Applying OOK modulation to reduce the inter-carrier interference in OFDM

Orthogonal frequency division multiplexing (OFDM) has become one of the promising technologies for the next-generation communications systems to support high-speed high-quality digital transmission and reception. However, the frequency misalignment between transmitter and receiver results in the inter-carrier interference (ICI), which degrades the performance. In this paper, we propose to apply On-Off-Keying (OOK) modulation in OFDM to reduce the ICI. The analysis shows that both spectral efficiency and energy efficiency can be improved in the proposed OFDM system. The analysis of symbol error rate (SER) is also provided. Simulation results show that when the ICI is significant, the SER is improved in the proposed OFDM system due to the ICI reduction resulting from the imposed OOK modulation.