This document investigates the bit error rate (BER) performance of MIMO systems with different numbers of transmitting antennas. It begins with an introduction to fading in wireless channels and how MIMO can be used to combat it using multiple antennas. It then describes the Alamouti space-time coding scheme and how maximum likelihood decoding works. Simulations are presented comparing the BER of a BPSK modulated MIMO system with 2, 3, and 4 transmitting antennas under Rayleigh fading. The results show that increasing the number of transmitting antennas decreases the BER, with 4 antennas performing best due to a larger transmission matrix and more data being transmitted.
International Journal of Engineering Research and Applications (IJERA) aims to cover the latest outstanding developments in the field of all Engineering Technologies & science.
International Journal of Engineering Research and Applications (IJERA) is a team of researchers not publication services or private publications running the journals for monetary benefits, we are association of scientists and academia who focus only on supporting authors who want to publish their work. The articles published in our journal can be accessed online, all the articles will be archived for real time access.
Our journal system primarily aims to bring out the research talent and the works done by sciaentists, academia, engineers, practitioners, scholars, post graduate students of engineering and science. This journal aims to cover the scientific research in a broader sense and not publishing a niche area of research facilitating researchers from various verticals to publish their papers. It is also aimed to provide a platform for the researchers to publish in a shorter of time, enabling them to continue further All articles published are freely available to scientific researchers in the Government agencies,educators and the general public. We are taking serious efforts to promote our journal across the globe in various ways, we are sure that our journal will act as a scientific platform for all researchers to publish their works online.
This presentation illustrates the experience gained by me during a RF circuit design course. The course requirements included designing, fabricating and simulating various couplers, an amplifier, a low noise amplifier and an oscillator. Operating frequency was centered around 2.4 GHz.
International Journal of Engineering Research and Applications (IJERA) aims to cover the latest outstanding developments in the field of all Engineering Technologies & science.
International Journal of Engineering Research and Applications (IJERA) is a team of researchers not publication services or private publications running the journals for monetary benefits, we are association of scientists and academia who focus only on supporting authors who want to publish their work. The articles published in our journal can be accessed online, all the articles will be archived for real time access.
Our journal system primarily aims to bring out the research talent and the works done by sciaentists, academia, engineers, practitioners, scholars, post graduate students of engineering and science. This journal aims to cover the scientific research in a broader sense and not publishing a niche area of research facilitating researchers from various verticals to publish their papers. It is also aimed to provide a platform for the researchers to publish in a shorter of time, enabling them to continue further All articles published are freely available to scientific researchers in the Government agencies,educators and the general public. We are taking serious efforts to promote our journal across the globe in various ways, we are sure that our journal will act as a scientific platform for all researchers to publish their works online.
This presentation illustrates the experience gained by me during a RF circuit design course. The course requirements included designing, fabricating and simulating various couplers, an amplifier, a low noise amplifier and an oscillator. Operating frequency was centered around 2.4 GHz.
Optimization of Cmos 0.18 µM Low Noise Amplifier Using Nsga-Ii for UWB Applic...VLSICS Design
A design and optimization of 3-5 GHz single ended Radio Frequency (RF) Low Noise Amplifier (LNA) for
ultra-wide-band (UWB) applications using standard UMC 0.18 μm CMOS technology is reported.
Designing of RF circuit components is a challenging job, since even after performing lengthy calculations
and finding parameter values it is less guarantee that the design performs as expected. In view of this the
optimization tool; Elitist Non-Dominated Sorting Genetic Algorithm (NSGA-II); has been employed to get
the optimized starting values of components in the proposed LNA design. The obtained NSGA-II
parameters were simulated using Cadence Spectre- RF simulator. The designed Low Noise Amplifier
achieves a power gain of 22 dB and a minimum Noise Figure of 3 dB is achieved. It dissipates 12.5 mW of
power out of 1.8 V supply.
