Minimum Shift Keying (MSK) by pptfiles

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									                             Minimum Shift Keying (MSK)

                            By: Vinod Ananthapadmanabhan

The topic of this research paper discusses the evolution of MSK from other encoding
techniques such as FSK, QPSK and OQPSK. A brief description of its working will also
be covered. It will include how MSK offers effective bandwidth use without some of the
disadvantages of FSK. Special emphasis will be laid on explaining why it is called
“Minimum” shift keying. It will also include a list of comparative criteria for each of the
four techniques named above. The current use of Gaussian Minimum Shift Keying
(GMSK) in GSM systems and other areas will be pertinently explained. Finally the future
use of MSK will be discussed as well as other future technologies.



                   Technical Aspects of the GPS C/A Code Signals

                                   By: Jonathan Buck

This research paper will discuss the GPS C/A code signal structure along with some
fundamental acquisition requirements and techniques. The properties of the C/A code
and the actual data that is transmitted by this C/A code will be discussed. The basics of a
GPS receiver will be presented, specifically how signal acquisition can be performed.
The main focus of the paper will be to show the usefulness of the spread spectrum signals
for transmitting data (CDMA signals, bi-phase modulation). It will also be important to
give a quick overview of the operational theory of GPS (the satellite constellation and
how a location can be determined).



         Gold’s Frequency Hopping Communication System and Algorithm

                                   By: Cliff Bullmaster

This research paper will discuss several aspects of Robert Gold’s frequency hopping
comm. system. Beginning with the hardware, the paper will explain the reconfigurable
settings of the transmitter. Multiple PN sequences can be implemented in the system by
changing them with Gold’s software on a laptop. Then, although the specific formulas of
the system’s algorithm are proprietary, this paper will explain what the algorithm does,
and the basics of its performance. Finally, the paper will explore possible weaknesses in
the system, and will propose and document an experiment to try to prevent the system
from functioning as it was designed to.
                            Technical Description of WiMax

                                      By Peter Buxa

WiMax is a new wireless technology that is intended for wireless metropolitan area
networks (MANs). WiMax, also known as IEEE 802.16, is meant for broadband wireless
in distances of miles. WiMax is a second-generation protocol to the WiFi/802.11
protocol found in homes and businesses today. This paper will produce a technical
description of the new WiMax technology and attempt to explain why it allows for more
efficient bandwidth use, interference avoidance, and higher data rates over longer
distances compared to the already established WiFi/802.11 standard.



                  802.11(a), (b) and (g) IEEE Standards for WLAN

                                    By: Padmini Desai

This research paper will discuss a detailed description of 802.11(a), (b) and (g) IEEE
standards for Wireless Local Area Network (WLAN). The research paper will begin with
a brief introduction of 802.11 standard followed by topics like spread spectrum
techniques, protocols, modulation schemes used by all the three standards. This paper
will also include comparison of the three standards. Finally, this paper will be concluded
by suggestions for further study.



                                Effects of UWB on GPS

                                   By: Ronald Frank

The purpose of this study is to determine the effects of UWB on GPS and whether the
theories and implementation of previous tests were accurate and sufficient. This report
begins with a brief description of UWB including the theory and probable
implementation of UWB communication systems. This report will follow with a
description of how GPS hardware receivers perform correlation functions and how UWB
interferes with these processes. The testing section explains the significance of each test
performed, and the motivation for each test. The test section includes a description of the
significance of each recorded result. The report concludes with recommendations for
further testing and suggestions to make UWB more likely to coexist safely with GPS.
                Ultra-Wideband Electromagnetic Target Identification

