Reduced-PAPR Code Allocation Strategy for MC-CDMA Transmissions

First, an approximate expression for the peak-to-average power ratio (PAPR) of a multi-carrier code-division multiple access (MC-CDMA) signal is analytically derived. Then, it is demonstrated that the PAPR of a MC-CDMA signal can be suitably reduced by resorting to a judi- cious strategy for the allocation of the signature codes. Based on such a result, a low-complexity implementation of the proposed strategy is presented and its performance gain over the random allocation strategy is numerically assessed in terms of PAPR and out-of-band emissions.