scholarly journals An Efficient Carrier Synchronization Scheme for Demodulation Systems

Electronics ◽  
2021 ◽  
Vol 10 (23) ◽  
pp. 2942
Author(s):  
Wanru Hu ◽  
Zhugang Wang ◽  
Ruru Mei ◽  
Meiyan Lin
Keyword(s):  
Carrier Frequency ◽  
Communication Systems ◽  
Carrier Frequency Offset ◽  
Initial Conditions ◽  
Signal To Noise Ratio ◽  
Linear Interpolation ◽  
Hardware Complexity ◽  
Carrier Synchronization ◽  
Symbol Rate ◽  
Synchronization Scheme

A simple data-aided carrier synchronization scheme is proposed for variable modulation (VM) communication systems under the initial conditions of a low signal-to-noise ratio (SNR) and normalized carrier frequency offset (CFO) symbol rate of 20%. The proposed carrier synchronization scheme is simplified into two steps; a reconfigurable L&R (RLR) algorithm and pilot-aided (PA) phase linear interpolation algorithm is applied for carrier frequency recovery (CFR) and carrier phase recovery (CPR), respectively. Furthermore, the autocorrelation values of multi-pilot blocks are superimposed to improve the accuracy of the CFR algorithm, and the algorithm formulas are decomposed and modularized to simplify the implementation complexity of the RLR algorithm. Simulation results show that the RLR algorithm can track and lock the CFO up to a 33.2% symbol rate and reduce the CFO to 0.024%. The bit error rate (BER) performance of the carrier synchronization scheme almost coincides with the theoretical curve results. Comparison of hardware complexity shows that the multiplication resource consumption can be reduced by at least 72.47%.

scholarly journals INTER CARRIER INTERFERENCE AND SIGNAL TO INTERFERENCE RATIO OF VARIOUS PULSE SHAPING FUNCTIONS USED IN OFDM SYSTEM WITH CARRIER FREQUENCY OFFSET

2012 ◽  
pp. 68-71
Author(s):  
SHANKAR AENAGANDULA ◽  
ASHOK KUMAR ◽  
SRINIVAS K ◽  
MONIKA NANDA
Keyword(s):  
Carrier Frequency ◽  
Orthogonal Frequency Division Multiplexing ◽  
Pulse Shaping ◽  
Carrier Frequency Offset ◽  
Signal To Noise Ratio ◽  
Frequency Offset ◽  
Performance Comparison ◽  
Intercarrier Interference ◽  
Ofdm Systems ◽  
Ofdm System

Orthogonal Frequency Division Multiplexing (OFDM) is the important modulation of choice for fourthgeneration broadband multimedia wireless systems. This paper is focused on the problem of reducing the intercarrierinterference (ICI) and signal to noise ratio in the transmission over OFDM using various pulse shaping methods. Here we have performed a detailed performance comparison of various pulse shaping functions used in OFDM System with Carrier Frequency Offset. They appear to be suitable for transmission in OFDM systems with carrier frequency offset. The results obtained by analysis show that the performance improvement over conventional pulse shapes, are significant for reducing average intercarrier-interference (ICI) power and increased ratio of average signal power to average ICI power (SIR).

scholarly journals PERFORMANCE EVALUATION OF SINGLE CARRIER FREQUENCY DOMAIN EQUILIZER (SC-FDE) OVER IMPULSIVE NOISE CHANNEL

2019 ◽  
Vol 11 (2) ◽  
pp. 270-277
Author(s):  
Hussein Abdullah Leftah ◽  
Husham Lateef Swadi
Keyword(s):  
Frequency Domain ◽  
Carrier Frequency ◽  
Communication Systems ◽  
Impulsive Noise ◽  
Signal To Noise Ratio ◽  
High Signal ◽  
Signal To Noise ◽  
Single Carrier ◽  
Noise Ratio ◽  
Error Floors

Impulsive noise is considered as one of the major source of disturbance in the state-of-the-art multicarrier (MC) communication systems. Therefore, several techniques are being constantly proposed to eliminate the effect of such noise. In this work, a time domain matrix interleaved is compiled with a single carrier frequency domain equalizer (SC-FDE) is proposed to reduce the deleterious effects of impulsive noise. A mathematical model for the proposed scheme is also presented in this paper. Simulation results show that the proposed technique superiors the interleaved multicarrier system where the proposed scheme can completely avoid the error floors not only at high signal-to-noise ratio (SNR) but also at heavily distributed impulsive noise. The bit-error-rate (BER) of the alternative proposed scheme decreases as the signal-to-noise ratio (SNR) increases whereas the BER of the standard system suffers from error-floors with a constant BER at about 10-3 for about 8 dB SNR for medium and heavily impulsive noise.

