An iterative structure for synthesizing symmetric functions using quantum-dot cellular automata

In recent years, majority-logic received significant attention as a synthesis approach for large Boolean functions. This logic is easily implemented in Quantum-dot cellular automata (QCA) technology which is emerging as an alternative to CMOS technology. In fact, majority logic gate serves as the basic logic unit in the digital design of QCA circuits. This paper introduces a synthesis technique for implementing totally symmetric Boolean functions using majority logic. First, a simple regular module is designed to synthesize unate symmetric functions. The structure uses 3-input majority gates. General symmetric Boolean functions are then realized following a unate decomposition method. We study the synthesis of some well known benchmark symmetric functions using the proposed method. Comparison with existing synthesis approaches confirms the efficacy of our method.