Bandwidth-Performance Tradeoffs for a Transmission with Concurrent Signalscsandit
We consider a bandwidth-efficient transmission sche
me, where two signals are sent
concurrently. The BER and the achievable minimum di
stances for the signals’ constellations at
the receivers are derived as functions of the signa
ls’ energies and their input probability
distributions. Finally, trade-offs between bandwidt
h, signals’ energies and achievable
performances are discussed.
For ease of analog or digital information transmission and reception, modulation is the foremost important technique. In the present project, we’ll discuss about different modulation scheme in digital mode done by operating a switch/ key by the digital data. As we know, by modifying basic three parameters of the carrier signal, three basic modulation schemes can be obtained; generation and detection of these three modulations are discussed and compared with respect to probability of error or bit error rate (BER).
introduce the basic modulation tech (PSK, FSK, QAM etc)
and comparison between them.
ref : Communication System (4ed, Haykin)
this ppt is for my seminar
DESIGN AND NOISE OPTIMIZATION OF RF LOW NOISE AMPLIFIER FOR IEEE STANDARD 802...VLSICS Design
Low noise amplifier is the front end block of radio-frequency receiver system. Its design required various characteristics such as power gain, noise figure, insertion losses and power consumption. In this paper we have proposed a single stage low noise amplifier design with high gain and low noise using inductive source degeneration topology for frequency range of 3 GHz to 7 GHz and also use the active biasing devices. A range of devices like inductors and capacitors are used to achieve 50 Ω input impedance with a low noise factor. The design process is simulated process is using Advance Design System (ADS) and implemented in TSMC 0.18 µm CMOS technology. A single stage low noise amplifier has a measured forward gain 25.4 dB and noise figure 2.2 dB at frequency 5.0 GHz.
Performance Comparison of RF CMOS Low Noise Amplifiers in 0.18-µm technology ...VLSICS Design
This paper presents the design theory of conventional single-ended LNA and differential LNA based on CMOS technology. The design concepts give an useful indication to the design trade-offs associated with NF, gain and impedance matching. Four LNA’s have been designed using technological design rules of TSMC 0.18-µm CMOS technology and this work mainly proposed for IEEE 802.11a applications. With 1.8V supply voltage, the proposed LNA’s achieve a gain higher than 19dB, a noise figure less than 4dB and impedance matching less than -10dB at 5GHz frequency. The goal of this paper is to highlight the efficient LNA architecture for achieving simultaneous gain, noise and input matching at low supply voltage. The performance of all LNA’s are analysed and compared using Agilent’s Advanced Design System Electronic Design Automation tools.
Optimization of Cmos 0.18 µM Low Noise Amplifier Using Nsga-Ii for UWB Applic...VLSICS Design
A design and optimization of 3-5 GHz single ended Radio Frequency (RF) Low Noise Amplifier (LNA) for
ultra-wide-band (UWB) applications using standard UMC 0.18 μm CMOS technology is reported.
Designing of RF circuit components is a challenging job, since even after performing lengthy calculations
and finding parameter values it is less guarantee that the design performs as expected. In view of this the
optimization tool; Elitist Non-Dominated Sorting Genetic Algorithm (NSGA-II); has been employed to get
the optimized starting values of components in the proposed LNA design. The obtained NSGA-II
parameters were simulated using Cadence Spectre- RF simulator. The designed Low Noise Amplifier
achieves a power gain of 22 dB and a minimum Noise Figure of 3 dB is achieved. It dissipates 12.5 mW of
power out of 1.8 V supply.
Bandwidth-Performance Tradeoffs for a Transmission with Concurrent Signalscsandit
We consider a bandwidth-efficient transmission sche
me, where two signals are sent
concurrently. The BER and the achievable minimum di
stances for the signals’ constellations at
the receivers are derived as functions of the signa
ls’ energies and their input probability
distributions. Finally, trade-offs between bandwidt
h, signals’ energies and achievable
performances are discussed.