                                    By: Henry Griffith

There is currently a strong interest in the application of ultra-wideband (UWB)
technology to the problem of electromagnetic target identification. In general,
electromagnetic target identification is the process of obtaining information about a target
from the scattering of the transmitted electromagnetic wave by a sensor due to the target
itself. From an electromagnetic imaging standpoint, it is understood from applications in
such fields as medicine that effective imaging can by obtained by rotating the sensor
completely around the target of interest. However, in most radar applications, the rotation
of the sensor is often not feasible. In fact, the most common radar systems implement a
monostatic approach, wherein the receiver and transmitter are fixed at a single location.
In conducting such a monostatic interrogation, one inherently looses a great amount of
information about the target, namely the spatial degrees of freedom involved in the
interrogation. The purpose of this research will be to explore current work which attempts
to partially regain some of the lost identification information by using UWB transmitted
signals. Since UWB systems transmit signals over a much wider frequency band than
conventional systems (usually at least 25% of the center frequency), one can attempt to
regain the loss of information due to restrictions in space by adding degrees of freedom in
bandwidth. Other issues to be examined in this study will be the issue of target size as it
relates to bandwidth. Performing an analytical analysis of the problem might specify the
amount of bandwidth needed to detect a target as a function of size. UWB technology is
relevant to the general course topic of spread spectrum technology since it could be
classified as a spread spectrum technique itself due to the fact that it utilizes an amount of
bandwidth greater than that which is necessary to transmit the information itself. This is
one of the defining characteristics of a spread spectrum system Deliverables of this
project will include both a power-point presentation, as well as a written report, to be
delivered to the instructor on the dates specified in his website. A briefing of the results
will be given during the 8th week of the course as well.



                        Quadrature Phase Shift Keying (QPSK)

                                    By: Manasi Kakade

This special research paper will focus on the Quadrature Phase Shift Keying (QPSK)
modulation scheme used in direct sequence spread spectrum. It will discuss the theory,
i.e. modulation, demodulation, signal constellation and error probability as it applies to
QPSK in detail. It will also involve the discussion on the advantages and disadvantages
of using it in the spread spectrum systems and touch on the Offset-QPSK.
                              Ultra Wideband Technology

                                  By : Patrick Karamaga

The Ultra Wideband technology paper will discuss the concept of remote sensing. The
difference between UWB radar and Conventional radars will be covered. The paper will
discuss the features of UWB radars. It will also discuss signal detection and
identification, radar reflection characteristics and Cross section specifications. The paper
will discuss in details the performance estimation, compression of wideband signals and
UWB random noise signal. UWB Signal Processing, its capabilities and high power
UWB radar systems will also be discussed. The research paper will conclude in
discussing future Radars technology and recommendations of further studies on this
topic.



                            OFDM Simulation using Matlab

                                  By: Andrew Kondrath

OFDM is an acronym for orthogonal frequency division multiplexing. It is part of the
modulation scheme used in the 802.11g standard. This paper will discuss how OFDM is
implemented and used in wireless networks. It will also discuss a simulation of such a
system using MatLab. The MatLab simulation will encode the data using differential
binary phase shift keying and section off the data into blocks for transmission via OFDM.
White Gaussian noise will be added to the transmission signal in order to represent
channel effects.


                                   3G Cellular Systems

                                    By: Arun Kulkarni

This research paper will present the evolution of third generation cellular mobile systems.
The CDMA spread spectrum system will be explained in detail. The paper will discuss
the CDMA coding principles, the generation of Walsh codes (long & short), and the
subsequent use of these codes as PN code sequences. The CDMA system architecture,
power control mechanisms, signal structures and channel capacities for CDMA will also
be presented. Some information on the migration of 3G systems from 2G technologies as
GSM and IS-95 will be provided. Moreover, the underlying technologies currently used
to implement 3G systems as well as their future scope including 3xRTT and IxEV-DO
will be described. In conclusion, the paper will also briefly introduce the next generation
of wireless systems (4G) and the integration of 3G and 4G systems.
 Performance of Spread Spectrum Techniques in Various Jamming Environments
                        Through Software Simulation

                                   By: Todd Malicki

The scope of this paper will discuss the results of software modeling and simulation of
spread spectrum (SS) systems while in the presence of interference sources. Three
spreading techniques will be compared: Direct Sequence (DS), Frequency Hopping (FH)
and Time Hopping (TH). For modeling and simulation of these techniques, various
parameters will be changed in order to observe the impact on system performance (i.e.
overall Bit-error rate (BER)). For example, using DS, how the chipping rate effects the
performance in the presence of interference sources. Similarly, for FH and TH, how does
varying the hopping rate effect the BER. Different types of interference sources will also
be explored, such as single frequency (CW) jammers, broad-band jammers which cover
all or part of the desired SS bandwidth, and some so-called “smart jammers” which are
designed to attack specific aspects of the SS system (such as a replica chipping code).
The advantages/disadvantages of each SS technique based on the results of the
simulations will be explored.




