns out that striving for more modulation schemes is beneficial in terms of power consumption once the price is paid for accepting different code rates viz. radices in the trellis and survivor path units.

New symmetric and planar designs of reversible full-adders/subtractors in quantum-dot cellular automata

“…Quantum-dot Cellular Automata (QCA) as a well-known technology is able to replace devices based on FET (Field Effect Transistor) on nano-scale [3][4][5]. Promising size density of several orders of magnitude smaller than CMOS, fast switching time and extremely low power, has caused QCA to become a very interesting topic of researches [6][7][8]. A QCA cell consists of four dots and two identical electrons.…”