scholarly journals On Narrowband Interference Suppression in TDCS with WFRFT Preprocessing

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Quan Wang ◽  
Xinxi Feng ◽  
Yuan Liang
Keyword(s):  
Bit Error Rate ◽  
Gaussian Noise ◽  
Fractional Fourier Transform ◽  
Additive White Gaussian Noise ◽  
Basic Function ◽  
Transform Domain ◽  
Narrowband Interference ◽  
Time Frequency ◽  
Relationship Coefficient ◽  
Ber Performance

We propose a modified transform domain communication system (TDCS) structure with weighted fractional Fourier transform (WFRFT) preprocessing over the channel with additive white Gaussian noise (AWGN) and narrowband interference (NBI). The majority of NBI can be removed by adding zeros to TDCS’s basic function (BF) amplitude vector at these subcarriers where strong NBI exists, and the corresponding residual NBI can be further greatly eliminated in time-frequency domain through WFRFT processing. To achieve the best bit error rate (BER) performance, we defineγas the normalised cross relationship coefficient between TDCS’s BF vector and residual NBI vector and prove that the corresponding WFRFTαoptcan be obtained by minimising the magnitude ofγ. Numerical simulations are conducted to evaluate the proposed system’s performance with regard to NBI suppression.

scholarly journals Design and Implementation of a Chaotic Scheme in Additive White Gaussian Noise Channel

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Nizar Al Bassam ◽  
Oday Jerew
Keyword(s):  
Bit Error Rate ◽  
Gaussian Noise ◽  
Chaotic Systems ◽  
Gaussian Approximation ◽  
Additive White Gaussian Noise ◽  
Design And Implementation ◽  
Shift Keying ◽  
Transmitted Signal ◽  
Chaos Shift Keying ◽  
Channel Environment

A new chaotic scheme named Flipped Chaotic On-Off Keying (FCOOK) is proposed for binary transmission. In FCOOK, the low correlation value between the stationary signal and its mirrored version is utilized. Transmitted signal for binary 1 is a chaotic segment added to its time flipped (mirrored) version within one bit duration, while in binary 0, no transmission takes place within the same bit duration. The proposed scheme is compared with the standard chaotic systems: Differential Chaos Shift Keying (DCSK) and Correlation Delay Shift Keying (CDSK). The Bit Error Rate (BER) of FCOOK is studied analytically based on Gaussian approximation method. Results show that the BER performance of FCOOK outperforms DCSK and CDSK in AWGN channel environment and with variousEb/Nolevels. Additionally, FCOOK offers a double bit rate compared with the standard DCSK.

scholarly journals Evaluasi Modulasi MFSK untuk Transmisi Data Melalui Kanal Suara GSM

Jurnal INKOM ◽  
2014 ◽  
Vol 8 (1) ◽  
pp. 37
Author(s):  
Rika Sustika ◽  
Oka Mahendra
Keyword(s):  
Mobile Communication ◽  
Bit Error Rate ◽  
Error Rate ◽  
Gaussian Noise ◽  
Linear Prediction ◽  
Signal To Noise Ratio ◽  
Additive White Gaussian Noise ◽  
Signal To Noise ◽  
Global System ◽  
Shift Keying

Pada tulisan ini, dievaluasi performansi skema modulasi MFSK (M-ary Frequency Shift Keying) untuk aplikasi pengiriman data melalui kanal suara GSM (Global System for Mobile Communication). Parameter yang dievaluasi berupa kesalahan bit trasmisi yang dinyatakan dengan laju kesalahan bit atau bit error rate (BER). Evaluasi ini dilakukan untuk menentukan besarnya orde M yang akan dipilih pada aplikasi pengiriman data digital melalui kanal suara GSM. Pada proses simulasi, data digital dikodekan menjadi simbol-simbol lalu dimodulasi menggunakan modulator MFSK menjadi data menyerupai pembicaraan (suara). Suara yang dihasilkan dikodekan dengan algoritma CELP (Code Excited Linear Prediction), kemudian dikirimkan melalui udara yang dimodelkan sebagai kanal AWGN (Additive White Gaussian Noise). Di sisi penerima, sinyal terima yang menyerupai suara ini didemodulasi dan dikonversi kembali menjadi data digital. Dari simulasi menggunakan Eb/No (signal to noise ratio) sebesar 6 dB, diperoleh laju bit 2,5 kbps dengan BER 2,01 x 10-3 untuk M=4, 2,22 x 10-3 untuk M=8, dan 1,87 x 10-3 untuk M=16.

