A PAPR Reduction of MC-DS-CDMA Signal by Spectrum Phase Control (SPC) Method

Multi-carrier direct-sequence code division multiple access (MC-DS-CDMA) system is very attractive in high-bit-rate wireless communication because of the good bandwidth efficiency, robustness to the frequency selective multi-path fading. However, MC-DS-CDMA inherently has a major drawback, which is the high peak-to-average-power ratio (PAPR) problem. In this paper, we propose a new efficient PAPR reduction method based on the spectrum phase control (SPC). The proposed method rotates the phase of each DS-CDMA spectrum for reducing the PAPR. Also, it uses the disjointed-spectral characteristic of MC-DS-CDMA signal in order to insert the tones for conveying the side information of SPC. The simulation results show the PAPR reduction capability and the improvement in nonlinear environment. Proposed method can reduce more than 4.6dB PAPR reduction of MC-DS-CDMA signal, and total power degradation can be improved by about 3.42 dB when TWTA (traveling wave tube amplifier) is used.