New Binary Code Combined with New Chaotic Map and Gold Code to Ameliorate the Quality of the Transmission

Author(s):  
Mohamed Krim ◽  
Adda Ali-Pacha ◽  
Naima Hadj-Said

<p>While the private radio communications field has grown in recent years, the communication method known as spread spectrum name has gained much prominence. A spread spectrum method can be combined with multiple access method CDMA for dividing sequences to create multi-user communication systems with very good performance of interference between symbols.The production of the chaotic sequence in scanning system and the information system according to DS-CDMA remains a hot research problem in this study to supervise in the knowledge wireless communication. This fact is still a question in establishing the secret code random spread sequence between the transmitter and the receiver.In DS-SS’s spreading is important to embed security information.It can avoid many problems in the complex calculation of the true circle. Furthermore the pseudo chaotic is reconstructed in the conventional gold to change shape with the logical operator “XOR” the results in simulation result shows in progress.It improves also the computing speed as this can solve the new equation of the problem in the original logistic map.There certainly has a kind in design: spreading chaotic sequence, chaos with gold code; including the number of users.So these are less in number and also limit the security and to can improve the ameliorate the quality of the transmissionand performance in terms of allowable number of users.The Bit error rate (BER) performance of the system is evaluated in multi-user environment under AWGN and reveals that the DS-SS system using new binary code combined with new logistic mapand gold code to ameliorate the quality of the transmission.</p>

2004 ◽  
Vol 14 (10) ◽  
pp. 3633-3646 ◽  
Author(s):  
WAI M. TAM ◽  
FRANCIS C. M. LAU ◽  
CHI K. TSE

In this Letter, we apply combined linear detector/parallel interference cancellation (PIC) detectors to jointly decode symbols in a multiple access chaotic-sequence spread-spectrum communication system. In particular, three different types of linear detectors, namely single-user detector, decorrelating detector and minimum mean-square-error detector, are used to estimate the transmitted symbols at the first stage of the PIC detector. The technique for deriving the approximate bit error rate (BER) is described and computer simulations are performed to verify the analytical BERs.


2004 ◽  
Vol 14 (01) ◽  
pp. 183-206 ◽  
Author(s):  
WAI MAN TAM ◽  
FRANCIS C. M. LAU ◽  
CHI K. TSE

In a multiple access spread-spectrum communication system, the bit error performance is usually limited by the mutual interference between users. The use of multi-user detection is an effective method to reduce such interference. In this paper, we consider two linear multi-user detectors, namely, decorrelating detector and minimum mean-square-error detector, applied to a multiple access chaotic-sequence spread-spectrum communication system. An approach to calculate the bit error rate (BER) for such systems is presented. The calculated BERs are compared with those obtained using brute-force computer simulations which give the true system performance.


Author(s):  
A. Shyshatskyi ◽  
O. Cherniak ◽  
A. Lyashenko ◽  
S. Paniuk ◽  
A. Doroshets ◽  
...  

Modern military radio systems operate in the complex conditions of the electronic environment, due to the limited frequency range, the influence of deliberate interference and signal fading. One of the ways to improve the effectiveness of military radio communication systems is to develop indicators (methods, techniques) for evaluating the effectiveness of military radio communication systems. The analysis found that known approaches to evaluating the performance of military radio communications systems are based on the use of bit error probability in a channel, which is a rather rough indicator of channel estimation. This necessitates the development of theoretical provisions for the transmission of discrete messages to military radio systems. In order to improve the known theoretical provisions for the transmission of discrete messages of military radio communication systems, the authors of the article developed indicators for assessing the quality of functioning of military radio communication systems that operate in complex conditions of electronic conditions. In the course of the study, the authors of the research substantiated two indicators of link quality in the fading channel: the probability of correctly receiving a message of finite duration and the likelihood of a link of finite duration without breaks. The first metric is the overall metric (communication) quality of the communication, and the second metric is the quality of the channel in the session of the final duration. During the research, the authors used the basic principles of communication theory, theories of insecurity, the theory of transmission of discrete messages, etc. The proposed results can be used to evaluate the status of radio channels when they are exposed to a variety of origins and signal fading. The practical significance of these results is that they can be used to upgrade existing radios or to develop new ones by developing appropriate software


Author(s):  
Fawzan Galib Abdul Karim Bawahab ◽  
Elvan Yuniarti ◽  
Edi Kurniawan

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 .


Author(s):  
Maksim Zhmakin ◽  
Irina Chadyuk ◽  
Aleksey Nadymov

A variant of implementation of a communication system with direct spread spectrum is presented in this article, simulation results are also presented, the main parameters of the system are taken, and conclusions are drawn.


2019 ◽  
Vol 7 (1) ◽  
pp. 62-72
Author(s):  
Shatha Abbas Hassan ◽  
Noor Ali Aljorani

The increasing importance of the information revolution and terms such as ‘speed’, ‘disorientation’, and ‘changing the concept of distance’, has provided us with tools that had not been previously available. Technological developments are moving toward Fluidity, which was previously unknown and cannot be understood through modern tools. With acceleration of the rhythm in the age we live in and the clarity of the role of information technology in our lives, as also the ease of access to information, has helped us to overcome many difficulties. Technology in all its forms has had a clear impact on all areas of daily life, and it has a clear impact on human thought in general, and the architectural space in particular, where the architecture moves from narrow spaces and is limited to new spaces known as the ‘breadth’, and forms of unlimited and stability to spaces characterized with fluidity. The research problem (the lack of clarity of knowledge about the impact of vast information flow associated with the technology of the age in the occurrence of liquidity in contemporary architectural space) is presented here. The research aims at defining fluidity and clarifying the effect of information technology on the changing characteristics of architectural space from solidity to fluidity. The research follows the analytical approach in tracking the concept of fluidity in physics and sociology to define this concept and then to explain the effect of Information Technology (IT) to achieve the fluidity of contemporary architectural space, leading to an analysis of the Skidmore, Owings and Merrill (SOM) architectural model. The research concludes that information technology achieves fluidity through various tools (communication systems, computers, automation, and artificial intelligence). It has changed the characteristics of contemporary architectural space and made it behave like an organism, through using smart material.


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