This document summarizes the results of simulations comparing the bit error rate (BER) performance of different modulation schemes in a 2x2 MIMO system using Almouti space-time coding. The key findings are:
1) Higher order modulation schemes like QPSK, 16-QAM, and 64-QAM require more energy (i.e. higher Eb/No ratio) than lower order schemes like BPSK to achieve the same BER performance.
2) 16-QAM requires less energy than 16-PSK to achieve the same BER, since QAM signal points are distributed without being confined to a circle like PSK.
3) Simulated BER performance matches theoretical curves closely for Q
A COMPREHENSIVE STUDY AND PERFORMANCE COMPARISON OF M-ARY MODULATION SCHEMES ...IJCSEA Journal
Wireless communications has become one of the fastest growing areas in our modern life and creates enormous impact on nearly every feature of our daily life. In this paper, the performance of M-ary modulations schemes (MPSK, MQAM, MFSK) based wireless communication system on audio signal transmission over Additive Gaussian Noise (AWGN) channel are analyzed in terms of bit error probability as a function of SNR. Based on the results obtained in the present study, MPSK and MQAM are showing better performance for lower modulation order whereas these are inferior with higher M. The BER value is smaller in MFSK for higher M, but it is worse due to the distortion in the reproduce signal at the receiver end. The lossless reproduction of recorded voice signal can be achieved at the receiver end with a lower modulation order.
The efficient interleaving of digital-video-broadcasting-satellite 2nd genera...TELKOMNIKA JOURNAL
The DVB-S2 system is designed as a toolbox to permit the execution of the satellite programs. Interleaver is an essential part of the DVB-S2 system. The current general block interleaver in DVB-S2 is not best, which leads to high BER and maybe not satisfy the requirements of the system. The purpose of this paper is to study the several interleaver types and comparative analyses are done between them to find which of these give better performance. Simulations results obtained prove that the 2D interleavers minimize BER more than other interleavers of DVB-S2. Further, the performance of 2D interleaver is better on a system that required a low SNR.
Wideband Modeling of Twisted-Pair Cables for MIMO ApplicationsLantiq
Computer modeling and simulation approach to speed development of broadband networking technologies. http://bit.ly/1853xoY
More on our expertise: http://www.lantiq.com
Energy Efficiency of MIMO-OFDM Communication SystemIJERA Editor
With the ever increasing number of subscribers and their seemingly “greedy” demands for high-data-rate services, the next generation networks will have to provide global connectivity to ensure success. So the combination of multiple-input multiple-output (MIMO) signal processing with orthogonal frequency division multiplexing (OFDM) is regarded as a promising solution for enhancing the data rates of next-generation wireless communication systems operating in frequency-selective fading environments. Therefore hybrid architecture between terrestrial and satellite networks based on MIMO-OFDM with frequency reuse is employed here. However, this frequency reuse introduces severe co-channel interference (CCI) at the satellite end. To mitigate CCI, we propose an OFDM based adaptive beamformer implemented on-board the satellite with pilot reallocation at the transmitter side. The system performance is simulated by using the software MATLAB, the experimental result shows that the MIMO-OFDM communication system has better performance when compared.
Abstract –The energy efficiency has become more important in MIMO wireless communication system in recent days. The antennas at each end of the communications circuit are combined to minimize errors and optimize data speed. In Multiple Input Multiple Output Time Division Duplexing (MIMO TDD), by assuming reciprocity property the downlink transmission is based on uplink channel estimation. When more uplink pilot power ensures more accurate channel estimation and better downlink performance, it achieves higher energy consumption of mobile users. Link adaptation scheme uses different modulation schemes for different communication link quality. From the result of MIMO TDD, it ensures high Bit Error Rate.MIMO schemes are usually incorporated intoOFDM systems. The spatial and frequencyresource can be jointly allocated to improve EE.However, the complexity of the joint design may be prohibitive. This system is effective, in addition to that it also needs simple algorithms like energy efficiency optimization power allocation (EEOPA) algorithm of multiuser multiple input and multiple output (MU-MIMO) systems in order to obtain a trade-offbetween complexity and performance.
A COMPREHENSIVE STUDY AND PERFORMANCE COMPARISON OF M-ARY MODULATION SCHEMES ...IJCSEA Journal
Wireless communications has become one of the fastest growing areas in our modern life and creates enormous impact on nearly every feature of our daily life. In this paper, the performance of M-ary modulations schemes (MPSK, MQAM, MFSK) based wireless communication system on audio signal transmission over Additive Gaussian Noise (AWGN) channel are analyzed in terms of bit error probability as a function of SNR. Based on the results obtained in the present study, MPSK and MQAM are showing better performance for lower modulation order whereas these are inferior with higher M. The BER value is smaller in MFSK for higher M, but it is worse due to the distortion in the reproduce signal at the receiver end. The lossless reproduction of recorded voice signal can be achieved at the receiver end with a lower modulation order.
