PAPR Reduction in OFDM Systems Using Modified PTS Algorithm and Peak Windowing

Orthogonal Frequency Division Multiplexing (OFDM) has emerged as one of the front bearers of high data rate in present as well as evolving wireless technologies such as 3G, 4G, LTE, LTE+, IEEE 802.11 (WLANs), Wi-Fi, Wi-Max  etc. One of the major challenges encountered by OFDM systems is high Peak to Power Ratio (PAPR). Several PAPR reduction techniques have been investigated but the search for more efficient algorithms has remained an active area of research. The reason being the proportional dependence of PAPR on the number of sub carriers in OFDM systems (N) or in worst cases on the square of the number of sub-carriers (N)2[1],[2]. The Partially Transmitted Sequences (PTS) algorithm has been one of the most promising techniques for PAPR reduction exhibiting substantial PAPR reduction capability [2]. The flipside remains the escalation in computational complexity with increase in length of phase sequences and partitioning of data blocks [9]. Here we propose a modified PTS technique with local peak windowing that shows greater PAPR reduction capability without needing to increase the length of phase vector or partitioning of data blocks. In this paper, different windowing functions are employed in conjugation with PTS and their results are compared to show the efficacy of the proposed algorithm.