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In this paper, the performance of Optical Code Division Multiple Access (OCDMA) system is analyzed at different receivers by using Optical Orthogonal Codes (OOCs). Performance analysis is considered for the chip-level detector and optimum receiver. Our results demonstrate that optimum receiver require less BER i.e. 5.70e-008 than chip-level detector i.e. 2.54e-007 for fixed number of users i.e. for...
Code division multiple access (CDMA) utilizes spread spectrum techniques and has been widely deployed in wireless communications. Two major types of spread spectrum multiple access (SSMA) schemes are: i. direct sequence spread spectrum (DSSS) and ii. frequency hopped multiple access (FHMA). The benefits and technical advantages of CDMA could be translated in the optical-CDMA (OCDMA) for faster data...
RAKE receiver is used in CDMA-based (code division multiple access) systems and can combine multipath components, which are time-delayed versions of the original signal transmission. Combining is done in order to improve the signal to noise ratio at the receiver. RAKE receiver attempts to collect the time-shifted versions of the original signal by providing a separate correlation receiver for each...
In this paper, performance of ideal cross correlated ZCC code is investigated to support different multimedia applications with variable data rates and quality of service requirements in terms of signal to noise ratio and bit error rate. Simplicity in code construction and flexibility in Cross Correlation control has made this code a compelling candidate for future OCDMA applications. Further, various...
In this paper, we propose and analyze a novel multicarrier (MC) multicode (MCD) code-division multiple-access (CDMA) system employing wavelet packets (WPs) for modulation. This system can achieve robust performance against multipath fading due to the localization of WPs in the time and frequency domains. The analytical framework is presented, and the system performance with diversity is evaluated...
This paper describes a proposed spreading method to improve the bit error rate (BER) and user capacity in WCDMA system. The method is applied to the system up-link. The spreading process includes a new proposed random matrix constructed using the Walsh code generator, called randmat spreading code generator. Conventionally, the selection of the Walsh seed is highly dependable on the spreading factor...
The bit error rate (BER) performance for uplink quasi-synchronous code division multiple access system using different sets of orthogonal polyphase sequences is analyzed in this paper. The BER performance is evaluated in AWGN and flat Rayleigh fading channels. Correlation functions of some sequence sets are also compared. It is shown that LS-UCHT sequences have better autocorrelation properties as...
Wireless sensor networks consist of a large number sensors spread across a given geographical area. Each sensor has its own communication capability as well as certain level of intelligence for signal processing and networking. As the sensor nodes are densely populated, communication range requirement for these nodes is smaller. After signal detection, a number of sensor nodes communicate over the...
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