The efficient interleaving of digital-video-broadcasting-satellite 2nd genera...TELKOMNIKA JOURNAL
The DVB-S2 system is designed as a toolbox to permit the execution of the satellite programs. Interleaver is an essential part of the DVB-S2 system. The current general block interleaver in DVB-S2 is not best, which leads to high BER and maybe not satisfy the requirements of the system. The purpose of this paper is to study the several interleaver types and comparative analyses are done between them to find which of these give better performance. Simulations results obtained prove that the 2D interleavers minimize BER more than other interleavers of DVB-S2. Further, the performance of 2D interleaver is better on a system that required a low SNR.
Wideband Modeling of Twisted-Pair Cables for MIMO ApplicationsLantiq
Computer modeling and simulation approach to speed development of broadband networking technologies. http://bit.ly/1853xoY
More on our expertise: http://www.lantiq.com
Energy Efficiency of MIMO-OFDM Communication SystemIJERA Editor
With the ever increasing number of subscribers and their seemingly “greedy” demands for high-data-rate services, the next generation networks will have to provide global connectivity to ensure success. So the combination of multiple-input multiple-output (MIMO) signal processing with orthogonal frequency division multiplexing (OFDM) is regarded as a promising solution for enhancing the data rates of next-generation wireless communication systems operating in frequency-selective fading environments. Therefore hybrid architecture between terrestrial and satellite networks based on MIMO-OFDM with frequency reuse is employed here. However, this frequency reuse introduces severe co-channel interference (CCI) at the satellite end. To mitigate CCI, we propose an OFDM based adaptive beamformer implemented on-board the satellite with pilot reallocation at the transmitter side. The system performance is simulated by using the software MATLAB, the experimental result shows that the MIMO-OFDM communication system has better performance when compared.
Abstract –The energy efficiency has become more important in MIMO wireless communication system in recent days. The antennas at each end of the communications circuit are combined to minimize errors and optimize data speed. In Multiple Input Multiple Output Time Division Duplexing (MIMO TDD), by assuming reciprocity property the downlink transmission is based on uplink channel estimation. When more uplink pilot power ensures more accurate channel estimation and better downlink performance, it achieves higher energy consumption of mobile users. Link adaptation scheme uses different modulation schemes for different communication link quality. From the result of MIMO TDD, it ensures high Bit Error Rate.MIMO schemes are usually incorporated intoOFDM systems. The spatial and frequencyresource can be jointly allocated to improve EE.However, the complexity of the joint design may be prohibitive. This system is effective, in addition to that it also needs simple algorithms like energy efficiency optimization power allocation (EEOPA) algorithm of multiuser multiple input and multiple output (MU-MIMO) systems in order to obtain a trade-offbetween complexity and performance.
Performance evaluation of 1 tbps qpsk dwdm system over isowceSAT Journals
Abstract Optical wireless communications has been in latest trends of high speed communications. They enable the use of optical wireless channel in applications like inter satellite links and underwater communications etc. In this paper, we communicate an ultra high bit rate i.e. 1 Tbps (10 x 100 Gbps) QPSK WDM System over optical Wireless communication Link. The system is a Line of Sight optical wireless link incorporating Coherent QPSK modulation Scheme for10 channels each at 100 Gbps The performance is evaluated in terms of Q-Factor and Minimum Bit Error Rate which are noticed to be in acceptable standards. The Link is analyzed under various parameters such as Power, Distance etc and maximum achievable distance is noticed to be 50,000 km at power values ranging from 0 dBm to 40 dBm
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.
ICI and PAPR enhancement in MIMO-OFDM system using RNS codingIJECEIAES
The Inter-Carrier-Interference (ICI) is considered a bottleneck in the utilization of Multiple-Input-Multiple-Output Orthogonal Frequency Division Multiplexing (MIMO-OFDM) systems, due to the sensitivity of the OFDM towards frequency offsets which lead to loss of orthogonality, interference and performance degradation. In this paper Residue Numbers as a coding scheme is impeded in MIMO-OFDM systems, where the ICI levels is measured and evaluated with respect to conventional ICI mitigation techniques implemented in MIMO-OFDM. The Carrier-to-Interference Ratio (CIR), the system Bit-Error-Rate (BER) and the Complementary Cumulative Distribution Function (CCDF) for MIMO-OFDM system with Residue Number System (RNS) coding are analyzed and evaluated. The results had demonstrated a performance of transmission model with and without RNS.
An Adaptive Algorithm for MU-MIMO using Spatial Channel ModelCSCJournals
In this paper, Multi User Multiple Input Multiple Output (MU-MIMO) spatial channel model has been implemented for different outdoor environments – Urban Micro, and Urban Macro using MATLAB for finding various parameters like angle of arrival of the user, user direction and the distance between user and access point (AP).
