A low complexity code selection method for peak to average power ratio reduction in MC-CDMA

The PAPR problem is one of the main drawbacks in MC-CDMA system. Variable Code Sets (VCS) can improve the PAPR property of the MC-CDMA signals. However, VCS technique requires an exhaustive search over the combinations of allowed spreading code sets. When the number of active users increases, the search complexity will increase exponentially. In this paper, we propose a low complexity VCS (LC-VCS) method to reduce the computational complexity. The basic idea of LC-VCS is to derive new signals using the relationship between candidature signals. Simulation results show that the proposed approach can reduce PAPR with lower computational complexity. In addition, it can be blindly received without any side information due to the orthogonality of spreading codes.