On the Nonlinear Companding Transform for Reduction in PAPR of MCM Signals

An Overview of Peak-to-Average Power Ratio Reduction Techniques for OFDM Signals

“…The authors proved that this proposed piecewise linear companding scheme can reduce companding distortion and PAPR effectively. Besides, uniform companding [15], logarithmic companding and hyperbolic tangent companding transforms [18], with proper companding coefficients, were used in the literature to reduce PAPR.…”

Companding schemes based on transforming signal statistics into trigonal distributions for PAPR reduction in OFDM systems

“…The block diagram of a typical companded OFDM system [12] is shown in Figure 1. First, the input bit stream is modulated by quadrature amplitude modulation (QAM) or phase shift keying (PSK) to form frequency domain signal S k , where k = 0, 1, .…”

“…Figure 6 depicts the profiles of the proposed four companding transforms and other three companding transforms, C 1 (·), C 2 (·) in [12], and linear companding transform with two inflexion points in [11]. In order to keep original signals and companded signals at the same average power level, the proposed companding transforms compress signals with large amplitude and expand signals with small amplitude.…”

Distinctive Approach to Design Tree in Wavelet Packet based OFDM System

“…Various techniques in [1][2][3][4][5][6][7][8][9], have already been proposed in literature to reduce PAPR of original OFDM system such as Partial Transmit Sequence (PTS) [2], Selective Mapping (SLM) [3], Clipping [4], Coding [5], Hadamard Transform [6], Tone Reservation and Tone Injection [7], Interleaving [8], and Nonlinear Companding Transform [9] etc. All these systems use Fast Fourier Transform (FFT) as signal transformation with different modulation techniques.…”