APPLICATIONS OF ADVANCED DIGITAL SIGNAL PROCESSING TECHNIQUES FOR FAST CARRIER ACQUISITION
Tien M. Nguyen, Loc Van Lam, Henry-Geul Yeh
The Aerospace Corporation
2350 El Segundo Blvd.
El Segundo, California, USA
This paper proposes an open loop carrier frequency acquisition
technique for future digital receivers. The open loop frequency
acquisition technique proposed here is for residual-carrier signals,
and it is based on the detection and estimation of the received
carrier signal. The proposed technique can also be used for suppressed
carrier signal without modifications. The numerical results show that
the frequency error of the proposed frequency estimator depends
strongly on the received Carrier-to-Noise Ratio (CNR). This paper
also discusses two adaptive CNR enhancement techniques and CNR
estimator that when combined with the proposed frequency estimator
will produce an accurate estimate of the carrier frequency for fast
EVALUATING ERROR PROBABILITIES FOR MOBILE COMMUNICATION RECEIVERS
Tien Manh Nguyen
The Aerospace Corporation
2350 El Segundo Blvd.
El Segundo, California, USA
The paper explores various mathematical techniques to analyze the
performance of a BPSK receiver in the presence of Inter Symbol
Interference (ISI) plus Additive White Gaussian Noise (AWGN), slowly
fading channel plus AWGN, and ISI plus slowly fading and AWGN. Only
coherent detection of BPSK is considered in this presentation. It
will be shown that the Bit Error Rate (BER) performance in the
presence of ISI plus AWGN can be evaluated using standard mathematical
technique or numerical quadrature of a Laplace inversion integral
along a contour in the complex plane passing through a saddlepoint of
the integrand. The BER for slowly fading channel and AWGN can be
calculated by using series expression for the characteristic function
of the sufficient statistic and the results obtained will be compared
to the standard text book method. Furthermore, It will also be shown
that the BER performance in the presence of ISI plus slowly fading and
AWGN can be computed using series expression for the characteristic
function of the sufficient statistic and that, for this case, the
numerical quadrature method becomes more involve due to mathematical
complexity associated with it.
MOBILE COMPUTING OR WIRELESS COMPUTING
Ambekar Muralidhar Rao
B843, Bhagya Laxmi Nilaya
Bangalore 560 013
The word mobile computing always brings to our senses about a node being
mobile, how about thinking in much broader sense like that of the whole
network being mobile. The network being mobile means that it is always on
the move, not fixed to any place at any time. This case can exist in a ship
which is mobile(constantly moving from one place to another such as
Aeroplanes, some ships/boats etc.)
So we can think Mobile Computing to comprise of 2 aspects that are to be
resolved. They are as follows:
1. Mobility of a node
2. Mobility of a network.
The mobility can be considered at the micro and macro levels.
Mobility of a node:
It has been a problem when a mobile node moves from one network to another.
The problem begins with IP Address, the reason being the inflexibility in
IP Address. In Other words a node is identified relatively and not
absolutely (ie., A mobile node is identified with respect to its Network).
This makes it quite difficult when it comes to mobility factor of the
mobile node outside the network.
To overcome this difficulty it would be better if we could assign a unique
absolute Identification number to the mobile node with/without relating it
to the network where it has been registered. This unique Identification
number of the mobile node should not conflict with any Identification
number in the whole world. This would avoid a situation such as an IP in an
IP, that is generally being considered. IP in an IP does not solve the
problem completely but instead postpones the problem.
A mobile node is registered under only one Registration Authority. This
Registration Authority is got to answer any queries regarding the mobile
node. Any contact to this mobile node is done only after contacting the
Registration Authority. This Registration Authority should resolve the
mobile node's Address and should also specify the location by giving its
current network identification number. This helps in contacting the mobile
node. Whenever a mobile node moves from one network to another then the
mobile node should intimate its Registration Authority with the present
network id. This is the most important aspect in mobile/wireless computing.
This would definitely suffice all needs of any problem. The mobile node
should maintain/store the previous network id if it is moving to the new
network. This strategy is used to collect any uncollected messages from
the previous network. It means that the packets that have arrived at the
previous network is collected at a later time after the moving to the new
Mobility of a Network:
In this concept we can follow the same procedure as that followed by the
previous section "Mobility of the node". Here it is at macro level.
Consider an Aeroplane which has a network established in itself. This
network is always moving from one place to another. Here the routing is
quite difficult, and hence the reason to communicate is rendered useless.
For this kind of mobility we are to have some kind of information saying
where it's location is and so on.
NEW DIVIDER AND MULTIPLIER CIRCUITS FOR GALOIS FIELDS GF(2m)
Ying Ye and Son LeNgoc, IEEE Senior Member
Faculty of Engineering
St. John's, NFLD, A1B 3X5
Based on the paper , new bit-serial systolic circuits for division
and multiplication over GF(2m) are developed. The divider
requires three basic types of processors, one simple control signal
and regular and local interconnections. The structure is independent
of the bases (i.e.normal or standard basis) or the irreducible polynomials
chosen to generate the Galois field. The structure has a latency of 4m
clock cycles and a throughput rate of one result per m clock cycles. This
speed performance is much better than those of the previous implementations
reported. As compared to the related dividers presented by Hasan and
Bhargava , the proposed implementation is less complex and more efficient.