For ease of analog or digital information transmission and reception, modulation is the foremost important technique. In the present project, we’ll discuss about different modulation scheme in digital mode done by operating a switch/ key by the digital data. As we know, by modifying basic three parameters of the carrier signal, three basic modulation schemes can be obtained; generation and detection of these three modulations are discussed and compared with respect to probability of error or bit error rate (BER).
introduce the basic modulation tech (PSK, FSK, QAM etc)
and comparison between them.
ref : Communication System (4ed, Haykin)
this ppt is for my seminar
DESIGN AND NOISE OPTIMIZATION OF RF LOW NOISE AMPLIFIER FOR IEEE STANDARD 802...VLSICS Design
Low noise amplifier is the front end block of radio-frequency receiver system. Its design required various characteristics such as power gain, noise figure, insertion losses and power consumption. In this paper we have proposed a single stage low noise amplifier design with high gain and low noise using inductive source degeneration topology for frequency range of 3 GHz to 7 GHz and also use the active biasing devices. A range of devices like inductors and capacitors are used to achieve 50 Ω input impedance with a low noise factor. The design process is simulated process is using Advance Design System (ADS) and implemented in TSMC 0.18 µm CMOS technology. A single stage low noise amplifier has a measured forward gain 25.4 dB and noise figure 2.2 dB at frequency 5.0 GHz.
Performance Comparison of RF CMOS Low Noise Amplifiers in 0.18-µm technology ...VLSICS Design
This paper presents the design theory of conventional single-ended LNA and differential LNA based on CMOS technology. The design concepts give an useful indication to the design trade-offs associated with NF, gain and impedance matching. Four LNA’s have been designed using technological design rules of TSMC 0.18-µm CMOS technology and this work mainly proposed for IEEE 802.11a applications. With 1.8V supply voltage, the proposed LNA’s achieve a gain higher than 19dB, a noise figure less than 4dB and impedance matching less than -10dB at 5GHz frequency. The goal of this paper is to highlight the efficient LNA architecture for achieving simultaneous gain, noise and input matching at low supply voltage. The performance of all LNA’s are analysed and compared using Agilent’s Advanced Design System Electronic Design Automation tools.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
PERFORMANCE EVALUATION OF BER FOR AWGN, AWGN MULTIPATH AND RAYLEIGH FADING CH...IJEEE
The objectives of this paper are to study, analyze and evaluate the performance of BER (Bit Error Rate) in mobile multipath fading propagation channel. The parameters which are considered for the performance evaluation are AWGN, AWGN Multipath, Rayleigh fading channel and Hadamard code generator.
Intermodulation Distortion Cancellation by Feedforward Linearization of Power...IJERA Editor
Intermodulation distortion has been a major source of linearity when a power amplifier is used for multichannel
systems in wireless communication. Since, distortion products appear close to original input carriers they need to
be cancelled out so that information reaches unaltered and distortion-less at the destination. In this paper,
feedforward technique has been selected to obtain maximum intermodulation distortion reduction. To
demonstrate linearity improvement, along with IMD measurement, carrier to IMD power ratio (C/I) and
intercept points are also evaluated. Later on, the feedforward power amplifier is tested by sweeping input power
within a specified range and graphs for IMD and intercept points are derived. The results show that the
feedforward linearized power amplifier achieves best results when operated at input power levels around and
above -12 dBm.