Compressed Sensing Based Blind Carrier Frequency Offset Estimation for OFDM System

2013 ◽  
Vol 756-759 ◽  
pp. 1894-1897 ◽  
Author(s):  
Gang Yang ◽  
Hua Xin Yu ◽  
Xiao Fei Zhang
Keyword(s):  
Compressed Sensing ◽  
Carrier Frequency ◽  
Orthogonal Frequency Division Multiplexing ◽  
Carrier Frequency Offset ◽  
Signal To Noise Ratio ◽  
Estimation Algorithm ◽  
Frequency Offset ◽  
Ofdm Systems ◽  
Carrier Frequency Offset Estimation ◽  
Sensing Model

In this paper, we address the problem of carrier frequency offset (CFO) estimation for Orthogonal Frequency Division Multiplexing (OFDM) systems. This paper links CFO estimation problem in OFDM systems to the compressed sensing model. Exploiting this link, it derives a compressed sensing-based CFO estimation algorithm. The proposed algorithm has better CFO estimation performance than ESPRIT method with lower signal-to-noise ratio (SNR). Simulation results illustrate performance of this algorithm.

Study of the OFDM System Carrier Synchronization Technology

2014 ◽  
Vol 513-517 ◽  
pp. 2772-2774
Author(s):  
Wen Bin Wang ◽  
Dao Yuan Liu ◽  
Yu Qin Yao
Keyword(s):  
Carrier Frequency ◽  
Carrier Frequency Offset ◽  
Estimation Algorithm ◽  
Frequency Offset ◽  
Frequency Synchronization ◽  
Frequency Offset Estimation ◽  
Ofdm System ◽  
Carrier Synchronization ◽  
Carrier Frequency Offset Estimation ◽  
Primary Problem

The OFDM system modulates signal by using a plurality of spectrum aliasing orthogonal sub-carriers, so it is extremely sensitive to carrier frequency offset, and any tiny frequency offset may destroy the orthogonality of the sub-carriers, thereby seriously affecting the performance of the system. So carrier frequency offset is the primary problem for the OFDM technology, and in recent years it has also become a focus for researchers. Accurate frequency synchronization is the precondition for the OFDM system to work properly. The main purpose of this paper is to seek a more reliable and viable carrier frequency offset estimation algorithm on the results of previous studies.

scholarly journals Modulation Classification of MFSK Modulated Signals Using Wavelet Decomposition

2018 ◽  
pp. 36-40
Author(s):  
Burcu Baris ◽  
Damla Gurkan Kuntalp ◽  
Mehmet Emre Cek
Keyword(s):  
Carrier Frequency ◽  
Communication Systems ◽  
Wavelet Decomposition ◽  
Clustering Algorithm ◽  
Signal To Noise Ratio ◽  
Classification Performance ◽  
Discrete Wavelet ◽  
Modulation Classification ◽  
Frequency Range ◽  
Intelligent Communication

In this study,a wavelet decomposition based method is proposed for determining the modulation type of the incoming signal to the receiver which is one of the important problems in intelligent communication systems. In this method, it is aimed to design the transmitted signal for determining the type of Mary FSK modulated signal and to detect the energy in each frequency band by using Discrete Wavelet Transform (DWT). For this, standard deviations in the lower bands are as features. In order to evaluate the performance of the classifier, simulation studies have been performed at different signal-to-noise ratio (SNR) levels. When the results for different frequency settings, i.e. carrier frequency and frequency range, it is seen that the classifier using the K-means clustering algorithm has a higher correct classification performance than the results reported in the literature when the suitable carrier frequency and frequency range are selected.

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