Grayscale Image Transmission over Rayleigh Fading Channel in a MIMO System Us...IJERA Editor
The consistent demand for higher data rates and ability to send large volumes of data without compromising the quality of communication has led the development of a new generations of wireless systems. But range and data rate limitations are there in wireless devices. In an effort to overcome these limitations, Multi Input Multi Output (MIMO) systems can be used which also increase diversity and improve the bit error rate (BER) performance of wireless systems. They also increase the channel capacity, increase the transmitted data rate through spatial multiplexing, and/or reduce interference from other users. MIMO systems thus make a promising communication systems because of their high transmission rates without additional bandwidth or transmit power and robustness against multipath fading. This paper focuses on transmission of an image file using 2x2 MIMO system that achieves a full diversity gain using Alamouti’s Space Time Block Coding technique for 2 transmitting antennas and 2 receiving antennas. Different modulation techniques viz. BPSK, QPSK, 16-QAM and 64-QAM are used and performances has been evaluated in terms of BER vs. SNR to find out the best modulation technique in a given environment. Space-Time Codes have been used which in addition to the time and spectral domain, also exploit the spatial domain. Simple maximum likelihood decoding algorithm is used at the receiver side to decode the received encoded signal.
Computationally Efficient Multi-Antenna Techniques for Multi-User Two-Way Wire...IJECEIAES
In this work, we are interested in implementing, developing and evaluating multi-antenna techniques used for multi-user two-way wireless relay networks that provide a good tradeoff between the computational complexity and performance in terms of symbol error rate and achievable data rate. In particular, a variety of newly multi-antenna techniques is proposed and studied. Some techniques based on orthogonal projection enjoy low computational complexity. However, the performance penalty associated with them is high. Other techniques based on maximum likelihood strategy enjoy high performance, however, they suffer from very high computational complexity. The Other techniques based on randomization strategy provide a good trade-off between the computational complexity and performance where they enjoy low computational complexity with almost the same performance as compared to the techniques based on maximum likelihood strategy.
Signal Strength Evaluation of a 3G Network in Owerri Metropolis Using Path Lo...Onyebuchi nosiri
Abstract: In this work, the path loss and the received signal strength of a 3G network at 2.1GHz was evaluated to determine its performance within the Owerri metropolis. Various measuring equipment such as Transmission Evaluation and Monitoring System (TEMS 11), Global positioning system (BU353 GPS) and laptop were deployed for the drive test within the selected urban and sub-urban regions. From the data collected, Owerri sub-urban region showed poor received signal power level compared to the Owerri urban region. The path loss exponents computed for the Owerri urban and sub-urban regions are 3.24 and 4.34 respectively, the mean square error was evaluated as 1.96 and 1.68. The result obtained showed deviations between the compared existing models (Hata and Cost 231) and the proposed models. However, the slope of the Hata plot was relatively close in comparison to the proposed model than that of Cost 231; hence, the proposed model was best suited for the environment followed by the Hata model.
A Weighted Duality based Formulation of MIMO SystemsIJERA Editor
This work is based on the modeling and analysis of multiple-input multiple-output (MIMO) system in downlink communication system. We take into account a recent work on the ratio of quadratic forms to formulate the weight matrices of quadratic norm in a duality structure. This enables us to achieve exact solutions for MIMO system operating under Rayleigh fading channels. We outline couple of scenarios dependent on the structure of eigenvalues to investigate the system behavior. The results obtained are validated by means of Monte Carlo simulations.
Energy-efficient user association mechanism enabling fully hybrid spectrum sh...TELKOMNIKA JOURNAL
Spectrum sharing (SS) is a promising solution to enhance spectrum utilization in future cellular
systems. Reducing the energy consumption in cellular networks has recently earned tremendous attention
from diverse stakeholders (i.e., vendors, mobile network operators (MNOs), and government) to decrease
the CO2 emissions and thus introducing an environment-friendly wireless communication. Therefore,
in this paper, joint energy-efficient user association (UA) mechanism and fully hybrid spectrum sharing
(EE-FHSS) approach is proposed considering the quality of experience QoE (i.e., data rate) as the main
constraint. In this approach, the spectrum available in the high and low frequencies (28 and 73 GHz) is
sliced into three portions (licensed, semi-shared, and fully-shared) aims to serve the users (UEs)
that belong to four operators in an integrated and hybrid manner. The performance of the proposed
QoE-Based EE UA-FHSS is compared with the well-known maximum signal-to-interference-plus-noise
ratio (max-SINR UA-FHSS). Numerical results show that remarkable enhancement in terms of EE for
the four participating operators can be achieved while maintaining a high degree of QoE to the UEs.
