scholarly journals Synchronization in DSSS system

2020 ◽  
Vol 11 (2) ◽  
pp. 88-94
Author(s):  
Izz K. Abboud ◽  
Laith A. Kunbar ◽  
Abbas S. Hassan
Keyword(s):  
Spread Spectrum ◽  
Communication Systems ◽  
Multipath Fading ◽  
Direct Sequence Spread Spectrum ◽  
Direct Sequence ◽  
Code Tracking ◽  
Spreading Sequence ◽  
Transmitted Sequence ◽  
Low Probability ◽  
Improved Performance

AbstractDirect sequence spread spectrum (DSSS) communication systems offer huge performance focal points in perspective on their low probability of block, improved performance in multipath fading situations and their capacity to stay away from interference by spreading the signal over a wide bandwidth subsequently conveying the power. For the transmitted sequence to be effectively received and demodulated, the spreading sequence utilized at the receiver ought to be like that utilized in the transmitter. This paper uses MATLAB Simulink to show a technique for synchronizing the code clock at the receiver with the code clock at the transmitter. This fine arrangement procedure is known as code tracking.

scholarly journals Code Tracking of DSSS Signal over AWGN Channel

2019 ◽  
Vol 19 (1) ◽  
pp. 13-17
Author(s):  
Mohanad Abdulhamid ◽  
Hassan Omar
Keyword(s):  
Spread Spectrum ◽  
Communication Systems ◽  
Multipath Fading ◽  
Direct Sequence Spread Spectrum ◽  
Code Tracking ◽  
Spreading Sequence ◽  
Transmitted Sequence ◽  
Significant Performance ◽  
Alignment Process ◽  
Improved Performance

AbstractDirect sequence spread spectrum (DSSS) communication systems offer significant performance advantages in view of their low probability of intercept, improved performance in multipath fading environments and their ability to avoid interference by spreading the signal over a wide bandwidth hence distributing the power. For the transmitted sequence to be correctly received and demodulated, the spreading sequence used at the receiver should be similar to that employed in the transmitter. This paper utilizes MATLAB Simulink to demonstrate a method of synchronizing the code clock at the receiver with the code clock at the transmitter. This fine alignment process is knownas code tracking.

scholarly journals Design of Code Acquisition Method of FHSS System

2019 ◽  
Vol 19 (1) ◽  
pp. 1-5
Author(s):  
Mohanad Abdulhamid ◽  
Gabriel Ogwali
Keyword(s):  
Spread Spectrum ◽  
Communication Systems ◽  
Additive White Gaussian Noise ◽  
Multipath Fading ◽  
Code Acquisition ◽  
Frequency Hopping Spread Spectrum ◽  
Transmitted Sequence ◽  
Improved Performance ◽  
Interference Frequency ◽  
Acquisition Method

AbstractFrequency hopping spread spectrum (FHSS) communication systems offer significant performance advantages in view of their low probability of intercept, improved performance in multipath fading environments and their ability to avoid interference by hopping into low interference frequency channels. For the transmitted sequence to be correctly received and demodulated, the frequency hop sequence used at the receiver should be similar to that employed in the transmitter. Code acquisition infrequency hopping attempts to address this problem by providing a frequency hop pattern at the receiver that is nearly identical to that used at the transmitter. Code acquisition brings the alignment between the transmitter and the receiver hop pattern to at least one hop period. The main objective of this paper is to design and demonstrate a FHSS code acquisition method. The type of channel used is Additive White Gaussian Noise (AWGN).

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 .

scholarly journals Implementation of the asynchronous signals reception method with the direct sequence spread spectrum

2020 ◽  
Vol 30 (2) ◽  
pp. 49-54
Author(s):  
I. V. Egorov ◽  
D. V. Gaivoronskii
Keyword(s):  
Spread Spectrum ◽  
Communication Systems ◽  
Block Diagram ◽  
Random Sequence ◽  
Direct Sequence Spread Spectrum ◽  
Practical Implementation ◽  
Direct Sequence ◽  
Radio Communication ◽  
Radio Stations ◽  
Synchronization Mechanisms

The physical and logical organization of most existing communication systems provides for additional options (transmission of known preambles, the presence of an additional synchronization channel) that simplify synchronization. At the same time, in the practical implementation of radio communication systems, it is necessary to solve the problems of developing additional synchronization mechanisms that can reduce the time it takes to synchronize to reduce energy consumption and increase channel capacity. Thus, the existing problem of the asynchrony of the generators of physically remote radio stations is relevant. One of the possible solutions is asynchronous signal reception with the direct sequence spread spectrum. It allows converting the original binary signal into a pseudo-random sequence for modulating the carrier. The current article is devoted to the characterization of this method and has the following items presented: the transmitter and receiver block diagram, sufficient to explain the proposed method; methods for compensating for effects arising from the asynchrony of the transmitter and receiver generators. Since synchronization is generated according to the correlation peaks that correspond to the data bits, it is possible to set the frequency of the chips on the transmitter to jitter artificially and supplement the pseudo-random sequence with several random chips, which complicates the unauthorized detection of the transmitted signal.

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