PAPR Reduction Techniques for MC-CDMA System

Abstract

A complex pseudo-random (PN) sequence is proposed and used in a Multi-carrier Code Division Multiple Access (MC-CDMA) system. The correlation properties of this proposed PN-sequence are examined, illustrated, and compared with the well-known Walsh and Gold sequences. The Peak-to-Average Power Ratio (PAPR) properties of signals in an MC-CDMA system with complex PN-sequence are examined. Also, techniques such as clipping based on symbol statistics and improved Partial Transmit Sequence (PTS) are used for PAPR reduction in the MC-CDMA system. Numerical results show that the proposed complex PN-sequence exhibits good correction properties and the PAPR performance of MC-CDMA system is a function of the PN-sequence and the PAPR reduction method used. It is shown that significant PAPR reduction can be attained using the clipping based on symbol statistics technique and it is controlled by the value of the clipping factor (a) used in the system. In addition, when the improved PTS technique is applied for PAPR reduction in the MC-CDMA system, a PAPR reduction of nearly 4. 6 dB can be achieved compared to the system without this technique.