A new frequency synthesizer for coherent communication in frequency hopping spread spectrum multiple access communication systems

1983 ◽  
Vol 66 (1) ◽  
pp. 62-69
Author(s):  
Hisayoshi Sugiyama ◽  
Yoshifumi Amemiya
Keyword(s):  
Spread Spectrum ◽  
Communication Systems ◽  
Multiple Access ◽  
Frequency Synthesizer ◽  
Frequency Hopping ◽  
Frequency Hopping Spread Spectrum ◽  
Coherent Communication

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 Serial search code acquisition of FHSS system

2019 ◽  
Vol 10 (3) ◽  
pp. 233-239
Author(s):  
Muhanned Al-Rawi ◽  
Muaayed Al-Rawi
Keyword(s):  
Spread Spectrum ◽  
Fading Channel ◽  
Communication Systems ◽  
Multipath Fading ◽  
Frequency Hopping ◽  
Serial Search ◽  
Code Acquisition ◽  
Frequency Hopping Spread Spectrum ◽  
Improved Performance ◽  
Interference Frequency

Frequency 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 in frequency 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. In this paper, the serial search code acquisition, which is the first step of synchronization, is studied for frequency hopping spread spectrum (HFSS) system over Rayleigh fading channel. Simulation results show the effect of fading channel on the code acquisition.

scholarly journals Noise immunity of digital information transmission in a radio communication system by DQPSK signals with frequency hopping spread spectrum in the partial-band jamming noise.

2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
A.A. Paramonov ◽  
◽  
Van Zung Hoang ◽  
Keyword(s):  
Spread Spectrum ◽  
Communication System ◽  
Communication Systems ◽  
Noise Immunity ◽  
Frequency Hopping ◽  
Digital Information ◽  
Radio Communication ◽  
Large Signal ◽  
Frequency Hopping Spread Spectrum ◽  
Radio Communication System

The article deals with an algorithm for noncoherent reception of signals with Differential Quadrature Phase Shift Keying (DQPSK) using their weight processing for radio communication systems (RCS) with Frequency-hopping spread spectrum (FHSS) under Partial-band jamming noise (concentrated in the interference spectrum). Numerical calculations of bit/symbol error probability in the reception of DQPSK signals with a symbol-by-symbol frequency hopping are presented, as well as the results of modelling the considered reception algorithm for a radio communication system with an intra-symbol frequency hopping to study the noise immunity of receiving a DPQSK signal in the considered mode. It is shown that for not too large signal-to-jamming ratios when only a part of the operating frequencies is clogged by this noise, the noncoherent reception algorithm with weight processing provides higher noise immunity than the symbol-by-symbol frequency-hopping algorithm.

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