Wireless Sensor Networks

Wireless Sensor Networks
Wireless sensor networks typically consist of a large number of sensor nodes with limited onboard
battery resources which are difficult to recharge or replace. Thus the reduction of energy
consumption for end–to–end data rate and maximization of network lifetime have become chief
research concern. In recent years, many techniques have been proposed for improving the energy
efficiency in wireless sensor networks. Among these techniques, V–MIMO technique has been
considered as one of the effective ways to save energy. In WSN a node has two communication
related energy consuming roles, one role is to serve as a packet generating source node (SN), and the
other role is to relay packets for the other nodes, which are both energy consuming operations. This
is why the energy minimization is required to extend the lifetime of the WSN.
WSN nodes are commonly designed to communicate using single–input–single–output (SISO)
technology using a single transceiver antenna. Multiple–input–multiple–output (MIMO) with space–
time block codes is a communication method that uses multiple antenna to enable lower power
long–distance wireless communication over multipath fading channel. It may impossible to apply
MIMO technology to small WSN devices since small sensor nodes may only be able to have a
single antenna. Therefore, through collaboration of several single–antenna–equipped devices, a
cooperative MIMO technique called virtual MIMO (V–MIMO) has been proposed in [4].
The single–hop energy
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Summary : ' Subcarrier Allocation ' Square
Figure 3.6 Waveforms of the QPSK mapping. 3.1.4 Subcarrier Allocation There are three reasons for
outlining the "Subcarrier Allocation" square. The principal is to apportion the information and pilot
subcarriers, the second is to embed invalid subcarriers which conveys "zero" data, and the third is to
execute the FFT shift. After this square, 64 inputs for IFFT are readied. The execution module is
portrayed in Figure 3.7. Two 64 x 16 double port irregular access recollections (RAMs) are utilized.
The invalid subcarriers are accomplished by characterizing the substance of the two RAMs at
relative locations to be zeros. Ports An of the RAMs are utilized for information transporter
composing, while ports B are committed for pilot composing and the 64–subcarrier perusing. They
are controlled by two counters. "Counter_We_48" square stores the 48 information transporter
positions. As per the locations indicated by it, the I and Q estimations of the information images are
built into two RAMs from ports A. In the meantime, FFT movement is inalienably performed.
"Counter_Rd_64" utilizes a counter to create the perusing locations of ports B. At the point when
ports B are empowered and "Counter_Rd_64" tallies from 0 to 63, the coveted 64 inputs for IFFT
are yielded and the "en_ifft" is high, telling the IFFT square to perform figuring. Figure 3.7
Implementation module of Subcarrier Allocation. The perusing ought to begin after the written work
is done. In this way, the yield of

Integration Of Wireless Lan And Wide Area Network
4G is the integration of wireless LAN and Wide Area Network providing 100MHz for mobile and
1GHz for stationary devices. It uses packet switching networking and is based on Orthogonal
Frequency Division Multiplexing Access (OFDMA) technology. Wireless LANs soon will begin
multiplying or more in throughput and range if a smart antenna technology named MIMO works out
as its benefactors foresee.
The Third Generation Partnership Project (3GPP) Evolved Universal Terrestial Radio Access (E–
UTRA) Long Term Evolution (LTE) principles are a piece of 3G advancements. Multi–input,multi –
output (MIMO) has turned into a key innovation to enhance communication over a wireless channel.
With constrained spectrum, MIMO procedures attain to least target cell spectral proficiency, peak
spectral effectiveness and cell edge client spectral efficiency which are the base necessities indicated
by the ITU.
4G allows IP–based voice, information and streaming multimedia at higher speeds and offers no less
than 100 Mbit/s with high versatility and up to 1GBit/s with low portability (traveling). Various
advancements thought to be 4G measures incorporate Long Term Evolution (LTE), Ultra Mobile
Broadband (UMB) and the IEEE 802.16 (WiMax) standard. At the point when utilized as a part of
MIMO frameworks it would have the capacity to give high information rate up to 100Mbps
furthermore give QoS and Security administrations to end clients. The 4G goal is to meet difficulties
displayed by the perpetually

What Is Downlink Mimo System
Downlink MIMO
For the downlink MIMO system configurations with two or four antennas has being considered. In
2x2 configurations there is baseline configuration with two antennas at the transmitter and two
antennas at the receiver. There are different modes has been predicted for MIMO antenna system
such as spatial multiplexing and transmit diversity and channel automatically select any scheme of
choice.
Spatial multiplexing
In spatial multiplexing scheme the different stream of data has been transmitted on the same
downlink resource block. As there is SU–MIMO (Single user MIMO) and MU–MIMO (Multiuser
MIMO) and the data stream could be related to one of these. SU–MIMO is used to achieve higher
data rate whereas on the other hand MU–MIMO is ... Show more content on Helpwriting.net ...
Precoding matrix principle
The precoding matrix has been chosen from the predefined codebook which is called eNodeB and
UE side. Mostly the unity pre–coding is used in which the precoding matrixes are unitary. The UE
chose the best pre–coding matrix by predicting the radio channel. This pre–coding matrix the further
provides the maximum capacity. On the uplink control channel the UE also provides the feedback
which shows the preferred pre–coding matrix. The optimum pre–coding matrix varies between each
resource block. Uplink MIMO Uplink
For uplink MIMO scheme is different from downlink MIMO. MU–MIMO is used for the uplink
MIMO. This is also called spatial domain multiple access (SDMA) in which multiple users can
transmit at the same time on the same resource block. The major benefit of this scheme is that it
only requires only one transmit antenna at UE side. The UE must have to follow the mutually
orthogonal pilot patterns as they using the same resource block. In the starting technique the UE
have two transmit antenna with only one transmit chain and amplifier and switch is used to choose
the antenna that is able to provide the best channel to the eNodeB
VII. Performance improvement in MIMO system
The performance improvement in MIMO systems could be achieved from array gain, diversity gain,
spatial multiplexing gain and the reduction in the interference. The advantages of these

Advantages And Disadvantages Of FDMA
Abstract: In this paper, we propose a design for multiple antenna full–duplex (FD) eNodeB (eNB)
and user equipment (UE) transceiver, based on recent progress in the area of self–interference
cancellation (SIC). For FD communication, .i.e., simultaneous in–band uplink and downlink
operation, same subcarriers are allocated to UE in both uplink and downlink. Hence, contrary to
traditional LTE, we propose using single–carrier frequency division multiple accesses (SC–FDMA)
for downlink along with the conventional method of using it for uplink. Taking advantage of
channel reciprocity in the case of FD communication and multiple antennas at eNB, use of singular
value decomposition (SVD) in the downlink allows multiple user (MU) to operate ... Show more
content on Helpwriting.net ...
This signal is then converted to the frequency domain by taking the N–point DFT, which is given

Cellular Wireless With Unlimited Numbers Of Base Station...
Summary of "Noncooperative Cellular Wireless with Unlimited Numbers of Base Station Antennas"
EE –584–Wireless Systems Security XIAN ZHANG Email: xzhang84@stevens.edu Fundamental
ideas and Issues paper addresses 1 Core ideas 1 2 Core ideas 2 3 Potential applications & future
opportunities created by the technology 4 Reference 5 Summary of Fundamental Ideas and Issues
Addresses The paper I read is "Noncooperative Cellular Wireless with Unlimited Numbers of Base
Station Antennas" written by Thomas L. Marzetta. This paper was published in IEEE
TRANSACTIONS ON WIRELESS COMMUNICATIONS, VOL. 9, NO.11, NOVEMBER 2010.
The pilot signal is a direct sequence spread spectrum signal continuously sending by the base
station. It makes the base station could send data in the forward–link and demodulate cell phone
signals in the reverse–link. The pilot signal is known as confessed, like 000000 or 111111. In
frequency re–use technology, we divide the space into several cells. Due to the same or correlated
pilot sequence re–use in contiguous cells, the base station will inadvertently send data to terminals
in other cells or collect and combine reverse–link signals from terminals in other cells when
processing. This is called pilot contamination. In this paper, the author mainly talk about the
environment of multi–user(MIMO) operation with an infinite number antennas in the base station.
He thinks that in this

