Performance of ZCZ codes in QS-DS-CDMA communication systems

Addad, Mouad; Djebbari, Ali; Dayoub, Iyad

doi:10.1016/j.sigpro.2019.06.008

Cited by 14 publications

(5 citation statements)

References 15 publications

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“…A new construction of a ZCZ sequence set is proposed, where all sequences are balanced. This is because ZCZ sequences were originally proposed for code division multiple access systems, where the balance property was not taken into con-sideration [11], [12]. Consequently, most of the ZCZ sequence sets proposed in the literature either have a limited number of balanced sequences or do not have any balanced sequences at all.…”

Section: The Contributions Of This Paper Are As Followsmentioning

confidence: 99%

Exact Analysis of MIMO Channel Estimation Based on Superimposed Training

Addad,

Toaba,

Djebbari

2024

JTIT

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In this paper, channel estimation capabilities of a multiple-input multiple-output (MIMO) system using superimposed training sequences are investigated. A new expression for estimation-error variance is derived. It is shown that the training sequences must be balanced and must have specific correlation properties. The latter are required only in a specific zone. Sequences that satisfy these criteria exist and are referred to as zero-correlation zone (ZCZ) solutions. Consequently, by using balanced ZCZ sequences, harmful direct current (DC) offset can be removed. Owing to their zero-cross correlation, interference from other transmitting antennas may be eliminated. Furthermore, a closed-form expression of the estimation-error variance can be obtained due to their impulse-like autocorrelation. To increase the number of antennas in the MIMO system, a new construction of ZCZ sequence set is proposed, in which all sequences are balanced

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Section: The Contributions Of This Paper Are As Followsmentioning

confidence: 99%

Exact Analysis of MIMO Channel Estimation Based on Superimposed Training

Addad,

Toaba,

Djebbari

2024

JTIT

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“…The encoder impresses a sequence code on the binary data. The sequence code is attributed to each user in order to withdraw the data at the receiver level: the received signal will be contrasted with the sequence code to recover the data [7], [8].…”

Section: Ds-ocdmamentioning

confidence: 99%

Performance improvements of a VLC system, in a V2X context, using a different multiplexing technique

2023

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This paper scrutinizes visible light communication (VLC) employing hybrid optical time division multiplexing (OTDM) wavelength division multiplexing (WDM). It also demonstrates the simulation of VLC using the direct sequence optical code division multiple access (DS-OCDMA) system developed by OptiSystem-Matlab Co-simulation. The profits of WDM and OTDM capacities have been combined using two levels of freedom to build up of the system. The performances are demonstrated in the simulated findings of the bit error rate (BER) in relationship with the data rate and the number of users. First, the simulated results display the usefulness of the system. Then, the number of users has been significantly enhanced. Besides, the OCDMA functions by appointing a specific code to each user and could provide asynchronous and simultaneous access to numerous users. One drawback is multiple access interference (MAI). The use of very long code sequences is crucial in order to lessen this effect. Hence, very large bandwidths are essential. This study aims at demonstrating, through system simulation, the practicability of an all-optical conventional correlation receiver dedicated to a DS-OCDMA access network link. Again, OptiSystem has been used to realize our blocks.

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“…CDMA has diverse codes for each user and offers complete bandwidth to each code in the code matrix. Furthermore, CDMA can be functional in diverse domains such as optical CDMA (OCDMA) systems, 15 military satellite communication systems, 16 optical Network on Chip systems, 17 multiple input multiple output radar 18 and cellular underwater OCDMA network 19 …”

Section: Introductionmentioning

confidence: 99%

Performance enhancement of visible light communication (VLC) system incorporating WMZCC‐OCDMA codes and PDM‐QPSK‐DSP data encoding

Kaur

Grewal²

2022

Int J Communication

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Multi-user optical code division multiplexing (OCDMA) in visible light communication (VLC) is an imminent domain for providing an even distribution of available bandwidth and improved security. Q4R1Zero cross-correlation (ZCC) codes are widely reported, and improved performance is offered by them due to insignificant multiple access interference (MAI). However, practically, MAI exists in ZCC codes due to adjacent weights (W) in the code matrix rows for each user. Therefore, a novel ZCC code with a nonadjacent W is designed in this work to eradicate MAI limitations and is named weight managed ZCC codes (WMZCC). An indoor 100 Gbps/User OCDMA-VLC system is realised using polarisation division multiplexed quadrature phase shift keying (PDM-QPSK) and digital signal processing (DSP). Incorporation of DSP in the coherent receiver compensates the effects of dispersion and nonlinear effects and also performs phase estimation. Further, a state-of-the-art comparison of WMZCC codes with diagonal identity matrix (DIM) and zero cross-correlation resultant weight (ZCCRW) codes has been performed in terms of log symbol error rate (SER), Q factor, error vector magnitude percentage (EVM%) and log bit error rate (BER) log at different VLC lengths, Q4R1Transmitter half angles (THA), incidence half angles (IHA) and optical concentrators (cm 2 ). Constellations are analysed with and without DSP, and according to the author's best knowledge, a 100 Gbps VLC system for five users covering 6 m at À3.42 log BER is demonstrated for the first time. Results revealed that weight management in WMZCC codes makes its performance improve as compared with ZCCRW and DIM codes.

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Performance of ZCZ codes in QS-DS-CDMA communication systems

Cited by 14 publications

References 15 publications

Exact Analysis of MIMO Channel Estimation Based on Superimposed Training

Exact Analysis of MIMO Channel Estimation Based on Superimposed Training

Performance improvements of a VLC system, in a V2X context, using a different multiplexing technique

Performance enhancement of visible light communication (VLC) system incorporating WMZCC‐OCDMA codes and PDM‐QPSK‐DSP data encoding

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