A new free space optical (FSO) system is proposed by combining spectral amplitude coding optical code division multiple access (SAC-OCDMA) with polarization divisionmultiplexing (PDM). Enhanced double weight (EDW) co...
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A new free space optical (FSO) system is proposed by combining spectral amplitude coding optical code division multiple access (SAC-OCDMA) with polarization divisionmultiplexing (PDM). Enhanced double weight (EDW) codes are employed for the SAC-OCDMA system as well as single photodiode detection (SPD). Two polarization signals (x-polarization and y-polarization) are used;each carrying three different channels. Each channel carries 10 Gbps, so, the system capacity is increased to 60 Gbps. The proposed system is simulated and its performance is compared for the six channels under different weather conditions and is provided through the bit error rate (BER) metric. The obtained results assure a successful transmission under various climate with overall 60 Gbps capacity.
A novel free space optics (FSO) system is introduced in this article by combining orthogonal frequency divisionmultiplexing (OFDM) with spectral amplitude coding optical code division multiple access (SAC-OCDMA) to b...
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A novel free space optics (FSO) system is introduced in this article by combining orthogonal frequency divisionmultiplexing (OFDM) with spectral amplitude coding optical code division multiple access (SAC-OCDMA) to be implemented in 5G technology and smart cities. Enhanced double-weight (EDW) codes are used as signature codes, while for the detection technique, single photodiode detection (SPD) is applied for the SAC-OCDMA system. OFDM with a four-quadrature amplitude modulation (4-QAM) scheme is assigned to the three users in the SAC-OCDMA system, each carrying 15 Gbps. Adverse weather conditions, such as clear, fog, haze, rain, and dust storm, that affect the FSO channel are considered. The performance of the proposed system is evaluated in terms of log of bit error rate and received power at different propagation distances. The simulation results show successful transmission of 3 x 15 Gbps with a propagation range of 3.45 km under clear air and 1.316, 1.045, and 0.7 km under rain conditions (light, medium, and heavy rain) with a received power of -12.6 dBm. As for haze conditions, the range and received power are 2.391 km with -13 dBm for low haze, 1.591 km with -12.7 dBm for medium haze, and 1.025 km with -12.6 dBm for heavy haze. The range is reduced and becomes 1.085, 0.784, and 0.645 km under fog conditions (light, medium, and heavy fog) with -12.6 dBm received power. Furthermore, the system achieved a range of 0.681, 0.232, and 0.102 km under dust conditions (light, medium, and heavy dust) with a received power of -16 dBm.
The focus of this work is to consolidate a review of accomplished research in the field of opticalcodedivisionmultipleaccesses (OCDMA), to outline the state-of-the-art comparison, and to recognize the prominent tr...
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The focus of this work is to consolidate a review of accomplished research in the field of opticalcodedivisionmultipleaccesses (OCDMA), to outline the state-of-the-art comparison, and to recognize the prominent trends as well as limitations. codedivisionmultipleaccess (CDMA) has prospered as a vital solution for numerous applications such as cellular mobile communication-based wireless network technology and wired/wireless local area networks that include areas of unlicensed industry, medicine, and science. Due to the commercial utilization of the various advantages of CDMA, it has raised the matter of whether optical technology reliant communications provide the noteworthy advantages to optical networks as well as what are the technologies that facilitate optical chip-based (codedivision) networks. Aforementioned matter has been addressed in the context of the incorporation of OCDMA in the systems through several experiments of laboratory-based test-bed investigations, field trials, and simulation analysis of multiple users in the recent research works. The performance of OCDMA has an edge over wavelength divisionmultiplexing and offers an unmatched capacity that is seen through simulations. To cater the explosive expansions in internet application, different spectralamplitudecodes have been proposed till now. We present a review of the different spectralamplitudecodes based on the reported works in spectralamplitudecode OCDMA systems. For the purpose of state-of-the-art comparison, parameters considered are data speeds, advanced modulation formats, bit error rate, extinction ratio, decision algorithms, photonic efficiencies of photodetectors, frequency bands, signal-to-noise ratio, forward error correction, photodetector noises, etc., and simulations are carried out in similar input environments. We explore the advantages/limitations of the spectralamplitudecodes, recent progress in the technology, practical works on spectralamplitudecoding (SAC
We propose a family of one-dimensional subtracted square codes in the spectral amplitude coding optical code division multiple access system. The proposed codes perform the subtraction and multiplication operations to...
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We propose a family of one-dimensional subtracted square codes in the spectral amplitude coding optical code division multiple access system. The proposed codes perform the subtraction and multiplication operations to give one-to-one mappings function, which produces the code sequences of 1-D subtracted square codes. The proposed structure uses one optical line terminal to produce all of the transmitters. This proposed system overcomes the interference from other simultaneous users, known as multiuser interference, and the cross-correlations suppress the phase-induced intensity noise. In numerical simulations using the proposed 1-D subtracted square codes, we show that 83 simultaneous users can be supported at a bit error rate of . This number of simultaneous users in the proposed system using the 1-D subtracted square codes is superior to that in the other systems using the 1-D M sequence codes, 1-D RSQC codes, and 1-D ESP codes. The proposed system using the 1-D subtracted square codes achieves a data transmission rate of 3.2 Gbps.
A six-channel 2.4GHz subcarrier multiplexing opticalcodedivisionmultipleaccess (SCM-OCDMA) system in conjunction with the selective excitation of LP01 and LP02 modes is presented for a multimode fiber Local Area N...
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ISBN:
(纸本)9781467360739;9781467360753
A six-channel 2.4GHz subcarrier multiplexing opticalcodedivisionmultipleaccess (SCM-OCDMA) system in conjunction with the selective excitation of LP01 and LP02 modes is presented for a multimode fiber Local Area Network. Simulation results demonstrate that mode selectivity increases the bandwidth-distance product and improves the BER performance of the channel.
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