Green communication, emphasizing high energy efficiency in...
Green communication, emphasizing high energy efficiency in addition to traditional performance
metrics such as spectral efficiency and bit error rate [1]–[3], is becoming a mainstream in both
academia and wireless communication industry. This is perhaps due to two reasons. First, with the
increasing demand for hand–held wireless devices and the related high quality of service (QoS)
applications such as seamless world–wide network access, more and more energy consumption
gives rise to greenhouse gas emission and other environmental issues. Second, the slow growth in
the capacity of the wireless terminal batteries cannot meet the requirement of high energy
consumption, making the battery disposal problem more critical. Therefore, the high ... Show more
The single relay scenario has been extended to the multiple relay case. A single–relay selection
scheme from multiple SISO relays was proposed in [10] to minimize the energy consumption of
each data packet. In a tutorial article [11], some energy efficient approaches of MIMO techniques
for the enhanced IEEE 802.11a communications without using any relays have been reviewed. A
randomized scheduling policy is proposed to pursue the high energy efficiency in the point–to–point
MIMO downlink channels using the singular value decomposition technique [12], which is then
extended to multi–user systems in [13]. For single–relay systems, several pieces of work are
observed. For example, a lower bound of the energy efficiency function is derived based on
information theory in [14], a high energy efficient power allocation scheme is designed in [15]. The
three–node relaying system with each node having a single antenna, has been generalized by some
researchers to multi–relaying systems, with an objective of obtaining high energy efficiency. In [16],
an analytical expression is derived for optimum power allocation design based on the minimization
of per–bit energy in point–to–point MIMO systems, where the performance of the derived minimum
per–bit energy strategy is also analyzed. A joint cross–layer cooperative technique has been
developed to minimize the consumed energy [17]. In

Ordered Successive Interference Cancellation ( Osic ) Is...
Abstract– In this paper, ordered successive interference cancellation (OSIC) is adopted with
minimum mean square error (MMSE) detection to enhance the multiple–input multiple–output
(MIMO) system performance. The optimum detection technique increases the system complexity
with improved error rate performance. Therefore, MMSE–OSIC detection is used which gives
reduced error rate compared to traditional MMSE with a considerable level of complexity. The
system performance is analyzed in a composite fading environment which deals with multipath and
shadowing, known as Weibull–gamma (WG) fading environment. Along with the composite fading,
a composite noise i.e. additive white generalized Gaussian noise (AWGGN) model is taken into
account to form various noise scenarios such as impulsive, Gamma, Laplacian, Gaussian and
uniform noise. Consequently, generalized Q– function is used to develop such noise scenario. The
average symbol error probability (ASEP) of MIMO system is computed for 16–quadrature
amplitude modulation (16–QAM) using MMSE–OSIC detection in WG fading with AWGGN.
Analytical expressions are evaluated in terms of Fox–H function (FHF). These expressions
demonstrate the best fit to simulation results.
Keywords– MIMO, MMSE–OSIC, WG fading, AWGGN, M–QAM, ASEP.
1. Introduction
In MIMO systems, spatial multiplexing is used for high data rate transmission and spatial diversity
is used to achieve reliable communication. However, there is a tradeoff between diversity and

4g Wireless Mobile Communication Networks
4G wireless mobile communication networks are been specified to support display, battery and
computational power etc. 4G wireless mobile communication networks should not focus on air
interface and data rate, but instead cover advance wireless mobile communication networks and
high speed wireless access system into different platforms.
The era of new wireless communication is evolving and it will soon penetrate into daily life and
change the way we live. The key concept is integrating the 4g capabilities with all of the existing
mobile technology. The purpose of this paper is to provide an overview of different aspects of 4g
technology which include its features, proposed architecture and key technological enabler. 4G
technology will encompass all system from various network public to private operator driven
broadband to personal area and adhoc Networks. 4g technology system will be fully IP based
wireless internet. With 4G technology a range new services and model will be available, this
services and model need to be further examine for interface with the design of 4g technology
system. 4G wireless mobile communication networks are been specified to support display, battery
and computational power etc. 4G wireless mobile communication networks should not focus on air
high speed wireless access system into different platforms. Based on different model, 4G wireless
mobile

Paper Display The Adjusted Fix Radio Wire For 3ghz Recurrence
The paper display the adjusted fix radio wire for 3GHz recurrence, in the paper distinctive
methodologies is delivered by fluctuating opening and DGS into the reception apparatus, proposed
recieving wire gives double band operation and shows great recreated comes about for two
recurrence groups. Return loss of conclusive outline was – 11.75 dB for 3 GHz recurrence and
VSWR of 1.68 and – 17.86dB and VSWR of 1.28 for 5GHz frequency.[7] In the paper DGS is
utilized to builds the pick up and diminishes the misfortunes in the reception apparatus misfortunes
in the radio wire reductions to 16dB in the wake of applying DGS transfer speed of the recieving
wire is marginally lessened the proposed radio wire reproduced utilizing HFSS programming ...
Show more content on Helpwriting.net ...
[11] Paper is to outline an alternate microstrip fix recieving wire with Defect Ground Structure
(DGS) for productive rectenna plan. This reception apparatus having the property of high music
dismissal at undesirable frequencies at 2.0131GHz, and 2.457GHz, 2.565GHz as the composed
recurrence is 1.3 GHz and return misfortune is diminished around 43.17%by the DGS structure.[12]
An I–molded microstrip line is utilized to energize the square opening. The turned square opening is
inserted amidst the ground plane, and its slanting focuses are embedded amidst the strip line and
ground plane. To build the increase, four L–formed openings are scratched in the ground plane. The
deliberate outcomes demonstrate that the proposed structure holds a wide impedance data transfer
capacity of 88.07%, which is 20%better than the reference recieving wire. The normal pick up is
likewise expanded, which is around 4.17 dBi with a steady radiation design in the whole working
band. [13]. The proposed reception apparatus has little in size and works at 2.25GHz, 3.76GHz and
5.23GHz appropriate for versatile satellite administration (MSS) system, WiMAX and WLAN
applications ,In the paper, the plan of a coaxial nourish single layer rectangular microstrip fix
recieving wire for three diverse remote correspondence band