The multiplier uses part of the divider structure with m additional
simple processors. This will result in a reduction of area if fabricate
the divider and multiplier on a single chip.
AN OBJECT-ORIENTED APPROACH FOR VIDEO CODING AT BIT RATES BELOW 32 kbits/sec
Dam LeQuang and André Zaccarin
Dépt. de génie electrique et génie informatique
Ste-Foy, Quebec, Canada, G1K 7P4
Tel: (418) 656-2130, Fax: (418) 656-3159
Standard coding algorithms for video sequences, like H.261 and MPEG, are
based on a block-based motion compensation and a block-based DCT. However,
at very low bit rates, the performance of block-based coding algorithms is
not good. Object-oriented approach has been proposed to overcome the
weakness of block-based algorithms. Typically, object-oriented algorithms
segment each image into regions of uniform motion, compute their motion
parameters and encode the prediction error by efficient methods. In this
paper, we propose an object-oriented algorithms with 3 stages. In the first
stage, a block matching algorithm and a maximum a posteriori probability
estimate are used to compute a translational motion field and its segmentation.
Using that segmentation, we compute complex motion parameters in the second
stage. Each image is therefore described by 3 sets of parameters: motion
(M), segmentation (S) and prediction error (P) that must be efficiently
encoded by appropriate methods. Particularly, DWT is utilized for coding
low-correlated prediction error. Simulation results show that the proposed
algorithm significantly outperforms standard block-based algorithms while
keeping a low computational complexity.
A PC-BASED GENERAL PURPOSE REED-SOLOMON CODEC SIMULATOR
Son LeNgoc, Senior Memeber, IEEE, Tapas Banerjee, Ying Ye
This paper introduces a PC based general purpose Reed-Solomon (RS) CODEC
simulator for teaching as well as research purposes. The user can define
a code by selecting the symbol length, 3≤m≤8 its and the error
correcting capability T of up to 20. In the encoder, the systematic code
generation and the self-reciprocal generator polynomial are used. The
error pattern can either be entered by the user with the arbitrary weight
or generated by an external program which alternates all possible error
positions. In the decoding process, both Peterson's and Berlekamp's
algorithms are available for the user's choice. Chien Search is used for
finding the error locations. The error values can be obtained by using
either Gauss elimination or Forney's algorithm depending on the user's
selection. The simulator has break points and printing-out at every step
in encoding, error generating and decoding processes. The simulation
software runs in MS Windows operating systems and provides a friendly
and easy-to-use graphical user interface (GUI). This is an ideal
simulator for demonstrating the RS code encoding and decoding principle
in classrooms and laboratories.
PERFORMANCE ASPECT OF TREE-BASED INDEXING METHODS IN MULTIDIMENSIONAL DATABASES
Nguyen Tran and Bob Sier
Department of Computer Technology
Monash University, Australia
20 Livingstone Cl. Burwood, 3125, Australia
The management of spatial databases has become important with the emerging
of advanced applications in multimedia, robotics, CAD/CAM, geographic data,
and computer vision. Since such application require storage of high dimensional
data (from 10 to 100), the traditional indexing techniques are no longer
sufficient and as a result many spatial access methods have been proposed.
However, studies on spatial access methods particularly focus on the data
structures and algorithms, performances under the worst case may not be
predicted. In this paper, we examine some of the current tree-based methods,
and propose a methodology for evaluating the performance of tree-based indexing
techniques under the worst case. This allows better selection of indexing
techniques for applications without having to actually implementing and
experimenting the techniques.
A STRATEGIC FAB AUTOMATION CONTROL ARCHITECTURE
Mitta Technology Group, Inc.
Sunnyvale, California, USA
As the demand for semiconductor continues to grow, many semiconductor
foundries are either expanding their current fabs and/or building new ones.
The need for fab automation is becoming more mission critical than previously
considered. To address the requirements for a flexible manufacturing system
that supports fab wide automation, this paper describes a common factory
automation architecture based on our Mitta's past lessons-learned and
An ideal factory automation architecture shall not be dependent on any specific
vendor's tool and must be "totally open" to accommodate future product
changes of fab expansions. This paper will describe the foundation required
to develop various flexible Computer Integrated Manufacturing (CIM) applications
such as the Electronic Traveler Management, Quality System, and MES
The objective of this paper is to help the audience understand underline
technologies required for fab wide automation. Emerging technologies will
be discussed to automation engineers can "boot strap" their project using
these new technologies.
VPP-FORTRAN AND HARDWARE PERFORMANCE OF VPP500 DISTRIBUTED VECTOR-PARALLEL SUPERCOMPUTER
Thuy Trong Le and Jason Wang
Fujitsu America Incorporation
San Jose, CA 95134 USA
This paper describes Fujitsu VPP-Fortran and hardware performance of
Fujitsu VPP500 vector-parallel supercomputer. For a given system, knowledge
about the hardware performance of fundamental operations is essential for
the implementation of numerical methods, evaluation of various solution
schemes, and for the performance expectation in other relate type of
computations. With this reason, investigation of the hardware performance
and performance of vector/matrix operations on a specific parallel computer
are foundation for the implementation of parallel sparse matrix solvers.
This research is our first step in the attempt to specific good parallel
iterative sparse matrix computation schemes for Fujitsu VPP500 vector