scholarly journals Impact of using CSS PHY and RTS/CTS Combined with Frame Concatenation in the IEEE 802.15.4 Non-beacon Enabled Mode Performance

2020 ◽  
Author(s):  
Norberto Barroca ◽  
Luís M. Borges ◽  
Fernando José Velez ◽  
Periklis Chatzimisios
Keyword(s):  
Spread Spectrum ◽  
Ieee 802.15.4 ◽  
Direct Sequence Spread Spectrum ◽  
Bandwidth Efficiency ◽  
Direct Sequence ◽  
Maximum Throughput ◽  
Physical Layers ◽  
Delay Performance ◽  
Minimum Delay ◽  
Throughput And Delay

This paper studies the performance improvement for the nonbeacon-enabled mode of IEEE 802.15.4 originated by the inclusion of the Request-To-Send/Clear-To-Send (RTS/CTS) handshake mechanism combined with frame concatenation. Under IEEE 802.15.4 employing RTS/CTS, the backoff procedure is not repeated for each data frame sent but only for each RTS/CTS set. The throughput and delay performance are mathematically derived for both the Chirp Spread Spectrum and Direct Sequence Spread Spectrum Physical layers for the 2.4 GHz band. The results show that the utilization of RTS/CTS significantly enhances the performance of IEEE 802.15.4 in terms of maximum throughput, minimum delay and bandwidth efficiency.

Improving reliability and latency of Wireless Sensor Networks using Concurrent Transmissions

2019 ◽  
Vol 67 (1) ◽  
pp. 42-50 ◽  
Author(s):  
Antonio Escobar-Molero
Keyword(s):  
Spread Spectrum ◽  
Communication Systems ◽  
Ieee 802.15.4 ◽  
Direct Sequence Spread Spectrum ◽  
Comprehensive Analysis ◽  
Wireless Sensor ◽  
Direct Sequence ◽  
Source To Sink ◽  
Two Factors ◽  
Simple Phase

Abstract Concurrent Transmissions (CT) based flooding appears as a highly reliable and low latency mechanism to achieve source-to-sink communication of packets within a Wireless Sensor Network (WSN). CT are usually misunderstood, since they are mainly analyzed in the baseband domain. A comprehensive analysis, including the effects of the carrier, demonstrates that they cannot work in simple phase-modulated communication systems due to the beating effect. In contrast, non-coherent frequency receivers offer a very robust behavior. CT applicability in IEEE 802.15.4 is mainly because of two factors: transmissions are usually demodulated as non-coherent MSK (as opposed to coherent OQPSK) and the Direct Sequence Spread Spectrum (DSSS), that helps minimizing the error rate.

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 .

Enhanced performance direct sequence spread spectrum code acquisition

1995 ◽  
Vol 31 (16) ◽  
pp. 1323-1325
Author(s):  
A.J. Eynon ◽  
T.C. Tozer
Keyword(s):  
Spread Spectrum ◽  
Direct Sequence Spread Spectrum ◽  
Direct Sequence ◽  
Code Acquisition

scholarly journals Adaptive Detection of Direct-Sequence Spread-Spectrum Signals Based on Knowledge-Enhanced Compressive Measurements and Artificial Neural Networks

Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2538
Author(s):  
Shuang Zhang ◽  
Feng Liu ◽  
Yuang Huang ◽  
Xuedong Meng
Keyword(s):  
Neural Networks ◽  
Artificial Neural Networks ◽  
Spread Spectrum ◽  
High Efficiency ◽  
Detection System ◽  
Direct Sequence Spread Spectrum ◽  
Detection Performance ◽  
Detection Methods ◽  
Direct Sequence ◽  
Artificial Neural

The direct-sequence spread-spectrum (DSSS) technique has been widely used in wireless secure communications. In this technique, the baseband signal is spread over a wider bandwidth using pseudo-random sequences to avoid interference or interception. In this paper, the authors propose methods to adaptively detect the DSSS signals based on knowledge-enhanced compressive measurements and artificial neural networks. Compared with the conventional non-compressive detection system, the compressive detection framework can achieve a reasonable balance between detection performance and sampling hardware cost. In contrast to the existing compressive sampling techniques, the proposed methods are shown to enable adaptive measurement kernel design with high efficiency. Through the theoretical analysis and the simulation results, the proposed adaptive compressive detection methods are also demonstrated to provide significantly enhanced detection performance efficiently, compared to their counterpart with the conventional random measurement kernels.

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