802. 11 Synthesis Essay
IEEE802.11n made numerous changes to the 802.11 wireless standards that greatly increased the
throughput as compared to earlier versions. 802.11n uses MIMO which is Multiple Input Multiple
Output (also known as Multiple Antennas). MIMO makes use of multiple antennae to create
multiple streams of communications between a transmitter and a receiver. The 802.11n amendment
also introduced changes in the physical as well as MAC layers to make marked changes in the
effectiveness of wireless networks. These changes included spatial–division multiplexing, space–
time block coding, and transmitter beamforming. Spatial–division multiplexing. This is the ability
for one transmitter to use multiple antennas to simultaneously send multiple ... Show more content
on Helpwriting.net ...
So the transmitter can increase the output of the antennas in the direction of computers farther away
or where there are more computers to allow for better coverage or throughput and decrease the
output of the antennas in directions where there are obstacles. Other changes in 802.11n include: 1.
40 Mhz bandwidth (channel bonding) which can get data rates as high as 600Mpbs which is a ten–
fold increase as compared with 802.11 a thru g. 2. Frame aggregation – transmits multiple MAC
frames in a PHY packet. 3. Reverse–direction protocol – allows the ability to transfer control of an
air channel between stations. This is especially good if the receiver is moving and the transmitters
are trying to keep the best connection possible. 4. Support for Voice over WLAN and multimedia
streaming. This is especially important as more telephone calls go VOIP and more video/audio
content is available online. 5. The ability of access points to change between 20 MHz and 40 MHz.
This is good as the receivers for that access point changes. The access point can speed up or slow
down based on the receivers in its broadcast area. 6. Channel bonding – using two 20MHz channels.
This turns the two 20 MHz band into a 40MHz band even though the transmitter is not transmitting
at 40MHz. This is good to increase throughput for receivers that only communicate at the 20MHz

Smart Antenna System Essay
INTRODUCTION
1.1 Antenna Systems:
Depending on the number of antennas used in the transmitting and receiving sections, the systems
are divided into 4 types.
1.1.1 SINGLE INPUT SINGLE OUTPUT (SISO): Fig 1.1.1: SISO
In SISO, there will be only single transmitter and a single receiver. This is the general system which
we use. The simplest antenna technology is SISO. In some environments, this system is vulnerable
to problems caused by multipath effects. When an electromagnetic field (EM field) is met with
obstructions such as hills, buildings, utility wires, and canyons the wavefronts are scattered, and thus
it take multi paths to reach the destination. Fading, cut–out (cliff effect), and intermittent reception
(picket fencing) are the problems caused by late arrival of scattered portion of signals. In a digital
communications system, it cause a reduction of data speed and number of errors is increased.
In order to eliminate or minimize problems caused by multipath wave propagation, a new
technology has been introduced and it is Smart Antenna Technology. There are three forms of smart
antenna, known as SIMO (single input, multiple output), MISO (multiple input, single output), and
MIMO (multiple input, multiple output).
1.1.2 SINGLE INPUT MULTIPLE OUTPUT (SIMO) : Fig 1.1.2 : SIMO
In SIMO, there will be only single transmitter and many receivers.
1.1.3. MULTIPLE INPUT MULTIPLE OUTPUT ( MISO): Fig. 1.1.3 : MISO
In MISO there will be multiple transmitters and a

A Study On Antenna Hopping
antenna hopping. In a system using antenna hopping, two or more transmit antennas are used
interchangeably to achieve a diversity effect. Antenna hopping attracted attention from 1990s and
comparatively in expansive way of achieving a transmit diversity gain in system such as GSM.
The principle goal of MIMO technology is to improve either the quality (BER) or the data rate of
the communication by means of adequate signal processing techniques at both ends of the system.
The capacity can increase linearly with the number of antennas when using MIMO system. MIMO
can obtain both multiplexing gain and diversity gain thus significantly increasing the system
capacity as well as improving the reliability of the wireless link. Having high spectral ... Show more
STCs necessitate the transmission of multiple redundant copies of data so that there is possibility of
receiving some copies of data through some are lost due to deep fading to enhance reliability of the
data transmission. STCs are two types namely space–time trellis codes (STTCs) and space–time
block codes (STBCs). STTC has been inaugurated as a coding technique that promises full diversity
and considerable coding
5
gain but decoding complexity is very high. To avoid this, STBCs have been proposed by the effort
work of Alamouti for transmit diversity and later Vahid Tarokh, Hamid Jafarkhani and Robert
Calderbank made their contributions.[1–3]. This code gives better second order diversity when used
with a single receive antenna and fourth order diversity when used with two antennas at the receiver
side. But, it is only half rate, because it only transmits two symbols using the two time slots and two
transmit antenna.
1.2 LITERATURE REVIEW
[1]S. M. Alamouti, describes a simple two–branch transmit diversity scheme. Using two transmit
antenna and one receive antenna, the new transmit antenna provides the same diversity order as
maximal–ratio receiver combining (MRRC) with one transmit and two receive antennas. The
scheme easily be generated to two transmit antenna and M receive antenna to provide a diversity
order of 2M. This scheme does not require any bandwidth expansion any feedback from the receiver
to the

What Are The Advantages And Disadvantages Of Multiple Antena
3.9.3 Advantages of multiple antenna systems
Array gain: Array gain is the average increase in the SNR at the receiver that arises from coherent
combining effect of Multiple Antennas. The signals arriving at the receiver have different
amplitudes and phases. The receiver can combine the signals coherently to enhance the resultant
signal. This can improve the reliability, and hence the capacity of the system.
Spatial Diversity (SD) gain: Signal power will fluctuate in a wireless channel. When signal power
drops significantly the channel is said to be in thefade. Diversity is used to combat fading. Spatial
diversity is the supply of multiple, independent copies of a signal at the receiver. Thus, we exploit
the rich scattering nature of the channel, ... Show more content on Helpwriting.net ...
6Else » 3–hop system is continued.
3.11 Genetic MIMO
In the genetic method, the chromosomes are the set of solutions for the optimization problems. Over
multiple iterations, these chromosomes crossover, mutate and evolve to get the optimal solutions. If
the chromosomes pass their solution as aparameter to the next order, then these chromosomes are
considered as fit. The genetic algorithm is defined below:
The initialization stage: A set of N chromosomes is randomly set. Each chromosome consists of a
vector K. This vector K indicates the schedule of the user. The user is scheduled if the value of K is
1 whereas the user is not scheduled if the value of K is 0. The chromosomes are constrained to be
between 1 and k0, i.e. if there are multiple k0 available, then they all can be scheduled at one time.
There is also a second part of the chromosome known as the tail. The tail of the chromosome
indicates a user precoding order. But the tail is left off since for the block diagonalization we do not
need the encoding order. So only the genetic algorithm is used to schedule users in the context of
zero–forcing beam

Nt1310 Unit 5 Application Of Research Paper In Mis
MULTIPLE INPUT MULTIPLE OUTPUT (MIMO)
In MIMO system there is multiple antennas is provided at the transmitter side as well as receiver
side. Using multiple antennas at the transmitter and the receiver side could able to increase spectral
efficiency, produces higher capacity and provides more data rates for wireless communication. In
MIMO system there is SU–MIMO that is called single user MIMO in which when there is data rates
need to be increased for single user then it is known as SU–MIMO, and if there is individual stream
is allocated to multiple users; then it is called multiuser MIMO (MU–MIMO).
In MIMO system, let's consider there is Mt transmitting antenna and Mr receive antennas where s=
[S1, S2......SM] t is the transmitted data vector, ... Show more content on Helpwriting.net ...
Functions of MIMO
The main function of MIMO system includes precoding, spatial multiplexing and diversity coding.
Precoding is the process of multi–stream beamforming which process at the transmitter. The main
advantage of multi stream beamforming is to increase the received signal input, by making signals
emitted from different antennas add up constructively and it is also able to mitigate the multipath
fading effect. Precoding requires channel state information at the transmitter. When there is multiple
antennas at the receiver, the transmit beamforming cannot simultaneously maximize the signal level
at all the receive antennas, and precoding with multiple stream is used. MIMO antenna
configuration is requires in spatial multiplexing. In spatial multiplexing the high rate signal is divide
into low rate signals and each individual stream is transmitted from different transmit antenna which
is having the same frequency channel. Spatial multiplexing is technique which is capable of
increasing channel capacity at higher signal to noise