Adaptive transmit diversity selection (atds) based on stbc and sfbc fir 2 x1 ...eSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
Analysis of Space Time Codes Using Modulation TechniquesIOSR Journals
Abstract: In this Paper, Analysis of channel codes for improving the data rate and reliability of communication over fading channels using multiple transmit antennas has been considered. The codes, namely ’Space Time Codes’ render full diversity and amend coding gain. Performance criteria for designing such codes, under this assumption that the fading is slow and nonselective frequency, is also analysed. Under this research, Study of Frame Error Rate(FER) and outage capacity is compared for different no. Of transmit and receive antennas as well as for different modulation techniques. According to theoretical results FER decreases with increasing SNR and No. Of receiving antennas. Numerical and practical result shows that FER decreases with increasing SNR and no. Of receiving antennas. Keywords: Space time Block Codes ,Space time trellis Codes,Frame Error Rate(FER),Outage capacity,Pairwise Error Probability
On limits of Wireless Communications in a Fading Environment: a General Param...ijeei-iaes
The reliable services along with high throughput can be achieved by using wireless communication systems. These systems also provides a wide coverage because of their features, no doubt MIMO Communication System [1] is one among them. Features provided by these systems ensure the improved system coverage and increased data transmission rate by considering multiple numbers of transmitter and receiver antennas. In this article, the concept of equalization has been considered and finally the performance of the MIMO Systems in Rician flat fading [5] channel is compared with the Rayleigh flat fading channel. It has also been observed that the performance of these Systems in Rician Flat Fading Channel is the best as compare to the Rayleigh Flat Fading Channel [10]. It has been concluded that the successive interference methods provide better performance as compare to others, but their complexity is high. Simulation results shows that ML provides the better performance in comparison to other equalizers but Sphere decoder provides the best performance.
A Threshold Enhancement Technique for Chaotic On-Off Keying SchemeCSCJournals
In this paper, an improvement for Chaotic ON-OFF (COOK) Keying scheme is proposed. The scheme enhances Bit Error Rate (BER) performance of standard COOK by keeping the signal elements at fixed distance from the threshold irrespective of noise power. Each transmitted chaotic segment is added to its flipped version before transmission. This reduces the effect of noise contribution at correlator of the receiver. The proposed system is tested in Additive White Gaussian Noise (AWGN) channel and compared with the standard COOK under different Eb/No levels. A theoretical estimate of BER is derived and compared with the simulation results. Effect of spreading factor increment in the proposed system is studied. Results show that the proposed scheme has a considerable advantage over the standard COOK at similar average bit energy and with higher values of spreading factors.
At this present scenario, the demand of the system capacity is very high in wireless network. MIMO
technology is used from the last decade to provide this requirement for wireless network antenna
technology. MIMO channels are mostly used for advanced antenna array technology. But it is most
important to control the error rate with enhanced system capacity in MIMO for present-day progressive
wireless communication. This paper explores the frame error rate with respect to different path gain of
MIMO channel. This work has been done in different fading scenario and produces a comparative analysis
of MIMO on the basis of those fading models in various conditions. Here, it is to be considered that
modulation technique as QPSK to observe these comparative evaluations for different Doppler frequencies.
From the comparative analysis, minimum amount of frame error rate is viewed for Rician distribution at
LOS path Doppler shift of 0 Hz. At last, this work is concluded with a comparative bit error rate study on
the basis of singular parameters at different SNR levels to produce the system performance for uncoded
QPSK modulation.
Designing and Performance Evaluation of 64 QAM OFDM SystemIOSR Journals
Abstract (11Bold) : — In this report, the performance analysis of 64 QAM-OFDM wireless communication
systems affected by AWGN in terms of Symbol Error Rate and Throughput is addressed. 64 QAM (64 ary
Quadrature Amplitude Modulation) is the one of the effective digital modulation technique as it is more power
efficient for larger values of M(64). The MATLAB script based model of the 64 QAM-OFDM system with
normal AWGN channel and Rayleigh fading channel has been made for study error performance and
throughput under different channel conditions. This simulated model maximizes the system throughput in the
presence of narrowband interference, while guaranteeing a SER below a predefined threshold. The SER
calculation is accomplished by means of modelling the decision variable at the receiver as a particular case of
quadratic form D in complex Gaussian random variables. Lastly comparative study of SER performance of 64
QAM-OFDM simulated & 64 QAM-OFDM theoretical under AWGN channel has been given. Also
performance of the system is given in terms of throughput (received bits/ofm symbol) is given in a plot for
different SNR. Keywords (11Bold) –64 QAM, BPSK, OFDM, PDF, SNR.
