KEYWORDS: Antennas, Monte Carlo methods, Wireless communications, Telecommunications, Computer simulations, Computing systems, Transmitters, Mobile devices, Network architectures, Signal to noise ratio
This paper focuses on the performance of cochannel interference (CCI) which is the primary
factor to limit the capacity of wireless communication systems. Several cellular network
architectures have been proposed in the literature to reduce the cochannel interference, but none
of them appears to effectively tackle this problem. Microzoning is the technique, where the cells
are further divided into smaller zones. The advantage of this technique is that the cochannel
interference in the cellular system is reduced because the cell maintains a particular coverage
radius. The objective of this paper is to analyze the performance of cochannel interference on the
forward channels of the proposed microzone based CDMA cellular systems operating with
perfect power control in an effort to reduce the cochannel interference. Simulation results
showed that the proposed technique can effectively minimize cochannel interference and the
proposed architecture can be used for practical applications.
Image processing is a field of great interest for many applications. Nowadays it is very hard to name an
application where image processing is not involved. Digital techniques remains the dominant ones applied
to digital image processing with significant automation approaches that are built in image display, as in
most digital cameras and digital TVs, to name few. Depending on the application, digital image
processing techniques produces satisfactory accurate results. However, digital enhancement techniques
suffer from the main constraint: slow processing speed, an inherited problem associated with any digital
image processing technique. On the other hand optical image enhancement techniques such as the
polarization-based ones produce satisfactory accurate results and at the same time overcome the
processing time constraint associated with their digital counter ones. This paper presents a comparison
between digital and polarization-based enhancement/encoding techniques with respect to their accuracy,
security and processing time in automated pattern recognition applications.
Fingerprint recognition is one of the most commonly used forms of biometrics and has been widely used in daily life
due to its feasibility, distinctiveness, permanence, accuracy, reliability, and acceptability. Besides cost, issues related to
accuracy, security, and processing time in practical biometric recognition systems represent the most critical factors that
makes these systems widely acceptable. Accurate and secure biometric systems often require sophisticated enhancement
and encoding techniques that burdens the overall processing time of the system. In this paper we present a comparison
between common digital and optical enhancementencoding techniques with respect to their accuracy, security and
processing time, when applied to biometric fingerprint systems.
KEYWORDS: Antennas, Monte Carlo methods, Wireless communications, Telecommunications, Transmitters, Mobile devices, Computing systems, Computer simulations, Network architectures, Signal to noise ratio
This paper focuses on the performance of cochannel interference (CCI) which is the primary
factor to limit the capacity of wireless communication systems. Several cellular network
architectures have been proposed in the literature to reduce the cochannel interference, but none
of them appears to effectively tackle this problem. Microzoning is the technique, where the cells
are further divided into smaller zones. The advantage of this technique is that the cochannel
interference in the cellular system is reduced because the cell maintains a particular coverage
radius. The objective of this paper is to analyze the performance of cochannel interference on the
reverse channels of the proposed microzone based CDMA cellular systems operating with
perfect power control in an effort to reduce the cochannel interference. Simulation results
showed that the proposed technique can effectively minimize cochannel interference and the
proposed architecture can be used for practical applications.
Fingerprint recognition is one of the first techniques used for automatically identifying people and today it is still one of
the most popular and effective biometric techniques. With this increase in fingerprint biometric uses, issues related to
accuracy, security and processing time are major challenges facing the fingerprint recognition systems. Previous work
has shown that polarization enhancementencoding of fingerprint patterns increase the accuracy and security of
fingerprint systems without burdening the processing time. This is mainly due to the fact that polarization
enhancementencoding is inherently a hardware process and does not have detrimental time delay effect on the overall
process. Unpolarized images, however, posses a high visual contrast and when fused (without digital enhancement)
properly with polarized ones, is shown to increase the recognition accuracy and security of the biometric system without
any significant processing time delay.
Efficient recognition and clearance of subsurface land mine patterns has been one of the challenging humanitarian
and military tasks. Among the several subsurface land mine patterns recognition techniques available, passive
imaging techniques are more convenient, safer with good probability of recognition. There exist extensive
applications where the joint-transform correlation algorithms have been used for efficient pattern recognition.
However, among the several pattern recognition algorithms exist for subsurface land mines, the joint-transform
correlation ones has been underrepresented. This paper presents the application of an efficient wavelet-filter joint
transform correlation (WFJTC) algorithm for the recognition of passive imagery of subsurface land mines in highly
cluttered scenarios, using intensity and polarization-based imagery. We further improve the recognition efficiency of
the WFJTC proposing a combined optical-digital enhancement approach. Improvements will be justified using
correlation performance metrics.
