scholarly journals Simulasi Kinerja DSSS Menggunakan Kode Barker Pada Kanal Rayleigh Fading

2020 ◽  
Vol 17 (2) ◽  
pp. 42
Author(s):  
Raisah Hayati
Keyword(s):  
Spread Spectrum ◽  
Rayleigh Fading ◽  
Direct Sequence Spread Spectrum ◽  
Direct Sequence

Sistem komunikasi spread spectrum merupakan teknik pengiriman sinyal yang tahan terhadap gangguan dan mempunyai tingkat keamanan informasi yang cukup tinggi pada saat pengiriman. Salah satu teknik spread spectrum yang dikembangkan adalah Direct Sequence Spread Spectrum (DSSS). Pada sistem DSSS digunakan kode unik untuk menebarkan sinyal baseband yang akan dimodulasi digital bersama sinyal informasi. Pada penelitian ini akan diuji pengaruh panjang kode penebar Barker terhadap kinerja DSSS pada kanal Rayleigh Fading. Dari hasil pengujian, untuk level noise Rayleigh Fading yang sama diperoleh nilai BER = 1 untuk panjang kode Barker sama dengan 2, dan BER = 0,4 untuk panjang kode Barker 3, 4, 5, 7, 11, dan 13.

Research of Anti-Multipath Interference Capability in Direct Sequence Spread Spectrum Communication System by Simulation

2013 ◽  
Vol 846-847 ◽  
pp. 592-595
Author(s):  
Ping Hua Zhang ◽  
Xiu Liang Huang ◽  
Zhong Yue He
Keyword(s):  
Time Delay ◽  
Fading Channels ◽  
Spread Spectrum ◽  
Communication System ◽  
Rayleigh Fading ◽  
Multipath Fading ◽  
Direct Sequence Spread Spectrum ◽  
Rayleigh Fading Channels ◽  
Direct Sequence ◽  
Simulation Results

The effects of multipath fading with time delay longer or shorter than one chip interval on DSSS system are mathematically and experimentally researched. Simulation results indicate that DSSS system can efficiently overcome multipath fading in multipath Rayleigh Fading channels. And the spreading gain is not the higher the better, it must be chosen reasonably.

scholarly journals Coherent RAKE Receiver for CPM-Based Direct Sequence Spread Spectrum

2016 ◽  
Vol 2016 ◽  
pp. 1-7
Author(s):  
Ke Zhou ◽  
Shilian Wang ◽  
Eryang Zhang
Keyword(s):  
Spread Spectrum ◽  
Rayleigh Fading ◽  
Phase Synchronization ◽  
Rake Receiver ◽  
Continuous Phase ◽  
Direct Sequence Spread Spectrum ◽  
Multipath Channel ◽  
Continuous Phase Modulation ◽  
Data Detection ◽  
Direct Sequence

Direct sequence spread spectrum (DSSS) using continuous phase modulation (CPM) inherits the techniques’ benefits, constant envelope, anti-interference, and spectral efficiency. To get diversity gains over a Rayleigh-fading multipath channel as in conventional direct sequence spread-spectrum binary phase shift keying (DSSS-BPSK) system, a new class of coherent RAKE receivers is proposed in this work. By introducing chip branch metric to the receiver scheme, despreading and data detection can be done meanwhile based on Maximum Likelihood Sequence Detection (MLSD). Compared to the conventional RAKE receiver which sums decision metrics symbol-by-symbol, the proposed DSSS-CPM RAKE receiver accumulates symbol branch metric increments over every phase state of multiple paths after chip phase synchronization. Numerical results show that DSSS-CPM using the synchronous despreading and demodulation algorithm has no performance loss compared to CPM system that employs MLSD algorithm under the same test conditions. Moreover, the proposed RAKE receiver outperforms conventional RAKE receiver and achieves a remarkable diversity gain of bit error rate (BER) under the Rayleigh-fading multipath channel.

Analisis Karakterisasi Teknologi Direct Sequence Spread Spectrum Dan Frequency Hopping Spread Spectrum

2019 ◽  
Vol 2 (2) ◽  
pp. 129-138
Author(s):  
Fawzan Galib Abdul Karim Bawahab ◽  
Elvan Yuniarti ◽  
Edi Kurniawan
Keyword(s):  
Spread Spectrum ◽  
Communication Systems ◽  
Multiple Access ◽  
Frequency Hopping ◽  
Direct Sequence Spread Spectrum ◽  
Direct Sequence ◽  
Frequency Hopping Spread Spectrum ◽  
Two Systems ◽  
The Difference

Abstrak. Pada penelitian ini, telah dilakukan analisa karakterisasi pada teknologi Direct Sequence Spread Spectrum dan Frequency Hopping Spread Spectrum, sebagai salah satu teknik multiple-access pada sistem komunikasi. Karakterisasi dilakukan untuk mencari bagaimana cara meningkatkan keoptimalan kedua sistem tersebut, dalam mengatasi masalah interferensi dengan sistem dan channel yang sama. Dan juga untuk menentukan veriabel apa yang mempengaruhi keoptimalan kedua sistem tersebut. Karakterisasi dilakukan dengan menentukan variabel-variabel yang mempengaruhi keoptimalan keduanya. Hasil dari karakterisasi, diketahui variabel-variabel yang mempengaruhi kemampuan sistem DSSS yaitu nilai frekuensi spreading (). Sedangkan untuk sistem FHSS yaitu nilai frekuensi spreading ( dan ) dan selisih antara frekuensi hopping data dengan frekuensi hopping interferensi . Kata Kunci: BER, DSSS, FHSS, Interference, Spread spectrum. Abstract. In this study, characterization of Direct Sequence Spread Spectrum and Frequency Hopping Spread Spectrum technologies have been done, as one of the multiple-access techniques in communication systems. Characterization is done to find out how to improve the ability of the two systems, in solving interference problems with the same system and channel. And also to determine what veriabel affects the ability of the two systems. Characterization is done by determining the variables that affect the ability of both. The results of the characterization, known variables that affect the ability of the DSSS system are the spreading frequency value (). As for the FHSS system, the spreading frequency value ( and ) and the difference between frequency hopping data with frequency hopping interference .

Sign in / Sign up

Export Citation Format

Share Document