   A Study on FPGA implementations of Pseudo-random Noise code Generators

                                   By: Ramesh Papala

This research paper will be a study project to find, partly/fully implement and discuss
advantages, disadvantages and difficulties in implementation of Pseudo Random Noise
Generators using FPGA. The aim of this study project is to study the concepts of PN
Generators in as much as in detail as possible, practice HDL coding, work on FPGA and
implement a PN sequence and at least one Product code. The start of the project will
implement a LFSR similar to the one discussed in class with what possible resources at
hand, on successful implementation a move would be made to implementation of Gold
codes after satisfactory completion of Gold codes work would go for codes like Kasami
codes. HDL coding will be done only after a successful implementation in a schematic
editor. The design, theory, mathematics, properties, advantages, application, HDL code
and circuit diagram of each PN Generator implemented would be discussed during turn-
in.
                                  Multicarrier CDMA

                                   By: Kirti Penmetsa

This paper discusses the evolution of multicarrier (MC) - CDMA by going over the
disadvantages of DS-CDMA and OFDM. The paper will also present how the
multicarrier modulation takes place and how it could help in extending the capacity of the
CDMA cellular systems. The transmitter and receiver optimization is also discussed. In
the end, the new concept of Multicode MC-CDMA (MC-MC-CDMA) which
outperforms MC-CDMA is discussed.



                  Global System For Mobile Communication
                               By: Keerthana Ramanujam

This paper will present a technological overview of the modulations in GSM. The paper
will include modulations like shift keying, from QPSK to MSK, GMSK. The paper will
be concluded with comments regarding the scope for further study and research about
GSM.




                 Wideband Code Division Multiple Access (W-CDMA)

                                  By: Saurabh Ranade

This technical paper addresses Wideband Code Division Multiple Access (W-CDMA)
with a primary focus on the Air Interface Procedures involved in W-CDMA
transmissions, namely cell search, handover, power control, uplink synchronous
transmission schemes and packet data. This research paper briefly discusses the origin of
WCDMA followed by the basic working principle. Subsequently the specifications of W-
CDMA and a narrative about the Air Interface Procedures follow, along with some
WCDMA terminology. This paper is concluded with comments and suggestions about
the future of W-CDMA and possibilities for further study.
                          Ultra-Wideband (UWB) Technology

                                      By: Scott Rieck

This research paper will discuss Ultra-Wideband (UWB) Technology and how it works
with spread spectrum systems. Many of the advantages will be looked at such as the low
required energy while using higher bit rates. This paper will present what Ultra-
Wideband technology is and why such a wide frequency range is used. Also, the
difficulty of detection will be discussed. It will also look at the use of this technology in
wireless LAN’s, radar, and other communication systems.




                     Techniques of Jamming and Anti-Jamming of
                      Spread Spectrum Communications Systems

                                    By: Philip Robinson

Spread spectrum communication systems change the face electronic warfare immensely.
Because of spread spectrums systems inherent anti-jamming traits, jamming technique
was force to evolve. In this research paper, the techniques of jamming spread spectrum
communication system will be discussed, Include such techniques as wide-band radio
frequency spectrum transmitters, several keying techniques, and other more sophisticated
systems comprised of frequency tracking receivers and transmitters. It will also discuss
the counter-measure implement to prevent jamming, Such as adaptive filtering, time-
frequency domain filtering, subspace processing and amplitude domain filtering. This
paper will summary the measure and counter-measure in jamming techniques that spread
spectrum communication system created since its implementation in the electronic
warfare genre.