Fingerprints recognition systems have been widely used by financial institutions, law enforcement, border control, visa
issuing, just to mention few. Biometric identifiers can be counterfeited, but considered more reliable and secure
compared to traditional ID cards or personal passwords methods. Fingerprint pattern fusion improves the performance of
a fingerprint recognition system in terms of accuracy and security. This paper presents digital enhancement and fusion
approaches that improve the biometric of the fingerprint recognition system. It is a two-step approach. In the first step
raw fingerprint images are enhanced using high-frequency-emphasis filtering (HFEF). The second step is a simple linear
fusion process between the raw images and the HFEF ones. It is shown that the proposed approach increases the
verification and identification of the fingerprint biometric recognition system, where any improvement is justified using
the correlation performance metrics of the matching algorithm.
Over the past few years, several wireless location detection algorithms have been proposed in the literature.
However, an effective solution for CDMA-based wireless communication system is yet to be found. In this paper, a
position location estimation technique for CDMA wireless communications system is proposed. The proposed technique
utilizes the Chan-Ho method for solving the hyperbolic model, which provides faster solution to the hyperbolic model
and does not suffer from the convergence problem. The performance of the proposed position location technique has
been tested by considering different system parameters, such as channel noise and variable position of the user. Test
results show that the proposed position location technique can successfully determine the position of a wireless user
under various challenging scenarios.
Fingerprint recognition applications as means of identity authentication that deals with accuracy and security are
becoming more acceptable in areas such as financial transactions, access to secured buildings, commercial driver license
and identity check at entry borders, to mention a few. This paper presented a new approach of using two patterns of the
same person, intelligently fused, to form a new unique pattern of the same person. The Laplacian pyramid (LP) level 7
image fusion approach and the logical "OR" and logical "AND" operators for the decision fusion approach were tested
with respect to their performance in accuracy, security and processing speed of the recognition system. The concept of
receiver operator characteristic (ROC) curve to indicate any improvement in accuracy and security of the process was
used.
Finally, an overall comparison and analysis of performance between traditional systems that used a single pattern
and our proposed system that used two fused fingerprint patterns in the biometric system was presented.
The demand for bandwidth for applications in high-speed networks requires improved network topologies,
throughput, and parallelism. Many techniques such as optical code-division multiple access (CDMA), wavelength
division multiple access (WDMA) and dense WDMA (DWDMA), have shown considerable potential for high-speed
network applications. This paper evaluates the performance of these techniques with respect to bandwidth utilization and
delay under various scenarios. Simulation results showed that optical CDMA system emerges as the most efficient
system because CDMA utilization is the highest when compared to the WDMA and DWDMA systems, and that CDMA
is better for high offered loads compared to WDMA and DWDMA.
Several approaches have been presented to enhance the recognition capabilities of certain patterns. This is
particularly important in applications involve recognizing the identity of some individual accurately, especially in
critical applications such as border entry, access to secured buildings, and in financial transactions, among other
things. In this paper, we present an approach to improve the accuracy of a biometric recognition system using two
fused patterns (two fingers) of same classifier (individual). In this method, two or more fingers of the same classifier
are fused together to form a unique fingerprint pattern to be used in the recognition process. Techniques related to
pattern and decision fusions are tested. In particular, the logical AND operator used in the decision fusion algorithm
has resulted in a higher level of accuracy of recognition.
This paper aims to analyze the QoS performance of two main technology mechanisms, Multi-Protocol
Label Switching (MPLS) and Differentiated Services (DS). The introduction of both mechanisms to
support throughput and delay sensitive real-time media traffic will have an impact on critical applications
with respect to QoS and traffic engineering. MPLS is a traffic forwarding mechanism that allows traffic to
use multiple paths and DS is a mechanism that provides for aggregate traffic to be classified and
conditioned at the edge of the network routers.
The two modeled techniques and their performance will be evaluated with respect to their end-to-end delay.
The QoS will be incorporated in both the MPLS and DS mechanisms while preserving the efficiencies of
the backbone structure of the Internet, and also the performance is compared with the existing IP routing
algorithms.
This paper presents a new method which enhances the quality-of-service (QoS) and hence the response time and
queuing delay of real-time interactive multimedia over the Internet. A service class based on differentiated services
mechanism has been developed. Evaluation of response time under different traffic conditions has been conducted via
simulation. Specifically, the impact on routers performance at the boundary of a DS-enabled domain was evaluated
using OPNET and the results are presented. Since audio and video traffic have different needs, priority schemes for
different types of interactive multimedia traffic have been studied to provide control and predictable service, and
therefore, better quality of service.
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