Performance Analysis of Selective Mapping in Underwater Acoustic Orthogonal Frequency Division Multiplexing Communication System

Power Amplifiers (PAs) play a vital role in mobile communication. However, their inherent nonlinearity can lead to issues such as unwanted radiation, interference with neighboring channels, and distortion within the desired frequency range. To address these problems, PAs are typically operated at a lower power level than their saturation point, sacrificing power efficiency to improve Error Vector Magnitude (EVM) performance. Consequently, more than 70-80% of the DC power is wasted as heat. This inefficiency necessitates the exploration of techniques to enhance PA efficiency while maintaining acceptable linearity and performance. Digital Pre-Distortion (DPD) is a useful technique to linearize PAs. DPD allows affordable nonlinear PAs to function with minimal distortion in their nonlinear operating regions. This results in amplified signals with increased power output and improved power efficiency. Using nonlinear functions, the output signal of the PA can be linearized, mitigate distortions, and be effectively optimized. When using various operating channels and varying time, temperature, and PA nonlinearity, the DPD must adjust. In order to increase the power efficiency of 5G systems, DPD-enabled systems are inculcating with adaptive DFT-s-OFDM employed 5G physical layer along with the Crest Factor Reduction (CFR) algorithm.

Section: Introductionmentioning

confidence: 99%

Power Amplifier Optimization for M2M Node using DPD and Hybrid DFT-s-OFDM with CFR

Sharma,

Kumar Arya,

Kumar

2023

An Intelligent Detoxification Function of Liver Algorithm-Partial Transmit Sequence (IDFLA-PTS) for the Reduction of Peak to Average Power Ratio in Underwater Acoustic OFDM Communication

Chen

Raza

Ali

et al. 2022

Intelligent algorithms in artificial intelligence have brought several benefits to digital signal processing. The boom in machine learning and intelligent systems provides new perspectives and methods to solve many research problems in Underwater Acoustic (UWA) Orthogonal Frequency Divisional Multiplexing (OFDM) communication. Partial transmit sequence is a tremendous technique for the mitigation of high Peak-to-Average Power Ratio (PAPR) in OFDM communication systems, but finding the optimum phase factors has still a few problems. In this paper, a Partial Transmit Sequence (PTS) based on an Intelligent Detoxification Function of Liver Algorithm-Partial Transmit Sequence (IDFLA-PTS) is proposed for the mitigation of PAPR in the UWA OFDM communication systems. This algorithm reduces the PAPR and the complexity of the proposed UWA OFDM model. The IDFLA-PTS is also compared with the Genetic Algorithm-Partial Transmit Sequence (GA-PTS). Besides this, the Bit Error Rate (BER) performance of the IDFLA-PTS is shown when a High Power Ampliﬁer (HPA) is used for the BELLHOP channel model. The experimental results of the proposed IDFLA-PTS method achieved nearly optimum results with fair complexity as compared to GA-PTS and boosted the BER performance.

Analysis of Multiple Input Multiple Output-Orthogonal Frequency Division Multiplexing with Dynamic Optimal Power Allocation

Srinivasulu,

Kumar

2024

Multiple Input Multiple Output (MIMO) is a technology that combines multiple antennas and Orthogonal Frequency Division Multiplexing (OFDM) modulation to increase the data rate and spectral efficiency of wireless communication systems. Equalization problems are one of the key issues with MIMO-OFDM systems, which are caused by multiple antennas and subcarriers. Optimal Power Allocation (OPA) in MIMO-OFDM is a critical component for achieving high spectral efficiency and improving the overall performance of the system. OPA refers to the process of allocating power to the different subcarriers and antennas in MIMO-OFDM systems in an optimal way. This study proposes the Dynamic OPA (DOPA) algorithm for MIMO-OFDM systems to dynamically adjust power allocation based on the changing channel conditions and reduce pilot contamination issues. This approach allocates more power to subcarriers and antennas with better channel conditions and less power to subcarriers and antennas with worse channel conditions. DOPA in MIMO-OFDM systems is necessary to maximize data rates, minimize interference, improve system capacity, and reduce power consumption. Simulation results showed that the proposed MIMO-OFDM-DOPA had reduced bit error rates, mean square error, and transmitter power and increased energy efficiency and capacity compared to existing state-of-the-art methods.