Designing and Performance Evaluation of 64 QAM OFDM SystemIOSR Journals
In this report, the performance analysis of 64 QAM-OFDM wireless communication
systems affected by AWGN in terms of Symbol Error Rate and Throughput is addressed. 64 QAM (64 ary
Quadrature Amplitude Modulation) is the one of the effective digital modulation technique as it is more power
efficient for larger values of M(64). The MATLAB script based model of the 64 QAM-OFDM system with
normal AWGN channel and Rayleigh fading channel has been made for study error performance and
throughput under different channel conditions. This simulated model maximizes the system throughput in the
presence of narrowband interference, while guaranteeing a SER below a predefined threshold. The SER
calculation is accomplished by means of modelling the decision variable at the receiver as a particular case of
quadratic form D in complex Gaussian random variables. Lastly comparative study of SER performance of 64
QAM-OFDM simulated & 64 QAM-OFDM theoretical under AWGN channel has been given. Also
performance of the system is given in terms of throughput (received bits/ofm symbol) is given in a plot for
different SNR
Computer-Based Analysis of The Performance of Different Modulation Techniques...theijes
The wideband code division multiple access (WCDMA) mobilewireless networks is among the lot of experiences digital communication has had for its tremendous growth. WCDMAnetworks are meant to provide a diverse amount/range of multimedia services tomobile users with assured quality of service (QoS). To achieve this, our report is dwelling mainly on the analysis of the performanceof Phase Shift Keying modulation(M-PSK)and MAry Pulse Amplitude Modulation (PAM)in WCDMA with different modulation channels,by comparing channel element like Bit Error Ratein RAYLEIGH fading and AWGN Channels using Matlab/Simulink. This research analysis will assist/enable us determine which modulation technique is performance effective in WCDMAsystem via any of these channelsat higher run time and M-Ary number.
PERFORMANCE ANALYSIS OF 2*2 MIMO CHANNEL USING ZF EQUALIZER VaishaliVaishali14
The following content are present related to performance analysis of 2*2 mimo channel equalization technique
OBJECTIVE
INTRODUCTION
MIMO
2X2 MIMO CHANNEL
2X2 MIMO CHANNEL WITH ZF EQUALIZER
BER OF 2x2 MIMO CHANNEL WITH ZF EQUALIZER
PROGRAM AND SIMULATION OUTPUTS
RESULTS AND DISCUSSION
CONCLUSION
REFERENCES
Improving the error performance of offset pulse position modulation using Re...IJECEIAES
An innovative performance study of an offset pulse-position modulation (OPPM) scheme is presented in this work with Reed–Solomon (RS) and low-density parity-checking (LDPC). The main aim is to resolve the errors of OPPM three using an RS or LDPC as a sporadic set of forward error correction (FEC). In this regard, the separate FEC has been utilized with coding that is based on multi-level, and waveform shaping based on the trellis. To systematically conduct this research, the greatest transmission efficiency that associated with the optimum RS code rates at different fiber normalization bandwidths is evaluated. Furthermore, the transmission efficiencies, channel extension, as well as the required number of photons per pulse of OPPM before and after the integration with RS or LDPC are compared. The results indicate an enhancement of mitigating the system's bit error rate and delivering more error-free data to the receiver in the occasion of applying the optimal settings of the RS or LDPC.
BER Comparison of AWGN channels for different types of Digital modulation
Ac35162165
1. Shakey Garg, Int. Journal of Engineering Research and Application www.ijera.com
Vol. 3, Issue 5, Sep-Oct 2013, pp.162-165
www.ijera.com 162 | P a g e
Bit Error Rate Investigations on Mimo System With Different
Number of Transmitting Antennas
Shakey Garg
Yadavindra College of Engineering and Technology, Talwandi Sabo(Bathinda)
Abstract: Fading is a common problem in wireless communication systems. MIMO has emerged as a
technology that can be used to combat this problem using multiple antennas at transmitter and receiver. In this
paper bit error performance of MIMO system with different transmitting antennas has been investigated.
