scholarly journals Optimizations for FPGA-Based Ultrasound Multiple-Access Spread Spectrum Ranging

2020 ◽  
Vol 2020 ◽  
pp. 1-26
Author(s):  
Laurent Segers ◽  
An Braeken ◽  
Abdellah Touhafi
Keyword(s):  
Spread Spectrum ◽  
Multiple Access ◽  
Indoor Localization ◽  
Comparative Investigation ◽  
Direct Sequence Spread Spectrum ◽  
Frequency Hopping Spread Spectrum ◽  
Modulation Techniques ◽  
Access Mode ◽  
Ultrasound Signal ◽  
Ultrasound Signals

Indoor localization based on ultrasound signals has been carried out by several research groups. Most of the techniques rely on a single ultrasound pulse ranging, where the Time of Flight between the ultrasound emitters and a receiver is computed. Ultrasound orthogonal modulation techniques have also been investigated and allow to compute the range between the receiver and multiple simultaneous emitters with increased accuracy. However, no comparative investigation on the possibilities of each of the modulation techniques, comprising Direct Sequence Spread Spectrum, Frequency Hopping Spread Spectrum, and Chirp Spread Spectrum, could be found. Also, common optimized demodulation and correlation techniques for FPGA ready implementations are not widely available. Moreover, the hardware requirements for capturing modulated ultrasound signals could not be found for all the techniques. In this work, the different modulation techniques are optimized and implemented on an FPGA. A dedicated custom ultrasound MEMS-based receiver hardware for broadband ultrasound signal capturing is developed. Several modulation parameters are developed and applied for optimized signal processing. The FPGA resource consumptions are evaluated for the implemented methods. All methods are compared against the regular pulse ranging method, in both single-access and multiple-access ranging mode. Results show that, on average, up to 8 ultrasound-modulated emitters with an orthogonal sequence of length 63 can be demodulated on a Zynq7020 FPGA. In most cases, ranging up to 8 m is demonstrated in both single- and multiple-access mode, with accuracies generally remaining at a centimeter level. The requirements and capabilities for each of the modulation schemes are highlighted in the conclusions.

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 .

CDMA Modulation for Communication System Environment using Frequency Hopping Spread Spectrum

2020 ◽  
Vol 6 (1) ◽  
pp. EC-1-EC-13
Author(s):  
Imeldawaty Gultom ◽  
Keyword(s):  
Spread Spectrum ◽  
Communication System ◽  
Code Division Multiple Access ◽  
Multiple Access ◽  
Channel Model ◽  
Frequency Hopping ◽  
Direct Sequence Spread Spectrum ◽  
Direct Sequence ◽  
Frequency Hopping Spread Spectrum ◽  
Code Division Multiple

In this paper, an overall framework for a joint Special emphasis is placed on the communication segment of the sensing system at 85 GHz. Code division multiplexing using frequency hopping spread spectrum signals is implemented at 85 ghz to take advantage of reduced interference between ambient communication. The framework, which spans the entire chain of signal processing, mat lab is enabled, explained, and simulated using data networking. A template, able to scatter, fraud detection, including radio frequency-block and synchronization non-idealities are built up and analyzed. Also, the implementation of a channel model is into the Win Prop technology and embedded into the simulation of simu link. In the previous paper, they implemented the code division multiple access using a direct sequence spread spectrum at 77ghz for secure communication. Because of using 77ghz for the direct sequence spread spectrum, there will occur noise distortion and interference in the communication system. So that there will be poor system communication between transmitter and receiver. To overcome these problems, our paper explains the implementation of code division multiple access using frequency hopping spread spectrum for better and secure communications. By using this frequency-hopping spread spectrum technology, we can reduce the noise distortion and interference between the transmitter and the receiver. So that our system will be in proper condition to transmit the signals in the same range of frequency without any interference and distortion. FHSS systems can allow a higher aggregate bandwidth for coverage because FHSS provides more channels in the same range of frequencies. In accordance with the bit-error-rate, the module is assessed. By creating white Gaussian additive noise. The attribute is proven to reconcile the theoretical assumptions with the outcomes. By organizing a Rake-Receiver, the system is further boosted with structure configuration without any distortions.

Research on Key Technologies in Multi-Robotic Spread Spectrum Communication System

2013 ◽  
Vol 756-759 ◽  
pp. 2401-2405 ◽  
Author(s):  
Yun Hang Zhu ◽  
Qiong Cai ◽  
Xiu Liang Huang
Keyword(s):  
Spread Spectrum ◽  
Communication System ◽  
Code Division Multiple Access ◽  
Multiple Access ◽  
Rapid Development ◽  
Direct Sequence Spread Spectrum ◽  
Robotic System ◽  
Direct Sequence ◽  
Walsh Code ◽  
Code Division Multiple

It has become a hot research topic that to improve the coordination performance of multi-robotic system by communication. With rapid development of wireless communication and robot technologies, multi-robotic system based on spread-spectrum technology has become product of combining two technologies. Code Division Multiple Access (CDMA) technology is applied in multi-robotic communication system here. According to the modified m-Walsh sequence got by the way of analyzing the relation characteristic of Walsh-code and m-sequence, the best direct sequence spread spectrum (DSSS) PN code and the improved RAKE receiver scheme are proposed, which satisfied the requirements of real-time performance, reliability and confidentiality in multi-robotic communication system, and have great significance for the research of multi-robotic communication system.

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