Tawfig Eltaif

A Novel Successive Interference Cancellation Scheme in OCDMA System

In DC/CDMA systems, overcoming near/far effects is imperative for satisfactory performance. One way to combat the near/far effect is to use stringent power control. Another approach is multiuser detection (MUD). In addition to mitigating the near/far effect, MUD has more fundamental potential of raising capacity by canceling MAI. In this paper we going to present MUD schemes known as successive interference cancellation (SIC). Where DS-OCDMA receiver was studied based on the SIC technique without hard limiter. Also we mention to use this technique with hardlimiter placed before the nondesired users.

Analytical comparison of optical code-division multiple-access systems with and without a successive interference cancellation scheme using modified prime-sequence codes

We analyzed direct-sequence code-division multiple-access system using a successive interference cancellation (SIC) scheme. Modified prime-sequence codes are utilized as signature sequences, and the performance measure studied in this paper takes into account the the effect of imperfect interference cancellation. The basic principle of the SIC scheme is to subtract the strongest received signals from the original signal one by one till all users have been detected and demodulated. In this analysis we have compared optical code-division multiple-access systems with and without the cancellation scheme, and it is shown that the SIC scheme with −20-dBm effective power can suppress multiple-access interference better than the system without cancellation.

Performance analysis of successive interference cancellation scheme for optical CDMA using modified prime sequence codes

In this paper, we propose a new technique in direct sequence code division multiple access system using on-off key and modified prime sequence code, the scheme of this technique dubbed successive interference cancellation (SIC). The basic principle of SIC scheme is to subtract the strongest received signals from the original signal one by one till all users have been detected, and demodulated. In this analysis we take in account the possibilities of errors in previous cancellation. It has been shown that the proposal IC scheme with (-20dBm) effective power can suppress multiple-access interference (MAI), and improve the system performance significantly.

Analysis of Successive Interference Cancellation Scheme using OOC code in Optical CDMA Systems

Multiuser detection is an effective method to suppress MAI. In this paper we propose one of the multiuser detection schemes which are called Successive interference cancellation (SIC), this scheme known as a low-complexity multiuser detection method for DS/CDMA systems. The proposal system has been analyzed by taking into account the error in previous cancellation, and it is shown that the performance system (i.e. BER) with ideal effective power for all the users (-20 dBm) is improved at each stage of cancellation process.

Proposal of successive interference cancellation scheme in optical code-division multiple access systems

Proposes one of the multiuser detection schemes, a new technique that has the potential to reduce interference or suppress multiple-access interference and, therefore, increase the capacity of optical code-division multiple access (CDMA) systems. It is a successive interference cancellation (SIC) scheme known as a low-complexity multiuser detection method for direct sequence CDMA systems. A SIC scheme is analyzed using an optical orthogonal code, with a different power for each user, that takes into account the impact of imperfect interference cancellation.

Performance enhancement of successive interference cancellation scheme based on spectral amplitude coding for optical code-division multiple-access systems using Hadamard codes

A successive interference cancellation scheme is applied to optical code-division multiple-access OCDMA systems with spectral amplitude coding SAC. A detailed analysis of this system, with Had- amard codes used as signature sequences, is presented. The system can easily remove the effect of the strongest signal at each stage of the cancellation process. In addition, simulation of the prose system is per- formed in order to validate the theoretical results. The system shows a small bit error rate at a large number of active users compared to the SAC OCDMA system. Our results reveal that the proposed system is efficient in eliminating the effect of the multiple-user interference and in the enhancement of the overall performance.

Analysis of spectral amplitude coding OCDMA successive interference cancellation scheme

A successive interference cancellation optical (O-CDMA) system with spectral amplitude coding is investigated. It has been shown that SIC/SAC scheme has potential to suppress MAI, and improve the system performance as compared with conventional receiver.