scholarly journals Fine time uplink synchronization for frequency-hopped spread spectrum satellite communication systems.

1989 ◽  
Author(s):  
Rolands Ezers
Keyword(s):  
Spread Spectrum ◽  
Communication Systems ◽  
Satellite Communication ◽  
Fine Time

Interplex for Constant Envelope in LEO Satellite Communication System

2013 ◽  
Vol 791-793 ◽  
pp. 2081-2087
Author(s):  
Yi Jun Chen ◽  
Kang Wu ◽  
Quan Jiang Jiang ◽  
Hui Jie Liu ◽  
Xu Wen Liang
Keyword(s):  
Spread Spectrum ◽  
Communication Systems ◽  
Satellite Communication ◽  
Spread Spectrum Communication ◽  
Constant Envelope ◽  
Signal Distortions ◽  
Limited Spectrum ◽  
Relationship Of ◽  
The Relationship ◽  
Leo Satellite

In modern LEO satellite communication systems, numerous singnals have to be located in a same frequency band because of limited spectrum resources. Thus, a bandwidth-efficient modulation, which has constant envelope characteristics and can alleviate signal distortions when using saturated power amplifiers is necessary to combine several signals to share the frequency resource. This paper presents the analytic interplex modulation expression in LEO satellite spread spectrum communication systems, and obtains the relationship of modulation efficiency, error rate and power ratio. Lastly, the appropriate choice of power radio is obtained in the case of three signals or four signals multiplexing. The work of this paper is an important guideline for constant envelope combined methodologies in LEO satellite spread spectrum communication systems.

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 .

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