Bit-error-rate Optimization for CDMA Ultra-wideband System Using Generalized ...IJECEIAES
Ultra-wideband is a wireless technology arisen for future high speed multimedia applications. It can provide data rate in excess of Gigabits per second by transmitting impulse signal through the free space. However, the ultra-wideband indoor channel models proposed by the IEEE P802.15.3a suffer long multipath propagation. Due to this multipath effect, several studies have been done to improve the bit-error-rate performance of the ultrawideband system in the existence of severe interference. Yet, most of the proposed algorithms were formulated based on the Gaussian distribution, which is not true in ultra-wideband. In this paper, we first analyze the statistical behavior of the CDMA-UWB signal by applying the KullbackLeibler divergence index. Based on the analysis, a non-Gaussian equalizer is developed by deriving an enhanced bit-error-rate optimization algorithm using the Generalized Gaussian approach. The proposed equalizer has been shown to achieve a performance gain of at least 1.5dB to 2dB over the other equalizers simulated under IEEE P802.15.3a channel models.
A Low Power High Bandwidth Four Quadrant Analog Multiplier in 32 NM CNFET Tec...VLSICS Design
Carbon Nanotube Field Effect Transistor (CNFET) is a promising new technology that overcomes several limitations of traditional silicon integrated circuit technology. In recent years, the potential of CNFET for analog circuit applications has been explored. This paper proposes a novel four quadrant analog multiplier design using CNFETs. The simulation based on 32nm CNFET technology shows that the proposed multiplier has very low harmonic distortion (<0.45%), large input range (±400mV), large bandwidth (~50GHz) and low power consumption (~247µW), while operating at a supply voltage of ±0.9V.
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
A detection technique of signal in mimo systemeSAT Journals
Abstract MIMO techniques are based on multiple antennae in receiving and transmitting signals and also used in multipath propagation for the transformation of entire channel into many independent virtual channels. In MIMO system multiple antennae can increase the spectral efficiency/ reliability of radio channel without increasing bandwidth or transmit power. Commercially, it is not feasible in case of MIMO systems. So, simple and efficient receiver that can harness MIMO architecture benefits without draining mobile receiver battery power or long time to decode transmitted symbols was required. In this paper problem of receiver design for MIMO system in spatial multiplexing scheme that is Maximum likelihood detection problem also known as NP hard combinatorial optimization problem, which need an exponential search over the space of all possible transmitted symbols in order to find closest point in Euclidean sense to received symbols, has been considered. A metaheuristic algorithm for detection of MIMO wireless system based on the Ant colony optimization (ACO) technique using MATLAB give the best solution to the problem and find the optimal path for the receivers. Keywords: ACO, CO- combinatorial optimization, MATLAB, Metaheuristic, MIMO, NP Hard-non deterministic polynomial time hard, QAM- quadratic amplitude modulation
International Journal of Computational Engineering Research(IJCER) is an intentional online Journal in English monthly publishing journal. This Journal publish original research work that contributes significantly to further the scientific knowledge in engineering and Technology.
A Novel Alamouti STBC Technique for MIMO System Using 16- QAM Modulation and ...IJERA Editor
The wireless communication is the emerging field of research among communication researchers and they are
continuously working towards the reduction if error occurred in the signal during transmission through wireless
media. In this paper the wireless system is simulated with the application of Alamouti space time block codes
(STBC) with MIMO and MISO configurations to compare the results. The modulation technique used here is
16-QAM which is giving better results than other counterparts and to enhance the performance of the system i.e.
to reduce the effect of errors on data we have applied a moving average filter(MAF). The performance of the
system is shown with the simulation results with variable data sizes and found that the proposed approach is
better for the system.
In this paper, Space Time Block Code (STBC), Spatial Multiplexing (SM) and hybrid model with OFDM
are designed for Rayleigh fading channel. Combination of SM and STBC forms hybrid MIMO model. The
performances of the above mentioned models with different modulations such as Quadrature Phase Shift
Keying (QPSK) and Quadrature Amplitude Modulation (QAM) with multiple antennas are measured with
respect to BER. In this paper, it is shown that Hybrid MIMO provides low BER. Thus, in wireless
communication, hybrid model improves the data rate and link reliability.
Performance analysis of negative group delay network using MIMO techniqueTELKOMNIKA JOURNAL
This study introduces comparative consequences that determine the bit error rate enhancements, resultant from adopting a proposed MIMO wireless model in this study. The antenna configurations for this model uses new small microstrip slotted patch antenna with multiple frequency bands at strategic operating frequencies of 2.4, 4.4, and 5.55 respectively. The S11 response of the proposed antenna for IEEE802.11 MIMO wireless network has been highly appropriate to be adopted with MIMO antenna system. The negative group delay (NGD) response is the most significant feature for projected MIMO antenna. The NGD stands for a counterintuitive singularity that interacts time advancement with wave propagation. These improvements are employed for increasing a reliability of instantly conveyed data streams, enhance the capacity of the wireless configuration and decrease the bit error rate (BER) of adopted wireless system. In addition to antenna scattering response, the enhancements have been analysed in term of BER for different MIMO topologies.
