排序方式: 共有19条查询结果,搜索用时 109 毫秒
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Anuar Mat Safar Syed Alwee Aljunid Amir Razif Arief Junita Nordin Naufal Saad 《Optical Review》2012,19(1):20-24
The use of minimal multiple access interference (MAI) in code design is investigated. Applying a projection and mapping techniques,
a code that has a zero cross correlation (ZCC) between users in optical code division multiple access (OCDMA) is presented
in this paper. The system is based on an incoherent light source—LED, spectral amplitude coding (SAC), and direct detection
techniques at the receiver. Using power spectral density (PSD) function and Gaussian approximation, we obtain the signal-to-noise
ratio (SNR) and the bit-error rate (BER) to measure the code performance. Making a comparison with other existing codes, e.g.,
Hadamard, MFH and MDW codes, we show that our code performs better at BER 10−9 in terms of number of simultaneous users. We also demonstrate the comparison between the theoretical and simulation analyses,
where the results are close to one another. 相似文献
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Thanaa Hussein Abd S. A. Aljunid Hilal Adnan Fadhil R. B. Ahmad 《Fiber and Integrated Optics》2013,32(6):397-416
Abstract This article presents a new code—the dynamic cyclic shift code—for spectral amplitude coding–optical code division multiple access systems. One of the important properties of the dynamic cyclic shift code is that the number of users can be increased without increasing the weight value. System performance was evaluated by using both theoretical analysis as well as the simulation experiment. The analysis results show that the proposed dynamic cyclic shift code can support more users in spectral amplitude coding–optical code division multiple access systems compared to spectral amplitude coding–optical code division multiple access codes. It was ascertained by performance evaluation that the dynamic cyclic shift code possesses ideal properties for use in spectral amplitude coding–optical code division multiple access systems. 相似文献
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Alayedi Mohanad Cherifi Abdelhamid Hamida Abdelhak Ferhat Bouazza Boubakar Seddik Aljunid Syed Alwee 《Wireless Personal Communications》2021,118(4):2675-2698
Wireless Personal Communications - In this paper, a novel code named three dimensional single weight zero cross correlation (3D-SWZCC) code has been developed for spectral/time/spatial (S/T/S)... 相似文献
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S.B. Ahmad Anas M.K. Abdullah M. Mokhtar S.A. Aljunid S.D. Walker 《Optical Fiber Technology》2009,15(1):26-32
We have implemented a new service differentiation technique in the optical domain using a spectral-amplitude-coding (SAC) variant of optical code division multiple access (OCDMA). The newly developed code, named KS (Khazani–Syed) is compared mathematically with other codes which use similar techniques. In our proposal, multiple weights are used to support ‘triple-play’ services (audio, video and data) with different quality-of-service (QoS) requirements. The results characterizing the bit-error-rate (BER) with respect to the total number of active users show that KS offers a significantly improved performance over the previous reported techniques by accommodating additional 30 users with shorter code length and smaller code weight at BER of 10?9. In variable weight system, we have shown that KS codes with larger weight always have the best performance when other users of different weights are present in the system. 相似文献
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A zero cross-correlation (ZCC) code is proposed to reduce the impact of system impairment and multiple access interference (MAI) in spectral amplitude coding optical code division multiple access (SAC-OCDMA) system. Bit-error-rate (BER) performance is derived taking into account the effect of some noises. The key to an effective OCDMA system is the choice of efficient address codes with good or almost zero correlation properties for encoding the source. The use of ZCC code can eradicate phase induced intensity noise (PIIN) which will contribute to better BER. Thus, we demonstrate, theoretically, the performance of optical ZCC code. It is shown that optical ZCC code can accommodate more users simultaneously for the typical error rate of optical communication system of 10−9. The result indicates that the established system not only preserves the capability of suppressing MAI, but also improves bit-error-rate performance as compared to the conventional coders. 相似文献
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Performance of OCDMA systems with new spectral direct detection (SDD) technique using enhanced double weight (EDW) code 总被引:1,自引:0,他引:1
This paper investigates the performance of enhanced double weight (EDW) code for spectral-amplitude-coding OCDMA (SAC-OCDMA) system using a newly proposed spectral direct detection (SDD) technique. EDW is the enhanced version of double weight (DW) code that possesses ideal cross-correlation properties and weight which can be any odd number greater than one. The theoretical and simulation results show that the proposed new spectral direct detection technique improves the performance compared to the conventional complementary subtraction technique. 相似文献