                   Comparison of CDMA/FDMA/TDMA Capacities

                                     By: Parag Singhai

This technical paper addresses the comparison of various multiple access techniques such
as CDMA/TDMA/FDMA etc. The focus of this paper is the differences in the protocols,
capacity, spectrum allocation and architectures. The paper starts with a brief description
of each system followed by the narrative which addresses the special topic in greater
detail. The paper also gives suggestions for further study on the same.
                     Transform Domain Modulation Techniques

                                   By: Om Vadlapatla

An introduction to the concept of designing communication waveforms in frequency
domain will be presented. The significance of this mechanism of modulation in terms of
its applicability to use the allocated but unused or idle bandwidth will be discussed. One
implementation approach (Cyclic Shift Keying) will be discussed. A literature survey to
compile a comprehensive source of information and bibliography for this topic will be
performed. The scope and future of this technology and its scientific significance will be
explained indicating current work and expected future trends.



                  Comparison of CDMA/TDMA/FDMA Capacities

                                     By: Mike Wier

With the proliferation of wireless technologies such as wireless networks, cordless
phones, and especially cell phones, capacities of these applications will continue to grow
in importance. This paper will explore the history of use of the three multiplex schemes
and describe where they each have a place. It will also address the theoretical limits of
each scheme’s capacity, given the bandwidths of the information to be conveyed and the
available RF spectrum. Finally, it will suggest where problems may lie in the future as
the demand for wireless bandwidth progresses from the 4Khz required for voice to
multiple megahertz bandwidths required for video and data.


             Comparison Of Frequency Hopping versus Direct Sequence

                                   By:   Ramesh Ragi

This research paper will discuss two important spread spectrum techniques so called
frequency hopping spread spectrum and direct sequence spread spectrum. Though both
modulation techniques agree with low power spectral density and redundancy there are
some issues that differentiate the performance of frequency hopper over direct sequence
or vice versa. The issues relating to comparison of frequency hopping and direct
sequence are system collaction, interference immunity, throughput, the near/far problem,
multipath immunity, time and frequency diversity, security, synchronization and timing
and security. The above said issues will be discussed and compared in detail. Finally a
conclusion is drawn as for which technique is preferred for each issue discussed.
                           Schedule for Research Topics



Monday, 16 May 2005                         Wednesday, 18 May 2005

1. Vinod Ananthapadmanabh:                  1. Arun Kulkarni: “3G Cellular
   “Minimum Shift Keying (MSK)”                Systems”

2. Johnathan Buck: “Technical Aspects       2. Todd Malicki: “ Performance of
   of the GPS C/A Code Signals”                Spread Spectrum Techniques in
                                               Various Jamming Environments
3. Clifton Bullmaster: “Gold’s                 Through Software Simulation”
   Frequency Hopping Communication
   System and Algorithm”                    3. Ramesh Papala: “A Study on FPGA
                                               implementations of Pseudo-random
4. Peter Buxa: “Technical Description          Noise code Generators”
   of WiMax”
                                            4. Kirti Penmetsa: “Multicarrier
5. Padmini Desai: “802.11(a), (b) and          CDMA”
   (g) IEEE Standards for WLAN”
                                            5. Ramesh Ragi: “Comparison Of
6. Ronald Frank: “Effects of UWB on            Frequency Hopping versus Direct
   GPS”                                        Sequence”

7. Henry Griffith: “Ultra-Wideband          6. Keerthana Ramanujam: “Global
   Electromagnetic Target                      System For Mobile Communication”
   Identification”
                                            7. Saurabh Ranade: “Wideband Code
8. Manasi Kakade: “Quadrature Phase            Division Multiple Access (W-
   Shift Keying (QPSK)                         CDMA)”

9. Patrick Karamaga: “Ultra Wideband        8. Scott Rieck” “Ultra-Wideband
   Technology”                                 (UWB) Technology”

10. Andrew Kondrath: “OFDM                  9. Philip Robinson: “Techniques of
    Simulation using MatLab”                   Jamming and Anti-Jamming of
                                               Spread Spectrum Communications
11. Mike Wier: “Comparison of                  Systems”
    CDMA/TDMA/FDMA Capacities”
                                            10. Parag Singhai: “Comparison of
                                                CDMA/FDMA/TDMA Capacities”

                                            11. Om Vadlapatla: “Transform Domain
                                                Modulation Techniques”

								
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