Performance evaluation of 1 tbps qpsk dwdm system over isowceSAT Journals
Abstract Optical wireless communications has been in latest trends of high speed communications. They enable the use of optical wireless channel in applications like inter satellite links and underwater communications etc. In this paper, we communicate an ultra high bit rate i.e. 1 Tbps (10 x 100 Gbps) QPSK WDM System over optical Wireless communication Link. The system is a Line of Sight optical wireless link incorporating Coherent QPSK modulation Scheme for10 channels each at 100 Gbps The performance is evaluated in terms of Q-Factor and Minimum Bit Error Rate which are noticed to be in acceptable standards. The Link is analyzed under various parameters such as Power, Distance etc and maximum achievable distance is noticed to be 50,000 km at power values ranging from 0 dBm to 40 dBm
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.
ICI and PAPR enhancement in MIMO-OFDM system using RNS codingIJECEIAES
The Inter-Carrier-Interference (ICI) is considered a bottleneck in the utilization of Multiple-Input-Multiple-Output Orthogonal Frequency Division Multiplexing (MIMO-OFDM) systems, due to the sensitivity of the OFDM towards frequency offsets which lead to loss of orthogonality, interference and performance degradation. In this paper Residue Numbers as a coding scheme is impeded in MIMO-OFDM systems, where the ICI levels is measured and evaluated with respect to conventional ICI mitigation techniques implemented in MIMO-OFDM. The Carrier-to-Interference Ratio (CIR), the system Bit-Error-Rate (BER) and the Complementary Cumulative Distribution Function (CCDF) for MIMO-OFDM system with Residue Number System (RNS) coding are analyzed and evaluated. The results had demonstrated a performance of transmission model with and without RNS.
An Adaptive Algorithm for MU-MIMO using Spatial Channel ModelCSCJournals
In this paper, Multi User Multiple Input Multiple Output (MU-MIMO) spatial channel model has been implemented for different outdoor environments – Urban Micro, and Urban Macro using MATLAB for finding various parameters like angle of arrival of the user, user direction and the distance between user and access point (AP).
Grayscale Image Transmission over Rayleigh Fading Channel in a MIMO System Us...IJERA Editor
The consistent demand for higher data rates and ability to send large volumes of data without compromising the quality of communication has led the development of a new generations of wireless systems. But range and data rate limitations are there in wireless devices. In an effort to overcome these limitations, Multi Input Multi Output (MIMO) systems can be used which also increase diversity and improve the bit error rate (BER) performance of wireless systems. They also increase the channel capacity, increase the transmitted data rate through spatial multiplexing, and/or reduce interference from other users. MIMO systems thus make a promising communication systems because of their high transmission rates without additional bandwidth or transmit power and robustness against multipath fading. This paper focuses on transmission of an image file using 2x2 MIMO system that achieves a full diversity gain using Alamouti’s Space Time Block Coding technique for 2 transmitting antennas and 2 receiving antennas. Different modulation techniques viz. BPSK, QPSK, 16-QAM and 64-QAM are used and performances has been evaluated in terms of BER vs. SNR to find out the best modulation technique in a given environment. Space-Time Codes have been used which in addition to the time and spectral domain, also exploit the spatial domain. Simple maximum likelihood decoding algorithm is used at the receiver side to decode the received encoded signal.
Computationally Efficient Multi-Antenna Techniques for Multi-User Two-Way Wire...IJECEIAES
In this work, we are interested in implementing, developing and evaluating multi-antenna techniques used for multi-user two-way wireless relay networks that provide a good tradeoff between the computational complexity and performance in terms of symbol error rate and achievable data rate. In particular, a variety of newly multi-antenna techniques is proposed and studied. Some techniques based on orthogonal projection enjoy low computational complexity. However, the performance penalty associated with them is high. Other techniques based on maximum likelihood strategy enjoy high performance, however, they suffer from very high computational complexity. The Other techniques based on randomization strategy provide a good trade-off between the computational complexity and performance where they enjoy low computational complexity with almost the same performance as compared to the techniques based on maximum likelihood strategy.
Signal Strength Evaluation of a 3G Network in Owerri Metropolis Using Path Lo...Onyebuchi nosiri
Abstract: In this work, the path loss and the received signal strength of a 3G network at 2.1GHz was evaluated to determine its performance within the Owerri metropolis. Various measuring equipment such as Transmission Evaluation and Monitoring System (TEMS 11), Global positioning system (BU353 GPS) and laptop were deployed for the drive test within the selected urban and sub-urban regions. From the data collected, Owerri sub-urban region showed poor received signal power level compared to the Owerri urban region. The path loss exponents computed for the Owerri urban and sub-urban regions are 3.24 and 4.34 respectively, the mean square error was evaluated as 1.96 and 1.68. The result obtained showed deviations between the compared existing models (Hata and Cost 231) and the proposed models. However, the slope of the Hata plot was relatively close in comparison to the proposed model than that of Cost 231; hence, the proposed model was best suited for the environment followed by the Hata model.
