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 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).

scholarly journals Study of Code Acquisition of FHSS System Over Rician Channel

2019 ◽  
Vol 24 (1) ◽  
pp. 68-76
Author(s):  
Muhanned Al-Rawi
Keyword(s):  
Spread Spectrum ◽  
Fading Channel ◽  
Time Synchronization ◽  
Frequency Hopping ◽  
Rician Fading ◽  
Frequency Diversity ◽  
Code Acquisition ◽  
Frequency Hopping Spread Spectrum ◽  
Pseudo Noise ◽  
Frequency Sequence

Abstract Frequency hopping is used in different communications systems for its robustness by providing frequency diversity against jamming and interfering signals. Successful detection and demodulation of a frequency hopping signal is dependent on proper tuning to transmit frequency and time synchronization of the burst. The sequence of hop frequencies is generally determined by a Pseudo-Noise (PN) sequence and time synchronization is achieved using synchronization preambles in the transmit burst. Successful acquisition of the hop frequency sequence could be achieved when at least a single burst’s data is successfully decoded at the receiver. This paper studies the serial search code acquisition which is the first step of synchronization for frequency hopping spread spectrum (FHSS) system over Rician fading channel. Simulation results show the effect of fading channel on the code acquisition.

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 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.

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.

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