Essay on Lab 2 Net360
Week 2 iLab Report
_____
DeVry University
NETW360: Wireless Technologies and Services
COMPUTE RF BEHAVIOR AND MIMO
Submitted to:
________
Date: ________
Compute RF Behavior
Calculate each of the five measurements in the project by performing every step in sequence. In
your own words, summarize what you have learned concerning RF behavior.
Calculations Step 4 (dBm of 1W): ____30 dBm = 1 W_____ Step 11 (max gain): ____9.538
dB________ Step 15 (.11g free space loss): ____0.00001 km______ Step 17 (.11a free space loss):
_____0 km___________ Step 19 (link budget): _____9.439__________
Summary of RF Behavior
In your own words, summarize what you have learned concerning RF behavior from your
calculations, readings, ... Show more content on Helpwriting.net ...
Advantages and Disadvantages of MIMO The version of MIMO using single input multiple output
has the advantage of being easy to implement, but the disadvantage is that the receiver requires
processing. This causes battery drain. The second version has two transmitter antennas. This gives
the advantage of redundancy coding and processing being moved to the transmitter. This decreases
the space the antenna needs and less processing is required to the receiver. This allows the device to
be smaller and has less battery drain. The last version is true MIMO. This increases the channel
throughput. This means that it can offer more data capacity. One disadvantage would be the cost and
added complexity.
MIMO Applications
Currently MIMO is being used Describe how MIMO is currently being used for routers, smart TVs
phones and wireless hotspots. 4G devices like the Kindle Fire HD use MIMO.
Future of MIMO Right now the future of MIMO isn't secure. Because devices won't be

interoperable, the cost to change over will be prohibitive. The standards based Wi–Fi gear like
routers would benefit from MIMO technology. This would include the Belkin, Linksys and Netgear
routers.
References
Cisco. (2008). Rf power values. Cisco. Retrieved from
http://www.cisco.com/en/US/tech/tk722/tk809/technologies_tech_note09186a00800e90fe.shtml.
Retrieved May 17, 2013
Wikipedia. (2013). MIMO. Retrieved from http://en.wikipedia.org/wiki/MIMO. Retrieved

Essay about What´s Cooperative Space-time Coding?
Literature Survey: Cooperative diversity for a simple three–terminal relay channel was first
introduced in [12]. Later, in [1], several improvements were made in capacity bounds and
cooperative schemes, such as decode–and–forward, were introduced. Modifications to amplify–and–
forward scheme were proposed in [13–16]. Based on these, more relaying schemes were introduced
in [17–24]. The performance and other characteristics of the aforementioned schemes in several
environments were studied in [17–27]. Extensions to a multi–terminal, multihop network were made
in [13–17], where a clustered model and ad hoc network architecture were studied and useful results
for transmit and receive diversity gains and relaying strategies were obtained. ... Show more content
on Helpwriting.net ...
Multiple–input multiple–output (MIMO) [2, 3, 30, 31] systems were introduced in order to enhance
the performance of the wireless communications systems to provide robustness, high data rates, and
reliability by overcoming the channel fading with the use of multiple antennas. A MIMO system
offers redundancy through the multiple independent channels, which are created between the
transmitting and the receiving antennas of the system. Using multiple–input multiple output
systems, significant improvements are made in the coverage ranges of the communication systems
and the data throughput without the need for additional transmission power or bandwidth expansion.
Cooperative diversity can also be used to increase the coverage area (e.g., cellular networks) as was
investigated in [2] For decode and forward if no MRC is deployed then the optimum location is
midway between the source and the destination, but if MRC is used then the optimum location is
towards the source as derived in [2]. A distributed relay assignment algorithm was also given in [2].
It also addresses the problem of relay–source assignment. The optimum locations of relay for
decode and forward and amplify and forward have also been proposed by the author.
Simon, Marvin K et al., in [3] presented a unified approach to evaluating the error rate performance
of digital communication system over fading channels. The classical relay channel was introduced
by Van der Meulen [4] models a three terminal

Limitations Of Wireless Communication
INTRODUCTION
There are lots of challenges occurs for reliable wireless communication which occurs due to
physical limitations of the wireless medium. There has been massive growth occurs in wireless
communication which is due to the techniques that improves spectral efficiency and mitigate various
channel impairments such as fading and interference. Moreover there is always demand for high
speed wireless internet and technologies which are capable of providing higher capacities and link
reliabilities. Multiple–input–multiple–output (MIMO) is based on communication system which is
able to fulfil these objectives. MIMO is an expansion of smart antennas systems. There were
traditional smart antennas which occupy multiple antennas at receiver, whereas In MIMO system
multiple antennas are engaged at both sides at transmitter as well as receiver side. The multiple
antennas at the transmitter and the receiver side provide a major advantage over traditional smart
antenna systems–in terms of capacity and diversity advantage. The multipath propagation by MIMO
system is a remarkably advantage over other antennas system. Moreover it is able to provide
independent fading channels between every pair of transmitter and receiver antennas.
The rapid improvement in communication system with high data rates and improved channel
capacity has pondered towards the study of both theoretical and practical in wireless communication
systems. Wireless communication system has made great effort to

Limitations Of Modulation In Isi
Due to the spectacular growth of the wireless services and demands during the last years, the need of
a modulation technique that could transmit high data rates at high bandwidth efficiency strongly
imposed. The problem of the inter–symbol interference (ISI) introduced by the frequency selectivity
of the channel became even more imperative once the desired transmission rates dramatically grew
up. Using adaptive equalization techniques at the receiver in order to combat the ISI effects could be
the solution, but there are practical difficulties in operating this equalization in real–time conditions
at several Mb/s with compact, low–cost hardware. ORTHOGONAL FREQUANCY DIVISION
MULTIPLEXING is a promising candidate that eliminates the need ... Show more content on
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Slow data rate (and long symbol duration) on each subchannel merely means that the effects of ISI
are severely reduced. This is in fact the basic idea that lies behind ORTHOGONAL FREQUANCY
DIVISION MULTIPLEXING . Transmitting the data among a large number of closely spaced
subcarriers accounts for the "frequency division multiplexing" part of the name. Unlike the classical
frequency division multiplexing technique, ORTHOGONAL FREQUANCY DIVISION
MULTIPLEXING will provide much higher bandwidth efficiency. This is due to the fact that in
ORTHOGONAL FREQUANCY DIVISION MULTIPLEXING the spectra of individual subcarriers
are allowed to overlap. In fact, the carriers are carefully chosen to be orthogonal one another. As it is
well known, the orthogonal signals do not interfere, and they can be separated at the receiver by
correlation techniques. The orthogonality of the subcarriers accounts for the first part of the
ORTHOGONAL FREQUANCY DIVISION MULTIPLEXING name. In a mobile radio
environment, the signal is carried by a large number of paths with different strength and delays.
Such multipath dispersion of the signal is commonly referred as "channel–induced ISI" and yields
the same kind of ISI distortion caused by an electronic filter [2]. In fact, the multipath dispersion
leads to an upper limitation of the transmission rate in order to avoid the frequency selectivity of the
channel or the need of a complex adaptive equalization in the receiver. In

Examination Of An Ofdm Mimo Framework Under Awgn Channel
Figure 3.20 BER examination of an OFDM–MIMO framework under AWGN channel. 3.3.3
Hardware Implementation Results Through the equipment co–simulation transform, the VHDL
coding of the framework is proficient. The created VHDL codes are transported in into the ISE
apparatus to make further framework check at the RTL level. Outline blend is performed with Xilinx
's XST and the entryway level netlist is gotten. After that, place and steering are performed. The
steering deferrals are back commented to the entryway level netlist for timing examination and
configuration advancement. At long last, a bitstream is created to program the objective FPGA
board. The proposed work is actualized on a Xilinx XUPV5–LX110T assessment stage and focused
to a XC5VLX110T–1FF1136 gadget. The CLBs are 160 x 54 exhibits. The objective gadget
incorporates 17,280 cuts with every containing four LUTs and four flip–flounders, 64 DSP48E cuts,
and 148 square RAMs with 36 Kb size. There are 32 worldwide clock systems and the load up clock
could accomplish 550 MHz clock speed, which completely fulfills the framework necessities. Table
3.1 and Table 3.2 abridge the region results concerning asset utilization, and the clock and timing
results for the transmitter and recipient, separately. The timing reports created from Xilinx Timing
Analyzer instrument shows no timing clash in the configuration. The greatest frequency is
sufficiently expansive to create 40 MHz clock and drive the entire framework.

