Performance enhancement of optical code-division multiple-access systems using transposed modified Walsh code

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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Performance enhancement using the bipolar capacity of bipolar coded fiber Bragg gratings and balanced detection in the spectral encoded code-division-multiple-access systems

Optics Communications ◽

10.1016/j.optcom.2003.11.047 ◽

2004 ◽

Vol 230 (4-6) ◽

pp. 319-324 ◽

Cited By ~ 2

Author(s):

Sangjo Park ◽

Bong Kyu Kim ◽

Chang-Soo Park

Keyword(s):

Code Division Multiple Access ◽

Multiple Access ◽

Performance Enhancement ◽

Fiber Bragg Gratings ◽

Bragg Gratings ◽

Balanced Detection ◽

Code Division Multiple

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Performance enhancement of OCDMA system based on sequential algorithm (SeQ) Code

Indonesian Journal of Electrical Engineering and Computer Science ◽

10.11591/ijeecs.v13.i2.pp831-836 ◽

2019 ◽

Vol 13 (2) ◽

pp. 831

Author(s):

C. A. S. Fazlina ◽

C. B. M. Rashidi ◽

S. N. Azemi ◽

S. A. Aljunid ◽

S. Yaakob

Keyword(s):

Code Division Multiple Access ◽

Multiple Access ◽

Cross Correlation ◽

Performance Enhancement ◽

Sequential Algorithm ◽

Correlation Property ◽

Coding System ◽

New Class ◽

Code Algorithm ◽

Code Division Multiple

<span>This paper presents a new class of Sequential Algorithm (SeQ) code for Optical Code Division Multiple Access (OCDMA) system. The SeQ code has advantages of various cross – correlation property at any given number of users, and code weights. The result shown, at error floor BER = 10-09, the SeQ code capability to support 190 numbers of simultaneous users was higher than those achieved by FCC (W=4), DCS (W=4) and MFH (W=4). SeQ code excellently support 190 number of users due to due to the arrangement of code algorithm and flexibility cross-correlation (0 and 1) role. In addition, SeQ code capable to support up to 70 km for bit rate 155 Mbps in comparison 622 Mbps, 1 Gbps, and 2 Gbps be able to support 40km, 30km and 20km respectively. Hence, we can ascertain that PIIN and MAI are successfully eliminated for SAC-OCDMA coding system.</span>

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Development of a secured optical code-division multiple access system by implementing hybrid 2D-modified Walsh code

Optical Engineering ◽

10.1117/1.oe.59.10.106107 ◽

2020 ◽

Vol 59 (10) ◽

Author(s):

Madhumita Sarkar ◽

Shila Ghosh

Keyword(s):

Code Division Multiple Access ◽

Multiple Access ◽

Access System ◽

Walsh Code ◽

Code Division Multiple ◽

Multiple Access System

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ANALISIS KINERJA KOMBINASI SISTEM CODE DIVISION MULTIPLE ACCESS MULTIPLE INPUT MULTIPLE OUTPUT DENGAN KODE PENEBAR WALSH PADA KANAL RAYLEIGH FADING

Jurnal SPEKTRUM ◽

10.24843/spektrum.2018.v05.i02.p36 ◽

2018 ◽

Vol 5 (2) ◽

pp. 285

Author(s):

I Gd. Tri Dharma Prawira ◽

I.G.A.K. Diafari Djuni Hartawan ◽

N. Pramaita

Keyword(s):

Code Division Multiple Access ◽

Multiple Access ◽

Rayleigh Fading ◽

Mimo System ◽

Multiple Input Multiple Output ◽

Walsh Code ◽

Multiple Input ◽

Input Multiple Output ◽

Code Division Multiple ◽

Mimo Technology

The increasing human population are same to the need for telecommunications. Code Division Multiple Access (CDMA) is one of the most widely used telecommunications technologies. But with the increasing number of users, this technology is no longer able to meet the needs of users. With the required capacity requirements, the CDMA system and Multiple Input Multiple Output (MIMO) technology are merged.To find out the performance of a combined CDMA MIMO system, the system was tested by increasing the number of users and Signal to Noise Ratio (SNR) where the spreading code used was the Walsh code and the channel used was Rayleigh Fading modeling. The reference value used as material for consideration are the value of Bit Error Rate (BER).The method used in testing the CDMA MIMO system is the increase number of users, starting with a single user up to 16 users and SNR values from -15 dB to a maximum of 15 dB.Where all users will be combined with the CDMA technique then it will be sent using MIMO technology. The system will be tested using a simulation of the MatLab R2012a software.The results of the simulation show the performance of the CDMA MIMO system when using SNR that is increasing high, the BER will be lower or better used for communication. Whereas for simulations using a user that increases it results in a BER value that is almost the same because of the nature of the orthogonal Walsh code so that each user does not experience interference with other users.

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