Key Words: Alamouti Scheme, Bit Error Rate, Fading, MIMO, Rayleigh Fading.
I. INTRODUCTION
As wireless channel is random and
unpredictable by its nature, and in general channel
error rates are poorer over a wireless channel than
over a wired channel. A major problem in the
wireless channel is reception of multi-path signal.
This multiplicity of paths leads to a phenomenon
known as multi-path fading [4]. These multiple
paths are caused by the presence of objects in the
physical environment that, through the mechanisms
of propagation, alter the path of radiated energy.
This result in rapid fluctuation in amplitude, phase
or multi-path delays of a transmitted signal over a
small period of time or travel distance [18]. In some
cases, the multiple signals add destructively at the
receiver, creating points in space where the
composite received signal is greatly attenuated
[1].Also the relative motion between the
communicating devices induce Doppler shift on
multi-path components and results in fading of the
signal.
To combat the effect of fading, an
emerging technology called multiple input and
multiple output (MIMO) has appeared. In MIMO
systems, multiple antennas at both transmitter &
receiver and diversity techniques can be used to
reduce multi-path fading and interference. Diversity
can be achieved by providing a copy of the
transmitted signal over frequency, time and space.
In 1991, Alamouti proposed a transmit diversity
technique using two transmit antennas, whose key
advantage was the employment of low complexity
use of multiple symbols. The decoding algorithm
proposed in this can be generalized to an arbitrary
number of receive antennas using MRC, equal gain
combining (EGC) or successive combining (SC).
The new scheme does not require any bandwidth
expansion any feedback from the receiver to the
transmitter and its computation complexity is
similar to MRRC. This paper presents bit error
investigations on MIMO system for different
Number of transmitter antennas.
II. ALAMOUTI SCHEME
Alamouti scheme, a simple transmit
diversity scheme suitable for two transmit antennas.
Before coding the base band signal would be
modulated at each antenna using an M-PSK
modulated scheme. Then the modulated signal has
been encoded by space time block code technique. It
should be assumed here the transmitter does not
have channel knowledge but the receiver full
knowledge about the channel. It would first see, two
transmit antenna and one receive scheme then two
transmit and two receive scheme.
The system model for the Alamouti Space-
Time scheme has been shown in Fig 1. The model
consists of two transmit antennas 1XT and 2XT
with the associated channel gains 1h and 2h
respectively which may be modeled as Rayleigh
fading channel. At the transmitter, the information
bits have been first modulated using an M-ary
modulation scheme.
Fig 1: Alamouti Space-Time Coding Scheme
using Maximum likelihood decoding
The encoder then takes a block of two
modulated symbols 1s and 2s in each encoding
operation and gives it to the transmit antennas
according to the code matrix given in equation (1).
1 2
2 1
s s
S
s s
(1)
Where, the first column represents the first
transmission period and the second column the
second transmission period. The first row
corresponds to the symbols transmitted from first
RESEARCH ARTICLE OPEN ACCESS
2. Shakey Garg, Int. Journal of Engineering Research and Application www.ijera.com
Vol. 3, Issue 5, Sep-Oct 2013, pp.162-165
www.ijera.com 163 | P a g e
antenna and second row corresponds to the symbols
transmitted. At the receiver the faded signals are
corrupted by Additive White Gaussian Noise
(AWGN) process. Where 1r correspond to the
symbols 1s and 2s sent from antennas 1 and 2
respectively at time 1t t and 2r corresponds to
the symbols 2s
and 1s
sent from antennas 1
and 2 respectively at time 1t t T . 1n and 2n
are the sample functions of an additive white
Gaussian noise process. 1r and 2r can be given
as
1 1 1 2 2 1r h s h s n
2 1 2 2 1 2r h s h s n
(2)
This can be written in matrix form as:
r Sh n (3)
III. MAXIMUM LIKELIHOOD
DECODING
While the encoder may utilize any
modulation scheme, the decoder consists of first
estimating the channel gains for reliable decoding
and a combiner that utilizes the estimated gains and
the received data sequences to correctly decode the
symbols. It has been assumed that the receiver is
able to perfectly estimate the channel gains 1h
and 2h [11]. The combiner combines these
estimated channel gains 1h , 2h and the received
vectors 1r and 2r to generate
~
1s and
~
2s as
~
2 2
1 1 1 2 2 1 2 1 1 1 2 2
~
2 2
2 2 1 1 2 1 2 2 1 2 2 1
( )
( )
s h r h r s h n h n
s h r h r s h n h n
(4)
The ML detector then calculates the
decision metric for all combinations of 1s and 2s
and chooses the one which minimizes it. The
decision metric has been given in equation (5).