Essay On Summing Circuit
a simple phase lock summing circuit which is very easy to implement.EGC can engage in the
reception of diversity with coherent modulation. As in EGC the diversity branches are combined
with equal gain but they have conjugate phase. Maximum ratio combining technique requires
summing circuits, weighting and co–phasing. Each of the signals from different branches are
weighted and co–phased with a gain factor which is proportional to the SNR before summing or
combining. The applied weighting to the diversity branches has to be adjusted according the SNR.
Techniques used in MIMO system In wireless communication system MIMO is used to provide
better performance as compared with others conventional systems. The multiple data stream is
provided in ... Show more content on Helpwriting.net ...
V–BLAST algorithm at the receiver is used to mitigate the interference between different streams
and try to generate the original data stream at the receiver. V–BLAST used optimal combining and
interference cancellation technique. The signal which is having the best SNR is retrieved at the
receiver. In the figure shown below which illustrates the good performance achieved at the receiver.
V–BLAST technique is referred as non–linear technique as it generates the best signals for
cancellation. Transmitter Processing Only In this technique of MIMO system, the signals processing
occurs at the transmitter only as the signal processing is restricted at the transmitter therefore it is
more beneficial for downlink scenario, because no signals is required at the mobile station. In case
of downlink system there is N number of antennas at the receiver with having N number of data
stream and each of it is multiplexed and output. There were three techniques used by the MIMO
system with antenna processing at the transmitter and having a simple receive structure which is the
transient zero forcing scheme, Filter bank method and transmit MMSE. All the interference has been
cut by the transmit zero forcing technique whereas the filter bank method is used to minimise the
signal to interference ratio in all sub–channels. Processing at Both the Receiver and

The Five Most Important Questions By Drucker
Introduction
The Five Most Important Questions by Drucker provides occupational leaders with an insightful
road map to gaining honest feedback. Along the way, the book takes numerous detours into further
analysis, thought and introspection (Drucker, 2008). These same questions apply to the Mind
Matters Online services (MiMO short form).The MiMo is an innovative idea of a group of
Psychiatrists, committed to bringing world–class mental health care within easy reach of a patient.
The analysis of the MiMo services provides a valuable input through which an organization can gain
a more accurate assessment of its effectiveness (MiMo, 2014).
The modern business management world has changed dramatically since, the book published 2008,
"The Five Most Important Questions..." by Drucker. To do the business or run an organization, first
ask the question "why we are doing business?" Best assessment is always depends upon asking the
right question, not providing the right answers. In these managerial decisions, the important and
difficult job is never to find right answer, it 's to find the right question to the organization (Drucker,
2012).
What is our Mission?
Each public segment establishment exits to make a distinguishing transformation in the lives of
persons and in the general public. Making this change is the mission–the organization's purpose and
a motive for being successful (Drucker, 2008, p. 11). The mission tells us, what you do and what
you expect form an organization.

IEEE 802.11n
Introduction: 802.11 are just digits for someone from outside wireless but for people interested in
wireless technologies they have a significant value. Institute for Electrical and Electronics Engineers
(IEEE) sets up certain standards for researching technologies in certain fields. 802 is such standard
which deals with Local area networks and Metropolitan area networks. 802.11 is the standard
dealing with implementation of Wireless–LAN. "IEEE 802.11 is a set of media access control
(MAC) and physical layer (PHY) specifications for implementing wireless local area network
(WLAN) computer communication in the 2.4, 3.6, 5 and 60 GHz frequency bands."[1] Whenever
they introduce a new standard, the old standard is incorporated into the latest version even though
many companies treat each revision as a new standard. IEEE 802.11n is a revolutionizing standard
which can achieve very high data rates with the introduction of MIMO technology in wireless
networks and modulation schemes like OFDM.[1] Theoretically, it can achieve a maximum data rate
of 600 MBPS which is nearly ten times more than its predecessor. It uses many efficient methods
such as MIMO technology, OFDM scheme and many multiplexing techniques such as spatial
multiplexing to bolster its quest for higher throughput. The fast growing mobile device usage also
inflames the development of wireless standards. The physical and medium access control layers in
wireless standards have a significant effect on the data

Taking a Look at MIMO Techniques
MIMO techniques are mostly used to accelerate system throughput over disruptive wireless
communication channels. It is well known fact that with the number of transmit antenna M and
number of receive antenna N, the capacity of MIMO systems increases linearly with a factor of MN.
The receiver decodes the received signal vectors into actual information, a narrow band flat fading
MIMO is designed as:
Y=Hx+n –––––– (1)
Where Y & x are received and transmitted vectors, H is channel matrix & n is the noise. During the
last decade, MIMO techniques in wireless industry have gained a huge interest in the study. MIMO
is treated as an extension of conventional smart antenna systems (SAS). In SAS, techniques of
beamforming are deployed and the optimal antenna weighting vector that determines antenna
radiation pattern is computed based on the optimal criterion such as maximum signal–to–
interference plus noise ratio (SINR), minimum mean square error (MMSE) [8]. The ability to
exploit and use the multipath propagation can be considered as one of the major advantages of
MIMO systems. In contrast to transmit beamforming schemes, channel state information (CSI) is
generally not required at the transmitter of MIMO systems. MIMO techniques for transmitting
systems can be majorly divided into two categories: spatial multiplexing and space–time coding
(spatial diversity techniques). In spatial multiplexing technique, it increases the data rate
(throughput) over a MIMO dedicated

4g Wireless Mobile Communication Networks
ABSTRACT
4G wireless mobile communication networks are been specified to support display, battery and
computational power etc. 4G wireless mobile communication networks should not focus on air
high speed wireless access system into different platforms.
The era of new wireless communication is evolving and it will soon penetrate into daily life and
change the way we live. The key concept is integrating the 4g capabilities with all of the existing
mobile technology. The purpose of this paper is to provide an overview of different aspects of 4g
technology which include its features, proposed architecture and key technological enabler. 4G
technology will encompass all system from various network public to private operator driven
broadband to personal area and adhoc Networks. 4g technology system will be fully IP based
wireless internet. With 4G technology a range new services and model will be available, this
services and model need to be further examine for interface with the design of 4g technology
system. 4G wireless mobile communication networks are been specified to support display, battery
and computational power etc. 4G wireless mobile communication networks should not focus on air
high speed wireless access system into different platforms. Based on different model, 4G wireless