An Effective Scheme of M-Ary Spread Spectrum System Based on Orthogonal Spread Spectrum and CPSK

2013 ◽  
Vol 765-767 ◽  
pp. 2696-2700
Author(s):  
Yue Xuan Liu ◽  
Shu Jian Liang ◽  
Yue Huai Ma ◽  
Song Xian Gong
Keyword(s):  
Monte Carlo Simulation ◽  
Bit Error Rate ◽  
Spread Spectrum ◽  
Bandwidth Efficiency ◽  
Transform Domain ◽  
Communication Scheme ◽  
System Synchronization ◽  
Orthogonal Spread ◽  
Simulation Results ◽  
Ber Performance

A hybrid M-ary spread spectrum (SS) communication scheme which combined with orthogonal SS and CPSK technique is proposed. Based on dual orthogonal SS, every SS code is treated as original code to adopt CPSK modulation, the unattached synchronous code is chosen to achieve system synchronization. At the receiver, A circular correlator based on transform domain processing is employed to de-spread the received signals. Compared with M-ary SS and CPSK, the proposed scheme is able to obtain higher bandwidth efficiency, stronger anti-intercept capability, and better synchronous performance. The Monte-Carlo simulation results demonstrate that the proposed scheme can achieve better synchronous and bit error rate (BER) performance under additional white gauss noise channel models.

scholarly journals Identification of Sonar Detection Signal Based on Fractional Fourier Transform

2018 ◽  
Vol 25 (s2) ◽  
pp. 125-131
Author(s):  
Wang Biao ◽  
Tang Jiansheng ◽  
Yu Fujian ◽  
Zhu Zhiyu
Keyword(s):  
Fourier Transform ◽  
Fractional Fourier Transform ◽  
Adaptive Threshold ◽  
Good Time ◽  
Transform Domain ◽  
Time Frequency ◽  
Watermark Embedding ◽  
Before And After ◽  
Different Characteristics ◽  
Fourier Transform Domain

Abstract Aiming at the source of underwater acoustic emission, in order to identify the enemy emission sonar source accurately. Using the digital watermarking technology and combining with the good time-frequency characteristics of fractional Fourier transform (FRFT), this paper proposes a sonar watermarking method based on fractional Fourier transform. The digital watermark embedding in the fractional Fourier transform domain and combined with the coefficient properties of the sonar signal in the fractional Fourier transform to select the appropriate watermark position. Using the different characteristics of the signals before and after embedding, an adaptive threshold was set for the watermark detection to realize the discrimination of sonar signals. The simulation results show the feasibility and has better resolution and large watermark capacity of this method, while the robustness of the watermark is better, and the detection precision is further improved.

scholarly journals Iterative based image and video denoising by fractional block matching and transform domain filtering

2021 ◽  
Author(s):  
Amir Mehdizadeh Hemat Abadi ◽  
Mohammad Reza Hosseiny Fatemi
Keyword(s):  
Image Denoising ◽  
Gaussian Noise ◽  
Additive White Gaussian Noise ◽  
Weighted Average ◽  
Block Matching ◽  
Objective Measures ◽  
Transform Domain ◽  
Video Denoising ◽  
Simulation Results ◽  
Fractional Motion Estimation