A Weighted Duality based Formulation of MIMO SystemsIJERA Editor
This work is based on the modeling and analysis of multiple-input multiple-output (MIMO) system in downlink communication system. We take into account a recent work on the ratio of quadratic forms to formulate the weight matrices of quadratic norm in a duality structure. This enables us to achieve exact solutions for MIMO system operating under Rayleigh fading channels. We outline couple of scenarios dependent on the structure of eigenvalues to investigate the system behavior. The results obtained are validated by means of Monte Carlo simulations.
Energy-efficient user association mechanism enabling fully hybrid spectrum sh...TELKOMNIKA JOURNAL
Spectrum sharing (SS) is a promising solution to enhance spectrum utilization in future cellular
systems. Reducing the energy consumption in cellular networks has recently earned tremendous attention
from diverse stakeholders (i.e., vendors, mobile network operators (MNOs), and government) to decrease
the CO2 emissions and thus introducing an environment-friendly wireless communication. Therefore,
in this paper, joint energy-efficient user association (UA) mechanism and fully hybrid spectrum sharing
(EE-FHSS) approach is proposed considering the quality of experience QoE (i.e., data rate) as the main
constraint. In this approach, the spectrum available in the high and low frequencies (28 and 73 GHz) is
sliced into three portions (licensed, semi-shared, and fully-shared) aims to serve the users (UEs)
that belong to four operators in an integrated and hybrid manner. The performance of the proposed
QoE-Based EE UA-FHSS is compared with the well-known maximum signal-to-interference-plus-noise
ratio (max-SINR UA-FHSS). Numerical results show that remarkable enhancement in terms of EE for
the four participating operators can be achieved while maintaining a high degree of QoE to the UEs.
Bit-error-rate Optimization for CDMA Ultra-wideband System Using Generalized ...IJECEIAES
Ultra-wideband is a wireless technology arisen for future high speed multimedia applications. It can provide data rate in excess of Gigabits per second by transmitting impulse signal through the free space. However, the ultra-wideband indoor channel models proposed by the IEEE P802.15.3a suffer long multipath propagation. Due to this multipath effect, several studies have been done to improve the bit-error-rate performance of the ultrawideband system in the existence of severe interference. Yet, most of the proposed algorithms were formulated based on the Gaussian distribution, which is not true in ultra-wideband. In this paper, we first analyze the statistical behavior of the CDMA-UWB signal by applying the KullbackLeibler divergence index. Based on the analysis, a non-Gaussian equalizer is developed by deriving an enhanced bit-error-rate optimization algorithm using the Generalized Gaussian approach. The proposed equalizer has been shown to achieve a performance gain of at least 1.5dB to 2dB over the other equalizers simulated under IEEE P802.15.3a channel models.
A Low Power High Bandwidth Four Quadrant Analog Multiplier in 32 NM CNFET Tec...VLSICS Design
Carbon Nanotube Field Effect Transistor (CNFET) is a promising new technology that overcomes several limitations of traditional silicon integrated circuit technology. In recent years, the potential of CNFET for analog circuit applications has been explored. This paper proposes a novel four quadrant analog multiplier design using CNFETs. The simulation based on 32nm CNFET technology shows that the proposed multiplier has very low harmonic distortion (<0.45%), large input range (±400mV), large bandwidth (~50GHz) and low power consumption (~247µW), while operating at a supply voltage of ±0.9V.
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
A detection technique of signal in mimo systemeSAT Journals
Abstract MIMO techniques are based on multiple antennae in receiving and transmitting signals and also used in multipath propagation for the transformation of entire channel into many independent virtual channels. In MIMO system multiple antennae can increase the spectral efficiency/ reliability of radio channel without increasing bandwidth or transmit power. Commercially, it is not feasible in case of MIMO systems. So, simple and efficient receiver that can harness MIMO architecture benefits without draining mobile receiver battery power or long time to decode transmitted symbols was required. In this paper problem of receiver design for MIMO system in spatial multiplexing scheme that is Maximum likelihood detection problem also known as NP hard combinatorial optimization problem, which need an exponential search over the space of all possible transmitted symbols in order to find closest point in Euclidean sense to received symbols, has been considered. A metaheuristic algorithm for detection of MIMO wireless system based on the Ant colony optimization (ACO) technique using MATLAB give the best solution to the problem and find the optimal path for the receivers. Keywords: ACO, CO- combinatorial optimization, MATLAB, Metaheuristic, MIMO, NP Hard-non deterministic polynomial time hard, QAM- quadratic amplitude modulation
International Journal of Computational Engineering Research(IJCER) is an intentional online Journal in English monthly publishing journal. This Journal publish original research work that contributes significantly to further the scientific knowledge in engineering and Technology.