Essay On Space Time Coding Techniques For MIMO-Ofdm
Space time coding techniques for MIMO–OFDM
OFDM provides the frequency selective channel which can able to divides the frequency band into
multiple sub channels and each sub channel carries a different stream of symbols. There is flat
frequency response throughput each sub channel when there is narrow bandwidth of each sub
channel. Therefore OFDM able to transform a frequency selective channel into set of multiple flat–
fading channels. Simultaneously when M transmit antennas used an OFDM transmitter, and N
receive antenna used OFDM front end then L flat fading MIMO channel is formed from MIMO
frequency selective channel with having dimensions equals to MxN. Earlier traditional space time
codes were not optimal for takeout the additional ... Show more content on Helpwriting.net ...
Receiver Processing Only
In this type of MIMO system the processing of signals occurs at the receiver only. Receiver
processing system is mostly beneficial in the uplink scenario as the signal processing is restricted to
the receiver and as at the mobile station no MIMO signal would be required. In case of uplink
scenario, there is a single data stream which is demultiplexed into the N number of substream, and
each substream is further modulated and passed it into N number of transmitters.
The power from each individual antenna is proportional to the 1/M. There is algorithm that is V–
BLAST algorithm which is used to perform at the receiver site. Taking into account, in the case of
uplink there is number of conventional receiver at the base station and they are receiving the signals
which are generated from N number of transmitters and therefore they must have considerable
interference between the data stream. V–BLAST algorithm at the receiver is used to mitigate the
interference between different streams and try to generate the original data stream at the receiver. V–
BLAST used optimal combining and interference cancellation technique. The signal which is having
the best SNR is retrieved at the receiver. In the figure shown below which illustrates the good
performance achieved at the receiver. V–BLAST technique is referred as non–linear technique as it
generates

The Antenna Structure X 4 Mimo 8x8 Mimo.
802.11n 802.11ac The antenna structure 4 x 4 MIMO 8x8 MIMO Channel width 20&40MHz
20,40,80+80 ,& 160MHz channel frequency 2.4 or 5GHz 5GHz single–stream data transfer rate
150Mbps(40MHz) 433Mbps(80MHz),867Mbps(160MHz) Multi–stream data transfer
polymerization rated 600Mbps(40MHz) 1.73Gbps(80MHz),347Gbps(160MHz) Modulation scheme
OFDM OFDM A comparison of the feature between 802.11n and 802.11ac 4.1 Work in the 5GHz
band 802.11ac only works in the 5GHz band, which means that any equipment want to work in
802.11ac must support 5GHz frequency band. Furthermore, 802.11ac's chipset also supports 2.4GHz
band, to supports 802.11a/b/g/n WLAN and other previous standard, to provide backward
compatibility. 4.1.1 Why 802.11ac is 5 GHz only? As we all know 5GHz frequency are poor
performance on long–distance transmission and through, we may want to ask why they remove
2.4GHz from 802.11ac. We now commonly used Wi–Fi basically work in 2.4G wireless frequency
band, using 802.11b / g protocol. But as more and more equipment is added to the 2.4GHz, the
channel became very crowded between 2.4 to 2.485GHz, because too many electronic devices are
working in this band (e.g. wireless keyboard, wireless mouse, Bluetooth and other). The crowded
channel will make the equipment to seize resources. For example, we are all connected to same
wireless router, everyone's computers and routers must communicate, if only one computer, it is
very simple, it can take 'dialogue' with router, because there

Advantages And Disadvantages Of Mimo Formatss
There is a number of different MIMO configurations or formats that can be used. These are termed
SISO, SIMO, MISO and MIMO. These different MIMO formats offer different advantages and
disadvantages – these can be balanced to provide the optimum solution for any given application.
The different MIMO formats – SISO, SIMO, MISO and MIMO require different numbers of
antennas as well as having different levels of complexity. Also dependent upon the format,
processing may be needed at one end of the link or the other – this can have an impact on any
decisions made.
SISO, SIMO, MISO, MIMO terminology
The different forms of antenna technology refer to single or multiple inputs and outputs. These are
related to the radio link. In this way the input is the transmitter as it transmits into the link or signal
path, and the output is the receiver. It is at the output of the wireless link.
therefore the different forms of single / multiple antenna ... Show more content on Helpwriting.net
...
The use of SIMO may be quite acceptable in many applications, but where the receiver is located in
a mobile device such as a cellphone handset, the levels of processing may be limited by size, cost
and battery drain.
There are two forms of SIMO that can be used:
Switched diversity SIMO: This form of SIMO looks for the strongest signal and switches to that
antenna.
Maximum ratio combining SIMO: This form of SIMO takes both signals and sums them to give the
a combination. In this way, the signals from both antennas contribute to the overall signal.
MIMO – MISO
MISO is also termed transmit diversity. In this case, the same data is transmitted redundantly from
the two transmitter antennas. The receiver is then able to receive the optimum signal which it can
then use to receive extract the required data.
MISO – Multiple Input Single

Microstrip Antennas : An Analysis
The Microstrip patch antenna has a dielectric substrate with a radiating patch and the feed lines are
etched on one side and a ground plane on the other side. The shape of the patch is not constrained
(could be square, rectangular, circular, triangular or elliptical) and it is generally made of conducting
material such as copper or gold. These antennas are mostly used at microwave frequencies, the
fringing fields between the patch edge and the ground plane cause the microstrip patch antennas to
radiate. An individual microstrip antenna consists of a patch of metal of various shapes on the
surface of a PCB, with a metal ground plane on the other side of the board. Most microstrip
antennas consist of multiple patches in a ... Show more content on Helpwriting.net ...
Further the consideration of space domain either with space diversity, smart antennas, and
nowadays, MIMO systems has also pushed the evolution of propagation modeling toward more
complex spatio–temporal considerations [1]. The MIMO antenna for wireless communications is
required to have a multiple bandwidth to cover the GSM, and ISM bands. On the other hand, it is
said that about 70% of the user demands and mobile flow for high–speed data services occur in
indoor environments [2–3]. In modern antenna design multiple–input multiple–output are employed
so that the multipath effects is taken as advantage to transmit multiple data stream. Designing
MIMO antennas have their own challenges such as mutual coupling because of electromagnetic
interaction between antenna elements [4–5].
2.1.2 APPLICATIONS OF MICROSTRIP PATCH ANTENNA Microstrip patch antenna can be
used for Mobile and satellite communication, Global Positioning System, Radio Frequency
Identification (RFID), Worldwide Interoperability for Microwave Access (WiMax), Radar,
Telemedicine, Rectenna and Medicinal. Mobile communication requires small, low profile and low–
cost antennas. Microstrip patch antennas are meet all requirements and various types of microstrip
antennas have been designed for use in mobile communication systems. In the case of satellite

4g Network And The Network Industry
1. Abstract
Although 4G network in some areas not yet fully universal, but the most recent 5G this topic has
fired up. 5G network as a next generation mobile communication network, its theoretical maximum
transfer speeds of up to tens of Gb per second, which is far more than the transmission rate of the
existing 4G network, the whole ultra–high–definition movie can be downloaded completed within
one second. 802.11ac technology are used in fifth generation network as a mainstay. It has also
become the focus of the network industry concerned. This report try to represent a full picture of
802.11ac technology.
table of content
1. Abstract 1
2. Introduction 2
2.1 Define 2
2.2 Context 3
2.3 Motivation 3
3. Literature review 4
4. 802.11ac key Technology 5
4.1 Work in the 5GHz band 6
4.1.1 Why 802.11ac is 5 GHz only? 6
4.2 MIMO 7
4.3 Challenge and issue in MIMO 7
4.3.1 Diversity and Multiplexing 7
4.3.2 Fading and interference 9
4.4 MU–MIMO 10
4.5 MAC virtual carrier sense technology 11
4.6 The large–scale MIMO technology 12
4.7 Multi–carrier technology filter group 14
4.8 Energy efficiency 16
4.9 Downward Compatible 16
5. Conclusion 16
6. Reference 17
7. Figure Reference 17
2. Introduction
2.1 Define