22
1 1 1 2 2 2 1 2 2 1r h s h s r h s h s
(5)
Conjugating the signal 2r in (2) that has
been received in the second symbol period, the
received signal may be written equivalently as
~
1 1 1 2 2 1r h s h s n
~
2 1 2 2 1 2r h s h s n
(6)
over all possible values of 1s and 2s . Expanding
this and deleting terms that has independent of the
code words, the above minimization reduces to
separately minimizing
2 22 2
1 1 2 2 1 1 2 11rh r h s s
(7)
for detecting 1s and
2 22 2
1 2 2 1 2 1 2 21rh r h s s
(8)
for decoding 2s .
IV. SIMULATION AND DISCUSSION
First a random bit stream has been
generated. Then signal power level can be defined
and using the encoding scheme the symbols are
generated that are supposed to be transmitted. The
encoded symbols can be transmitted through
multipath faded channel. Here channel can be
assumed to be flat faded and channel distortion can
be assumed to be multipath. The channel can be
generated as CN (m,N) where CN stands for
circularly symmetric Gaussian random variable, m
is mean and N is variance. The symbols have been
estimated at the receiver using ML detection. Then
AWGN can be added in the system which has been
generated using normally distributed and generated
as N (0, 1), where N stands for normally distributed
RV with 0 mean and variance 1. The system
performance has then checked at different values of
SNR and for different modulation schemes.10,000
symbols have been generated for each simulation
and then the BER Vs SNR curves are plotted.
5
Fig 2. BER performance of BPSK modulation
scheme for different antennas under Rayleigh
fading environment
Fig 2 shows the BER performance of BPSK
modulation scheme for different antennas under
Rayleigh fading environment. Table 1 shows the
BER Performance of BPSK modulation scheme for
2 transmitting and 1 receiving antenna under
Rayleigh fading environment.
3. Shakey Garg, Int. Journal of Engineering Research and Application www.ijera.com
Vol. 3, Issue 5, Sep-Oct 2013, pp.162-165
www.ijera.com 164 | P a g e
Table 1: BER performance of BPSK modulation
scheme for 2 transmitting and 1 receiving
antenna under Rayleigh fading environment
Signal to Noise Ratio
(SNR)
Bit Error Rate
(BER)
0 0.219
2 0.190
4 0.099
6 0.075
8 0.055
10 0.018
12 0.009
14 0.005
16 0.002
18 0.0007
20 0.00022
Table 2 shows the BER performance of BPSK
modulation scheme for 2 transmitting and 1
receiving antenna under Rayleigh fading
environment. By comparing figures 2 and 3, it is
clear that with increasing transmitting antennas,
BER rapidly decreases as compare to BPSK
modulation scheme and tables 1 and 2, it is clear
that BER decreases with increasing SNR.
Table 2: BER performance of BPSK modulation
scheme for 3 transmitting and 1 receiving
antenna under Rayleigh fading environment
Signal to Noise Ratio
(SNR)
Bit Error Rate
(BER)
0 0.211
2 0.130
4 0.075
6 0.055
8 0.0115
10 0.0050
12 0.0013
14 0.0012
16 0.0010
18 0.00005
20 0.00001
Table 3 shows BER performance of BPSK
modulation scheme for 4 transmitting and 1
receiving antenna under Rayleigh fading
environment. From figure 5.1 and table 5.3, it can be
concluded that with increasing SNR, BER decreases
when 4 transmitting and 1 receiving antennas of
STBC using Alamouti scheme but it has lower BER
as compared to using 2 transmitting and 3
transmitting antennas.