A Novel Alamouti STBC Technique for MIMO System Using 16- QAM Modulation and ...IJERA Editor
The wireless communication is the emerging field of research among communication researchers and they are
continuously working towards the reduction if error occurred in the signal during transmission through wireless
media. In this paper the wireless system is simulated with the application of Alamouti space time block codes
(STBC) with MIMO and MISO configurations to compare the results. The modulation technique used here is
16-QAM which is giving better results than other counterparts and to enhance the performance of the system i.e.
to reduce the effect of errors on data we have applied a moving average filter(MAF). The performance of the
system is shown with the simulation results with variable data sizes and found that the proposed approach is
better for the system.
In this paper, Space Time Block Code (STBC), Spatial Multiplexing (SM) and hybrid model with OFDM
are designed for Rayleigh fading channel. Combination of SM and STBC forms hybrid MIMO model. The
performances of the above mentioned models with different modulations such as Quadrature Phase Shift
Keying (QPSK) and Quadrature Amplitude Modulation (QAM) with multiple antennas are measured with
respect to BER. In this paper, it is shown that Hybrid MIMO provides low BER. Thus, in wireless
communication, hybrid model improves the data rate and link reliability.
Performance analysis of negative group delay network using MIMO techniqueTELKOMNIKA JOURNAL
This study introduces comparative consequences that determine the bit error rate enhancements, resultant from adopting a proposed MIMO wireless model in this study. The antenna configurations for this model uses new small microstrip slotted patch antenna with multiple frequency bands at strategic operating frequencies of 2.4, 4.4, and 5.55 respectively. The S11 response of the proposed antenna for IEEE802.11 MIMO wireless network has been highly appropriate to be adopted with MIMO antenna system. The negative group delay (NGD) response is the most significant feature for projected MIMO antenna. The NGD stands for a counterintuitive singularity that interacts time advancement with wave propagation. These improvements are employed for increasing a reliability of instantly conveyed data streams, enhance the capacity of the wireless configuration and decrease the bit error rate (BER) of adopted wireless system. In addition to antenna scattering response, the enhancements have been analysed in term of BER for different MIMO topologies.
Index modulation is one of the promising techniques for future communications systems due to many improvement over the classical orthogonal frequency division multiplexing systems such as single RF chain, increased throughput for the same modulation order, achieved tradeoff between the efficiencies of the power and the spectral, and elimination of inter-channel interference. Many forms of index modulation researches exist where symbols are conveyed in antennas, subcarriers, time slots, and the space-time matrix. Spatial modulation is one member of index modulation family where symbols are conveyed in activating transmit/receive antennas. In this paper, a modification to a standard multiple input single output scheme by integrating spatial modulation using simplified mathematical procedure is achieved. In the transmitter side, data and activation symbols are distributed simultaneously using mathematical module and floor functions. At the receiver, a simplified maximum likelihood detector is used to obtain transmitted pair of symbols. To verify this, MATLAB simulink is used to simulate a downlink system where spatial modulation is applied to a base station. Results for different transmit antenna number and modulation order are obtained in the form of bit error rate versus signal to noise ratio.
Evaluation of the weighted-overlap add model with massive MIMO in a 5G systemTELKOMNIKA JOURNAL
The flaw in 5G orthogonal frequency division multiplexing (OFDM) becomes apparent in high-speed situations. Because the doppler effect causes frequency shifts, the orthogonality of OFDM subcarriers is broken, lowering both their bit error rate (BER) and throughput output. As part of this research, we use a novel design that combines massive multiple input multiple output (MIMO) and weighted overlap and add (WOLA) to improve the performance of 5G systems. To determine which design is superior, throughput and BER are calculated for both the proposed design and OFDM. The results of the improved system show a massive improvement in performance ver the conventional system and significant improvements with massive MIMO, including the best throughput and BER. When compared to conventional systems, the improved system has a throughput that is around 22% higher and the best performance in terms of BER, but it still has around 25% less error than OFDM.
Performance of the MIMO-MC-CDMA System with MMSE EqualizationTamilarasan N
Multipath fading and spectral crowding are the
major challenges in dealing higher data rate in future
broadband wireless communication system. Multi-carrier
Modulation like Multicarrier code division multiple access
(MC-CDMA) can tackle the problem and provide higher data
rate for future wireless communication system. However,
through a frequency selective fading channel, the subcarriers
in MC-CDMA signal have different amplitude levels and phase
shifts which result in loss of the orthogonality among users
and generates Multiple access interference (MAI). To combat
the MAI, various amplitude and phase equalizing techniques
such as Maximum Ratio Combining (MRC), Equal Gain
Combining (EGC), Orthogonal Restoring Combining (ORC),
Threshold Orthogonal Restoring Combining or Minimum
Mean Square Error (MMSE) may be used. Out of these MMSE
offers better performance since the MMSE criterion is applied
independently on each subcarrier. Further improvement in
performance is possible through space–time block coding,
which offers maximum diversity gain and multiplexing gain.