802.11ac is a new generation of network protocol. Because it runs in 5G Wi–Fi, this refers to the
fifth generation of Wi–Fi transmission technology, and runs 5Ghz radio wave bands. Here 's a
common problem 802.11ac and 5G Wi–Fi was a lot of confusion in the

Literature Review Cooperative Communication
CHAPTER 3 – COOPERATIVE COMMUNICATION
Background
We have introduced a new form of diversity for the concept of mobile communications system of
cooperation. Cooperation by mobile phone users for each user is assigned. Cooperation can be
considered as a new form of space diversity, antenna diversity in the transmission process, however,
and other complications, Intermobiles noisy channels, each phone has sent a separate message. (W.
Yu and T. Lan, 2007, pp. 2646–2660)
According to A. Goldsmith (2005), wireless communications technology is asking as functions of
mobile access. Since its inception, it has gone through several stages of development. Its wide range
of applications to meet growing demand. (A. Goldsmith, 2005) Multipath fading ... Show more
According to Cover and El Gamal (1979), this case create a virtual MIMO, nodes can collaborate
and share, to form a virtual antenna distribution MIMO antenna system is the simplest alternative
and more promising for the application. This is done through communication is called cooperation.
(Cover and El Gamal, 1979)
According to Cover and El Gamal (1979), a good performance in wireless communications
Multiple–Input Multiple–Output (MIMO) has drawn attention. The benefits of MIMO
communication has been widely recognized, as it offers a significant increase in performance and
range of data offline or additional bandwidth to transmit power. (Cover and El Gamal, 1979) By
increasing the speed and reduce discoloration. It offers a higher spectral efficiency, which means
more bits per hertz per second of bandwidth. The reliability of MIMO links in production, or in
other words, it reduces the changes in diversity.
Collaborative communication is a communication system or technology, allows users to send
messages to the destination type. (Quek, 2007, pp. 700–713)
According to Chandrasekaran (2005), the 4G mobile communications has arrived, introducing a
variety of services, use of different standards, different terminal services to deploy heterogeneous
networks. (Chandrasekaran, 2005) The method involves the use of all single–use devices, designed
to

Design And Implementation Of Mimo Ofdm
CAREER EPISODE –1 Mohd Saem (a) Introduction CE 1.1 CHRONOLOGY Project Title Design
and Implementation of MIMO OFDM Dates for the Project 2012 – 2013 Duration 1 year Name of
the Organization Electronics and Telecommunication Engineering Department Location New Rizvi
Educational Complex, Off Carter Road, Bandra West, Mumbai, Maharashtra 400050, India My Role
Project Demonstrator and project lead (b) Background CE 1.2 Rizvi college of engineering is a part
of the Rizvi Education Society, which is a public charitable trust. It was Established in the year 1950
under the Societies act and was listed under the requirements of Bombay Public act. This Society
promotes various fields of education like Hospitality, Hotel management, Science, Commerce, Arts,
Fashion Designing and Engineering. The location of college is ideal enviroments for students to
achieve their goals in life. CE 1.3 The main objective of this project was to successfully implement
transceiver that would help in developing 802.11 n modem. The architecture required the realization
of 802.16 (Wi–max) and LTE transceivers. It intended to study various alternatives for
implementation of the OFDM which resulted in reduced chip size. It included developing a
complete system of indigenously developed 802.11n modem which then offered maximum
throughput, robust and highly scalable WLAN connections/networks. CE 1.4 The principal role and

Error Performance Improvement Of A Multiplexed Mimo...
Error Performance improvement in Spatially Multiplexed MIMO Systems over Weibull–Gamma
Fading Channel
Keerti Tiwari and Davinder S. Saini
Department of Electronics and Communication Engineering
Jaypee University of Information Technology
Waknaghat, Solan, (H.P.) – 173234, India
E–mail– keerti.tiwari@mail.juit.ac.in, davinder.saini@juit.ac.in
Abstract– In multiple–input multiple–output (MIMO) systems, spatial demultiplexing at the receiver
is a motivational task. Thus, several detection techniques are investigated in existing literature.
There is a tradeoff between computational complexity and optimal performance in many detection
techniques. The ordered successive interference cancellation (OSIC) with minimum mean square
error (MMSE) is used to improve the error performance. However, maximum likelihood (ML)
detection gives optimal performance at the higher complexity level whereas MMSE–OSIC detection
is less complex. Therefore, MMSE–OSIC2 detection is suggested as a solution. In this paper, spatial
multiplexed (SM) MIMO systems are considered to evaluate error performance with different
detection techniques such as MMSE–OSIC, ML and MMSE–OSIC2 in a composite fading i.e.
Weibull–gamma (WG) fading environment. In WG distribution, Weibull and gamma distribution
represent multipath and shadowing effects respectively. It is shown by simulation results that the
MMSE–OSIC2 detection technique gives the improved symbol error performance (SER) which is
closely likely ML performance

Spectrum Is a Limied and Valuable Resource Essay
Spectrum is a limited and valuable resource. The escalating requirement for wireless communication
and broadband services has augmented the attempts to improve the designs for wireless systems.
These enhanced wireless systems offer substantial increase in data throughput and link range
without the requirement of any additional bandwidth. This led to the development of MIMO
Systems. In Multiple–Input Multiple–Output (MIMO) technology, multiple antennas are used at
both the transmitter and receiver to improve the functioning of the wireless communication system.
We accomplish this objective by exploiting the spatial domain of the transmission medium.
In this chapter, we describe the MIMO system model along with a brief discussion of its ... Show
more content on Helpwriting.net ...
The detector then chooses one of the BM possible transmitted symbol vectors based on the available
data. An optimal detector should return as x ̂ = x*.
3.3 MIMO System Model
The capacity of Single–Input Single–Output (SISO) wireless communication systems must be
increased to fulfill the ever–growing demands of efficient transmission rate. This can be done by
allocating additional bandwidth which is not always feasible due to the limited spectral resources
[Alamouti 1998]. Recent studies have proved that using spatial multiplexing MIMO systems can
boost the capacity of a wireless communication system significantly without the prerequisite of
extra–bandwidth.
Multipath propagation is an essential component of all wireless communication system.
Conventional radio systems rely on the strong primary signal and also make use of multipath
mitigation techniques to overcome multipath propagation and interference. Beam forming
technology or smart antenna technology is used for this purpose. A smart antenna is capable of
routing transmitted beam by scheming the phase of the signal at each element of the antenna array to
the receiver. Receiving diversity, this uses numerous antennas at the receiver side and merges all the
received signals to improve the signal reliability. These techniques are used to reduce the effect of
multipath propagation on the communication systems. MIMO makes use of multipath propagation
to get better throughput, range and reliability [Berrou 1996]. In

The Importance Of Multicarrier Techniques For A Single...
Chapter 1 Multicarrier techniques
This section deals with the importance of multicarrier techniques.
1.1 Multi carrier techniques
In a single carrier system, single fade causes the whole data stream and undergo distortion i.e
frequency selective fading. The Single carrier systems also suffer with heavy Inter Symbol
Interference . In telecommunication Inter Symbol Interference was a form of distortion of signal in
which one symbol interferes with the subsequent symbol. Thus it causes an unwanted phenomena as
the previous symbols have similar effect as noise thus making communication less reliable . ISI
occurs when the signal bandwidth is less than the coherence bandwidth or when the delay spread is
greater than symbol duration. To combat the problem multicarrier techniques have been proposed
for high data rate transmission. Multicarrier techniques divide the whole bandwidth into large
number of narrow band orthogonal subcarriers [1, 2]. Thus the signal bandwidth becomes very less
compared with coherence bandwidth ensuring no ISI in time domain and flat fading in frequency
domain. Multicarrier systems such as Orthogonal Frequency Division Multiplexing (OFDM) and
Multi Carrier Code Division Multiple Access (MC–CDMA) were considered to be the best
technologies for 4G wireless communication [1, 2]. Fig. explains the spectrum of multicarrier and
single carrier systems. In the single carrier system the information symbols are loaded into one of

