PAPR Reduction Using Cyclic-Selective Mapping with Delayed Correlation in Time Domain

Abstract

In this paper, a peak-to-average power ratio (PAPR) reduction scheme without side information (SI) is propossed. Cyclic-selective mapping (cyclic-SLM) has been applied to reduce the PAPR of a transmit orthogonal frequency division multiplexing (OFDM) signal. The cyclic-SLM generates a signal candidate by combining an original signal and its cyclic shifted signal. The Cyclic SLM requires side information regarding the cyclic shift to recover the signal while it will reduce the throughput of a wireless OFDM system. The propossed scheme applies delayed correlation based estimation to omit the transmision of the SI. In the receiver side, the amount of the cyclic shift is estimated with exploiting the correlation between a guard interval sequence and a received signal. Numerical results show that the cyclic-SLM with the delayed correlation (DC) provides significant PAPR reduction while it realizes the accuracy of the shift estimation close to 100 % at E b /N0 of 8 dB. It also achieves the PAPR that is equivalent to the conventional SLM and the bit error rate degradation is slightly different from that with perfect shift estimation.Index Terms-Peak-to-average power ratio (PAPR), selective mapping (SLM), cyclic-SLM, delayed correlation

Estimation of Cyclic Shift with Delayed Correlation and Matched Filtering in Time Domain Cyclic-SLM for PAPR Reduction

“…The block diagram of the TDC-SLM scheme is shown in Figure 1. The cyclically shifted signal in the TDC-SLM is given as$\begin{array}{c}T3x_f\left[n,{\mathrm{\Delta }}_d\right]\\ =\left\{\begin{array}{cc}x\left(N-{\mathrm{normal\Delta }}_d+n\right),\hfill & -N_{\mathrm{normalG}\mathrm{normalI}}\le n\le {\mathrm{normal\Delta }}_d-\mathrm{normal1},\hfill \\ x\left(n-{\mathrm{normal\Delta }}_d\right),\hfill & {\mathrm{normal\Delta }}_d\le n\le N-\mathrm{normal1},\hfill \end{array}\right.\end{array}$where x [ n ] is the OFDM signal in the time domain at the time index of n , N GI is the GI length, x f [ n , Δ d ] is the SC that is generated by cyclically shifting the OFDM signal by Δ d , Δ d is the amount of the cyclic shift for the d th SC, and Δ d ∈ { Cδ }, where C is an integer [11, 12]. The resolution of the cyclic shifts, δ , has to be large enough for accurate estimation of the cyclic shifts in a receiver.…”

“…However, this scheme requires embedding the SI in transmit symbols. In the scheme presented in [11], time domain cyclic-SLM with delayed correlation (DC) is applied to reduce a PAPR and to estimate the amount of a cyclic shift at the receiver without SI transmission. Nevertheless, there is a tradeoff between the amount of PAPR reduction and the BER.…”

Out-of-Band Power Suppression for Cyclic SLM with Delayed Correlation and Matched Filter

“…The possible phase vector was prepared at the receiver side and an SI index was embedded in transmitted signal which decreased the throughput of the OFDM systems. In [13], the cyclic-SLM with delayed correlation (DC) was proposed to reduce the PAPR and estimate the cyclic shift at the receiver side. The proposed solution had trade off between PAPR reduction and bit error rate (BER).…”

“…The proposed solution had trade off between PAPR reduction and bit error rate (BER). In [14], a method to improve the performance of the previous scheme [13] was proposed. It implemented cyclic-SLM with 3 branches and appended a matched filter (MF) with Barker code sequences to estimate the cyclic shift at the receiver side.…”

A Quick Convergence Active Constellation Extension Projection onto Convex Sets Algorithm for Reducing the PAPR of OFDM System

“…These methods can be classified into three categories: distortion techniques like clipping [2] and companding [3], distortion-free techniques like Selective Mapping (SLM) [4,5,6,7] and Partial Transmit Sequence (PTS) [8], and average-power-increasing techniques like Active Constellation Extension (ACE) [9,10,11,12] and Tone Reservation (TR) [13,14,15].…”