Hybrid Zadoff‐Chu and multilateral piecewise exponential companding transform–based PAPR reduction technique in OFDM systems

Abstract

SummaryThe orthogonal frequency‐division multiplexing (OFDM) is a multicarrier modulation system that is used to transmit the large volume of data to the receiver. Reducing the peak‐to‐average power ratio (PAPR) in OFDM system is one of the demanding and crucial task in recent days. For this reason, various precoding and companding mechanisms are developed in the traditional works, but it remains with the limitations of increased complexity, reduced performance, and nonlinear distortion. The reduction of PAPR is achieved by minimizing the companding distortion with the enhancement of the bit error rate (BER) performance significantly. Then, in order to avoid clipping in OFDM, a multilateral piecewise exponential companding transform (MPECT) method has been utilized rather than using piecewise exponential companding transform (PEC) where PAPR is getting reduced. The OFDM is very sensitive to synchronizing error. To overcome this sensitivity, employ the Zadoff‐Chu sequence to carrier frequency offsets. Zadoff‐Chu matrix transform (ZCMT) has numerous merits among the other ODFM systems such as the improvement in the performance of the channels that are fading away and provides an ideal periodic autocorrelation and a constant magnitude periodic cross correlation. Both of these techniques provide improvement in the ODFM systems. To get more efficiency, this paper aims to develop a hybrid technique by integrating the ZCMT and MPECT techniques for reducing the PAPR in OFDM systems. Further, convolutional encoding is applied for better BER and PAPR. The simulation results of the proposed ZCMT‐MPECT technique are evaluated and compared with the conventional OFDM and other precoding methods.

A Novel Hybrid Precoding-Companding Technique for Peak-to-Average Power Ratio Reduction in 5G and beyond

“…The authors in [ 34 ] showed that Zadoff–Chu Transform hybridized with -law (ZCT- ) is better than WHT- from PAPR reduction point of view. The authors in [ 35 ] hybridized ZCT with the Piecewise Exponential Companding technique. However, the solution is impractical because it uses inflection point and side information data as PLC.…”

“… Many precoding-companding techniques [ 26 , 29 , 31 , 36 , 37 ], are not compared with any previous works. HPA was neglected in the models [ 22 , 26 , 27 , 28 , 30 , 31 , 33 , 34 , 35 , 36 , 37 ], although HPA is the source of nonlinear distortion. The authors in [ 22 , 26 , 28 , 30 , 31 , 34 , 36 , 37 ] have not considered Rayleigh channel.…”

“…HPA was neglected in the models [ 22 , 26 , 27 , 28 , 30 , 31 , 33 , 34 , 35 , 36 , 37 ], although HPA is the source of nonlinear distortion.…”

A novel ant colony optimization algorithm for PAPR reduction of OFDM signals

“…2 Thus, the PAPR should be reduced to eliminate the nonlinear distortion and improve the performance of bit error rate (BER). 3,4 Many PAPR reduction approaches have been reported in the previous studies, such as clipping and filtering, 5 nonlinear companding, 6 coding, 7 tone reservation (TR), 8 ton injection (TI), 9 precoding-based methods, 10,11 partial transmit sequence (PTS), 12,13 and selective mapping (SLM). 14 The extensive research on PAPR reduction methods is also surveyed.…”

“…5 In the companding approach, the OFDM signal is applied to a companding function at the transmitter side, and a decompander is applied to recover the original signal at the receiver end. 6 In the coding technique, a specific codeword is used before modulation to minimize the PAPR. 7 In TR and TI techniques, a subset of tones is reserved by transmitter and receiver to reduce the PAPR.…”