Non-continuous carrier-interferometry codes

Carrier interferometry (CI) codes have been proposed for multi-carrier systems, e. g., orthogonal frequency division multiplex (OFDM), which achieves higher transmission rate and lower peak to average power ratio (PAPR). In this paper, non-continuous carrier interferometry (NCI) codes have been constructed for the non-continuous multi-carrier systems. In the cognitive radio system such as IEEE 802.22, non-continuous OFDM is employed to avoid interference for spectrum holes. In this scheme, all the subcarriers within the spectrum holes are activated. Otherwise, the subcarriers are deactivated. This mechanism is quite suitable to involve NCI codes and formulate the NCI-OFDM system. Simulation results show that the NCI-OFDM system enjoys a wonderful transmission rate and low PAPR compared with the traditional NC-OFDM, which confirms that the NCI-OFDM is a promising transmission scheme for broadband cognitive radio systems.