A new model to enhance the QoS of spectral amplitude coding-optical code division multiple access system with OFDM technique

Aldhaibani, A. O.; Rahman, Tharek Abd; Aljunid, S. A.; Hindia, Mohammad Nour; Hanafi, Effariza

doi:10.1007/s11082-016-0750-4

Cited by 18 publications

(5 citation statements)

References 10 publications

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“…The signal from the desired user reaching PD after modulating with OFDM can be expressed as [1] where B op n and C are the optical bandwidth, the number of subcarriers having a range from 1 to z, i.e., the total number of subcarriers and complex data at z subcarriers, respectively. The OFDM signal is produced by using MATLAB.…”

Section: Performance Analysismentioning

confidence: 99%

“…Orthogonal multicarrier modulation (OMCM), also known as orthogonal frequency division multiplexing (OFDM), is a data transmission technology that works well in fading and multipath networks [1]. It is also a digital multi-carrier modulation technology that can be utilized in high-data rate applications on many telecommunication protocols, including wireless communications and multimedia [2].…”

Section: Introductionmentioning

confidence: 99%

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Design of a High-Speed OFDM-SAC-OCDMA-Based FSO System Using EDW Codes for Supporting 5G Data Services and Smart City Applications

Singh

Kříž²,

Kamruzzaman³

et al. 2022

Front. Phys.

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A novel free space optics (FSO) system is introduced in this article by combining orthogonal frequency division multiplexing (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 × 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.

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Section: Performance Analysismentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Design of a High-Speed OFDM-SAC-OCDMA-Based FSO System Using EDW Codes for Supporting 5G Data Services and Smart City Applications

Singh

Kříž²,

Kamruzzaman³

et al. 2022

Front. Phys.

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“…1 shows the receiver operational block diagram for optical PPM-CDMA using SAC scheme (inset), based on SIC. Due to the flat Power Spectral Density (PSD) of the source in Optical CDMA system using SAC detection, the PIIN, shot noise and thermal noise introduced significant degradation in the system performance [17], [19].…”

Section: Ii3 Performance Analysis Of Optical Cdma Systemsmentioning

confidence: 99%

Performance Enhancement of Optical PPM-CDMA Using Successive Interference Cancellation Scheme

Alsowaidi

Eltaif

Mokhtar

2018

IRECAP

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A comprehensive mathematical model of Successive Interference Cancellation (SIC) using Direct Sequence (DS) and Spectral Amplitude Coding (SAC), which is employed in incoherent optical CDMA using On-Off Keying (OOK) Pulse Position Modulation (PPM) and On-Off Keying (OOK) considering the presence of Phase-Induced Intensity Noise (PIIN), shot noise and thermal noise is presented in this work. SIC scheme has the potential to suppress Multiple Access Interference (MAI). The concept of SIC is the following: detection is taken place in successive stages where the most reliable symbols are chosen at each stage. Where the interference contributed by the already detected symbols will be removed. It has been found out that, theoretically, the size of M-ary on optical CDMA system limits the MAI effect. Thus, the system performance improves with the increasing of M-ary PPM. Hence, the system using PPM has better performances if compared to the one using OOK, due to a lower average number of interfering optical pulses. In addition, a lot of users can be accommodated with SIC/SAC-optical CDMA based PPM signaling system instead of the SIC/SAC-optical CDMA based OOK one.

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“…OFDM is a digital technology for data transmission and multicarrier modulation that operates in wireless communications and multipath networks [33,34]. It employs inverse fast Fourier transform (IFFT), which requires parallel data streams to be transmitted over sub-carriers that are orthogonal and have the same frequency range.…”

Section: Introductionmentioning

confidence: 99%

Enhancing security and capacity in FSO transmission for next-generation networks using OFDM/OCDMA-based ICSM codes

Abd El-Mottaleb,

Singh,

Alshathri

et al. 2023

Front. Phys.

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In order to address the growing demands for both enhanced security levels and increased transmission capacity, this research proposes a novel approach for free space optical (FSO) transmission. The proposed design incorporates an identity column shift matrix (ICSM) code to ensure robust security. Additionally, capacity enhancement is achieved through the utilization of a 4-level quadrature amplitude modulation (4-QAM) scheme in conjunction with an orthogonal frequency division multiplexing (OFDM) modulator. The performance of the system is evaluated across three channels, each transmitting data at a rate of 20 Gb/s, while operating in an FSO channel that is subjected to varying atmospheric attenuation effects and atmospheric turbulence. Real meteorological data from three different cities [Alexandria, Egypt; Jeddah, Kingdom of Saudi Arabia (KSA); and Hyderabad, India], situated across two continents, are incorporated to demonstrate the practicality of implementing the proposed model in real-world environments. The experimental results reveal that an increase in atmospheric turbulence leads to a higher bit error rate (BER) and lower received optical power (ROP), resulting in degraded data reception. Furthermore, the study examines the impact of weather conditions, indicating that the longest and shortest propagation ranges of 12.5 and 0.286 km, respectively, are achieved under clear weather and heavy dust storms. These conditions yield an ROP of −9.5 dBm and a log (BER) of approximately −2.5. Conversely, in the presence of strong turbulence, the performance further deteriorates. The proposed model demonstrates its ability to transmit a message signal over a distance of 0.8375 km, with a log (BER) of −2.6 under weak atmospheric turbulence. However, under strong atmospheric turbulence at the same distance, the log (BER) increases to −0.5. Regarding specific cities, the FSO range for transmitting information signals is found to be 9.58 km in Jeddah, which decreases to 6.58 km in Alexandria and 5.17 km in Hyderabad due to the increased atmospheric attenuation in these cities.

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A new model to enhance the QoS of spectral amplitude coding-optical code division multiple access system with OFDM technique

Cited by 18 publications

References 10 publications

Design of a High-Speed OFDM-SAC-OCDMA-Based FSO System Using EDW Codes for Supporting 5G Data Services and Smart City Applications

Design of a High-Speed OFDM-SAC-OCDMA-Based FSO System Using EDW Codes for Supporting 5G Data Services and Smart City Applications

Performance Enhancement of Optical PPM-CDMA Using Successive Interference Cancellation Scheme

Enhancing security and capacity in FSO transmission for next-generation networks using OFDM/OCDMA-based ICSM codes

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