This paper presents an iterative algorithm for image and video denoising which is based on fractional block-matching and transform domain filtering. We propose fractional motion estimation technique to find the most accurate similar blocks for each block of an image which improves sparsity enabling effective image denoising. By taking the advantage of blocks similarity and wavelet transform domain filtering along with weighted average function (WAF) in an iterative based manner, we achieve a higher level of sparsity and a better exploiting of blocks similarity redundancies of noisy images that increase the chance of preserving details and edges in the restored image. Since our algorithm is iterative, we can tradeoff between image denoising degree and computational complexity. In addition, we develop a video denoising algorithm based on the proposed image denoising algorithm. The simulation results of images and videos contaminated by additive white Gaussian noise demonstrate that our algorithm substantially achieves better denoising performance compared with previously published algorithms in terms of subjective and objective measures.

scholarly journals ANÁLISIS DEL DESEMPEÑO DE UN SISTEMA DE COMUNICACIONES CON MODULACIÓN 16/64 QAM BASADO EN HARDWARE RECONFIGURABLE

2014 ◽  
Vol 25 (1) ◽  
pp. 99-112
Author(s):  
Juan Camilo Zemanate Zuñiga ◽  
Julián Andrés Muñoz Hidalgo ◽  
Victor Manuel Quintero Flórez
Keyword(s):  
Bit Error Rate ◽  
Error Rate ◽  
Gaussian Noise ◽  
Additive White Gaussian Noise ◽  
Field Programmable Gate Arrays ◽  
System Generator ◽  
Gate Arrays ◽  
Field Programmable ◽  
El Sistema ◽  
Programmable Gate Arrays

En el presente artículo se analiza el desempeño de un sistema de comunicaciones banda base con Modulación de Amplitud en Cuadratura (QAM, Quadrature Amplitude Modulation), implementado sobre un Arreglo de Compuertas Programables de Campo (FPGA, Field Programmable Gate Arrays), a partir de la Tasa de Error de Bit (BER, Bit Error Rate) y del comportamiento del hardware reconfigurable.El sistema de comunicaciones banda base consideró un canal de Ruido Blanco Gaussiano Aditivo (AWGN, Additive White Gaussian Noise) y las modulaciones 16 QAM y 64 QAM. Se diseñó a través de la herramienta System Generator® de Xilinx®, se validó (a nivel de simulación) por medio de la comparación con un modelo en Simulink ® y se implementó sobre un FPGA Spartan 6 de Xilinx® mediante la descarga de un archivo de programación. Como resultados se obtuvieron las curvas de desempeño del sistema de comunicaciones banda base con modulación 16/64 QAM, las cuales fueron comparadas con las curvas de desempeño teóricas ofrecidas por la herramienta Bertool® de Matlab® para su correspondiente análisis. De este modo, se concluyó que dada la similitud de las curvas de desempeño obtenidas a partir de System Generator®, Simulink®, implementación y Bertool®, el sistema de comunicaciones banda base alcanzó resultados óptimos sobre hardware reconfigurable.

scholarly journals A New Efficient Technique Based on Majority Logic Decoding to Decode Linear Block Codes

2019 ◽  
Vol 8 (4) ◽  
pp. 10946-10952
Keyword(s):  
Bit Error Rate ◽  
Error Rate ◽  
Gaussian Noise ◽  
Additive White Gaussian Noise ◽  
Block Codes ◽  
White Gaussian Noise ◽  
Majority Logic ◽  
Linear Block Codes ◽  
One Step ◽  
Majority Logic Decoding

One-Step Majority logic decoding (OSMLD) codes preset a very powerful error correcting schemes due to the simplicity of their decoder. However, families of these codes are limited to a few numbers. In this paper, we present a new adaptation which generalizes the majority-logic decoding for non OSMLD codes. This technique uses MIM method to select codewords from the dual of the code with last digit equal to one and then estimates the best threshold from which we obtain the best performance in term of the bit error rate (BER). The comparison between performances of the proposed technique and other coder/decoder schemes on AWGN (Additive White Gaussian Noise) channel proves its capacity in correcting more errors.

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