Table 3: BER performance of BPSK modulation
scheme for 4 transmitting and 1 receiving
antenna under Rayleigh fading environment
Signal to Noise Ratio
(SNR)
Bit Error Rate
(BER)
0 0.200
2 0.119
4 0.073
6 0.040
8 0.008
10 0.002
12 0.0007
14 0.00018
16 0.00002
18 0.00009
20 0.00004
V. CONCLUSION
From results, it has been concluded that
Space-time block codes with larger number of
transmit antennas always give better
performance than space-time block codes with
lower number of transmit antennas due to lager
number of transmit antennas that has larger
transmission matrices which means transmitting
more data. This would give the receiver the
ability to recover the transmitted data.
REFERENCES
[1] Costa Nelson, Haykin Simon (1978)
Multiple-Input, Multiple-Output Channel
Models: Theory and Practice. New York:
John Wiley & Sons.
[2] Rappaport Theodore S. (2) (2008) Wireless
Communications. Prentice-Hall, Inc.
[3] Jakes W. C. Mobile Communications (1974)
New York: John Wiley & Sons.
[4] Winters J. H. (1998) Smart antennas for
wireless system. IEEE Personal
Communication Magazine, 5: 23–27.
[5] Godara L. C. (1997) Applications of antenna
arrays to mobile communications, part I:
performance improvements, feasibility, and
system considerations. IEEE, 85: 1031–
1060.
[6] Foschini G. J.(1996) Layered space-time
architecture for wireless communications in
a fading environment when using multiple
antennas. Bell Labs Technology J., 1: 41–
59.
[7] Telatar I. E. (1999) Capacity of multi-
antenna Gaussian channels. Eur. Trans.
Telecomm., 10: 585–595.
[8] Wittneben A. (1991) Base station
modulation diversity for digital
SIMULCAST: 848–853.
[9] Wittneben A. (1993) A new bandwidth
efficient transmit antenna modulation
diversity scheme for linear digital
4. Shakey Garg, Int. Journal of Engineering Research and Application www.ijera.com
Vol. 3, Issue 5, Sep-Oct 2013, pp.162-165
www.ijera.com 165 | P a g e
modulation. IEEE International Conf.
Communications: 1630–1634.
[10] Seshadri N. and Winters J. H. (1993) Two
signaling schemes for improving the error
performance of FDD transmission systems
using transmitter antenna diversity. IEEE
Vehicular Technology Conf. (VTC 43rd) :
508–511.
[11] Alamouti. S. M. (1998) A simple transmit
diversity technique for wireless
communications. IEEE JSAC, 16: 1451–
1458.
[12] Goldsmith A., et al. (2003) Capacity Limits
of MIMO Channels. IEEE JSAC, 21: 684–
702.
[13] Stuart H. R. (2000) Dispersive multiplexing
in multi-mode optical fiber. Science, 289:
281–283.
[14] Tse D. N. C., et al. (2004) Diversity-
multiplexing tradeoff in multiple access
channels. IEEE Trans. Information Theory,
50: 1859–1873.
[15] Goldsmith A. (2005) Wireless
Communications. New York: Cambridge
University Press.
[16] Siew J., et al. (2002) A Channel Estimation
Method for MIMO-OFDM Systems.
London Communications Symposium,
London.
[17] Winters J.H. (1994) The diversity gain of
transmit diversity in wireless systems with
Rayleigh fading. IEEE International
Conference on Communications, (New
Orleans, LA): 1121– 1125.
[18] Tarokh V., Jafarkhani H. and Calderbank
A.R. (1999) Space-time block codes from
orthogonal designs. IEEE Transactions on
Information Theory, 45(5); 1456–1467.