An Efficient ACE Scheme for PAPR Reduction of OFDM Signals with High-Order Constellation

Abstract

Orthogonal Frequency Division Multiplexing 
(OFDM) is a highly efficient and robust modulation 
technique widely adopted in modern wireless 
systems such as 5G, LTE, Wi-Fi, and DVB-T2. Its 
ability to combat multipath fading and support high 
data rates has made it a fundamental component of 
next-generation communication systems. However, a 
major drawback of OFDM is its inherently high 
Peak-to-Average Power Ratio (PAPR), which can 
severely degrade system performance by forcing 
power amplifiers to operate inefficiently and 
introducing distortion in transmitted signals. To 
address the PAPR challenge, several techniques 
have been explored, including Clipping and 
Filtering, Selective Mapping (SLM), Partial 
Transmit Sequence (PTS), and Active Constellation 
Extension (ACE). Among them, ACE has shown 
significant potential due to its ability to reduce PAPR 
without transmitting side information and without 
introducing 
in-band distortion. Despite its 
effectiveness, traditional ACE methods suffer from 
high computational complexity, slow convergence, 
and limited adaptability to high-order modulation 
schemes such as 256-QAM and 1024-QAM. The 
results demonstrate that EPOCS-ACE achieves 
superior performance compared to traditional ACE, 
SLM, and PTS techniques, making it highly suitable 
for real-time and power-sensitive applications in 5G 
and future wireless communication systems. With its 
balance 
of 
complexity, 
performance, 
and 
adaptability, the proposed scheme contributes 
meaningfully to the ongoing evolution of energy efficient and high-speed digital communication 
systems.