Tone Injection Essay
This technique increases the constellation size so that each of the point in the original basic
constellation can be mapped into several equivalent points in the expanded constellation. Since
substituting a point in the basic constellation for a new point in the larger constellation is equivalent
to injecting a tone of the appropriate frequency and phase in the multicarrier signal, therefore, this
technique is called tone injection. The extra degrees of freedom, which is generated as each symbol
in the data block can be mapped into one of the several equivalent constellation points, can be
utilized for peak to average power ratio reduction. The distance between the original and extended
points is D. The receiver remains unaltered. D is ... Show more content on Helpwriting.net ...
Various works are available in literature mainly focusing on complexity reduction of optimization
problem. A gradient algorithm is proposed where the gradient of clipping noise mean square error is
calculated and optimization of signal to clipping noise ratio is done in place of peak to average
power ratio and order of complexity is O(N). A truncated IDFT algorithm is proposed where in place
of calculating entire IDFT values, it calculates on maximal IDFT element thus reducing complexity
of optimization process. The basic idea is to divide the group in two halves of N/2 and leave the half
with lesser energy and move in similar way till we reach the maximum energy element, however
this scheme may not always give correct maximal IDFT element, it also costs in lower peak to
average power ratio reduction. For designing the peak cancelling signal clipping noise is analysed
and several iterations of clipping and filtering are used till desired peak cancellation signal is
generated. References also proposed an adaptive–scaling algorithm and constant–scaling algorithm
for tone reservation. LSA–TR method with fast convergence is proposed which is based on least
square approximation and used to find the peak cancelling signal faster than clipping control TR
method. References used genetic algorithm to find the optimal PRC set, it also discussed an adaptive
amplitude clipping tone reservation algorithm (AAC–TR) to solve the optimization

Questions On Wireless Network And Security
Assignment–1
MN603
Subject Wireless Network and Security
Teacher Biplob Rakshit Ray
Name : Loveneet Singh Dhanjal
ID: MIT130071
Contents
1) Introduction 3
2) Massive MIMO architectures 3
a. V–BLAST 3
b. Array Architecture 4
3) Uses of massive MIMO to achieve convergence of wireless networks 5
a. Spatial multiplexing 6
b. Pre–coding 6
4) Existing Technologies 6
a. WiMAX 6
b. 3G 6
c. 4G LTE 7
5) Recently proposed techniques in the literature 7
5G 7
6) Relevant information 8
Massive MIMO advantages 8
Massive MIMO Challenges 8
7) Conclusion 8
References 9
1) Introduction
Massive MIMO is an antenna technology for wireless communications in which antennas are used
at both the ... Show more content on Helpwriting.net ...
On the other hand, if the multipath scattering is adequate, then the numerous sub–streams are all
scattered marginally in an unexpected way, since they start from diverse transmit receiving antennas
that are situated at different points. By utilizing modern sign preparing, these slight contrasts in
scrambling permit the sub streams to be distinguished and recouped. As a result, the unavoidable
multipath is abused to give an extremely valuable spatial parallelism that is utilized to significantly

enhance data transmission rates.
b. Array Architecture Massive MIMO demands uniquely large base–station arrays. Challenge was to
transporting signals between the source and the antenna. Any array architecture requires partitioning
the transceiver functions into those implemented close to the respective antennas and those
implemented at the main system controller. Transceiver can be subdivided into three parts
 Analog–connected array
 Digitally–connected array
 Digitally–connected array with distributed beam forming
3) Uses of massive MIMO to achieve convergence of wireless networks
Massive MIMO Wireless Network convergence means using one pipe to deliver all forms of
communication services like video, audio and data communication within network. Convenience
and flexibility is offered by using multiple communication modes in a single

Advantages And Disadvantages Of Network Densification
Network Optimization for future
Infrastructure Communication Introduction:
There has been a massive increase in mobile data traffic volume, which is always increasing every
year by two times. The main causes by which mobile data traffic is increasing are two: a rapid
increase in devices and data–hungry applications. In developing 5G, a lot of efforts have been made
in three different areas: spectrum expansion, spectrum efficiency and network densification. In
network densification, there made a large number of small cells. These small cells have small area
of coverage. Due to the deployment of small cells, there is an increase in complexity. Due to this , a
network operator has to face many problems:
Difficulty in managing and controlling
Intercell interference
Cost
To deal with above issues, a cloud based platform is ... Show more content on Helpwriting.net ...
Challenges for deployment of small cells: While deploying small cells, we face many challenges for
network operation and management and many more. If users may deploy small cells for their own
services, the network operator still need to deploy more small cells. This is a great challenge for
operator due to some reasons:
Network operator has a limited budget
On large scale deployment of small cells, a huge amount is require.
So the above issues need to be resolved in economical way. By deploying large number of small
cells, complexity increases, so a large number of employee is needed to install, monitor and
maintain the cells. Traffic may also changes frequently, so this is a huge problem for network
operator to manage all these problems in limited budget and resources. By increasing the number of
small cells, interference occurs between cells, which limit the gain of small cells. Intercell
interference coordination(ICIC) is introduced in 3rd Generation Partnership Project(3GPP) to
mitigate

MIMO Wireless Channel and How to Determine Its Capacity...
''If I have seen farther, it is by standing on the shoulders of giants.'' is very truly coated by Sir Isaac
Newton. Ideas gave way to idea. When Marconi invented wireless communication 100 years ago,
we had no idea that one day life will seem to be impossible without it. It has penetrated each and
every aspect of human life and has resulted into endless demands on bandwidth and spectrum. And
by standing on the shoulders of giants, Teletarand Foschinigave the technique of MIMO system
which would increase the spectral efficiency of the wireless system to its maximum compared to all
the current technologies. Multiple antennas are used for transmission and reception to increases the
capacity of the wireless channel.Capacity is expressed as the ... Show more content on
Helpwriting.net ...
SIMO
Fig1: Different antenna configurations in space–time systems.
Now we know that MIMO is an array, so we need to be some terms related to antenna array, which
is Array gain, the average increase in the signal–to–noise ratio (SNR) at the receiverthat arises from
the coherent combining effect of multiple antennas at the receiveror transmitter or both.If the
channel is known to the multiple antenna transmitter,
The transmitter will weigh the transmission with weights, depending on the channelcoefficients, so
that there is coherent combining at the single antenna receiver.The array gain in this case is called
transmitter array gain. And vice versa for SIMO case, which will be known as receiver Array Gain.
Basically, multiple antenna systems require perfectchannel knowledge either at the transmitter or
receiver or both to achieve thisarray gain. Next important term is Diversity Gain. Multipath fading is
a significant problem in communications. In a fading channel,signals experience fades.When the
signalpower drops significantly, the channel is said to be in a fade. This gives rise tohigh bit error
rates (BER).This involvesproviding replicas of the transmitted signal over time, frequency, or space.
Thereare three types of diversity schemes in wireless communications:
I .Temporal diversity: In this case replicas of the transmitted signal are provided across time by a
combination of channel coding and time interleaving strategies.

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