This paper combines MC-CDMA with MMSE equalization
and space–time block coding which proves to be a powerful
physical layer solution in combating delay spread and inter
symbol interference (ISI).
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.
DESIGN OF SECURE AND RELIABLE MU-MIMO TRANSCEIVER SYSTEM FOR VEHICULAR NETWORKSIJCNCJournal
Networks have become considerably large, complex and dynamic. The configuration, operation,
monitoring, and troubleshooting of networks is a cumbersome and time-consuming task for the network
administrators as they must deal with the physical layer, underlying protocols, addressing systems, control
rules, and many other low-level details. This research paper proposes an Intent-based networking system
(IBNS) coupled with voice-assistance that can abstract the underlying network infrastructure and allow
administrators to alter its behavior by expressing intents via voice commands. The system also displays the
real-time network topology along with the highlighted intents on an interactive web application that can be
used for network diagnostics. Compared to traditional networks, the concepts of software-defined
networking (S
An Integrated Approach of ACM and CDMA in a Novel Multi User Spatial Modulati...ijtsrd
The research focus in wireless communication access technologies is driven by the demand for high peak data rates and significantly improved spectral efficiencies, as well as the support for specific quality of service QoS requirements. By leveraging the orthogonality of space constellations and signal constellations, well established digital signal modulation schemes can be employed. The spatial multiplexing gain is achieved through the concurrent transmission of spatially encoded bits. This thesis investigates and compares the analytical and numerical performance of Spatial Modulation SM under various channel conditions, taking into account practical channel considerations, in comparison to existing MIMO techniques. The results demonstrate that SM achieves a low bit error ratio BER while substantially reducing receiver complexity, all while maintaining spectral efficiency. Kumari Kanchana | Dr. Prabhat Sharma "An Integrated Approach of ACM and CDMA in a Novel Multi-User Spatial Modulation Scheme" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-7 | Issue-4, August 2023, URL: https://www.ijtsrd.com/papers/ijtsrd59660.pdf Paper Url:https://www.ijtsrd.com/engineering/electronics-and-communication-engineering/59660/an-integrated-approach-of-acm-and-cdma-in-a-novel-multiuser-spatial-modulation-scheme/kumari-kanchana
Link Adaptation for Microwave Link using both MATLAB and Path-Loss Toolijeei-iaes
The inherent multipath transmission on wireless channels usually leads to signal fading which eventually degrades the system performance. In mitigating this problem, link adaptation has been identified as a promising scheme that helps in maximizing the system spectral efficiency (SE) in dispersive wireless channels. In this paper, link adaptation based on adaptive modulation and coding was used to study the performance of M-ary quadrature amplitude modulation radio system subjected to multipath fading. MATLAB® scripts and Simulink model were developed to compare the effect of wireless channel on different constellation sizes. Also, transmission link on Federal University of Technology Akure campus’ path terrain was designed with the aid of path-loss® tool application software in order to further analysis the effect of using different modulation formats on the system performance. The results show that, employment of link adaptation scheme offers better performance regarding the system availability and SE
Wireless communication now has been focus to increase data rate and high performance. The
multi carrier on multi-hop communication system using relay's diversity technique which is
supported by a reliable coding is a system that may give high performance.
This research is developing a model of multi carrier CDMA on multi hop communication
system with diversity technique which is using Alamouti codes in Rayleigh fading channel. By
Alamouti research, Space Time Block Code (STBC) for MIMO system can perform high quality
signal at the receiver in the Rayleigh fading channel and the noisy system. In this research,
MIMO by STBC is applied to single antenna system (Distributed-STBC/DSTBC) with multi
carrier CDMA on multi hop wireless communication system (relay diversity) which is able to
reduce the complexity of the system but the system performance even can be maintained and
improved.
MC CDMA on multi hop wireless communication system with 2 hops is performing much better
than Single Input Single Output (SISO) system (1 hop system). Power needed for 1 hop system to
have the same quality as 2 hops system to reach BER 10-3 is 12 dB. And multi hop system needs
orthogonal symbol to send from relay than original symbol to reach better performance. 12.5
dB power up is needed for multi hop system which sent same symbol as transmitter than relay
system which sent orthogonal symbol.
MC CDMA PERFORMANCE ON SINGLE RELAY COOPERATIVE SYSTEM BY DIVERSITY TECHNIQUE...cscpconf
Wireless communication now has been focus to increase data rate and high performance. The multi carrier on multi-hop communication system using relay's diversity technique which is
supported by a reliable coding is a system that may give high performance. This research is developing a model of multi carrier CDMA on multi hop communication system with diversity technique which is using Alamouti codes in Rayleigh fading channel. By Alamouti research, Space Time Block Code (STBC) for MIMO system can perform high quality signal at the receiver in the Rayleigh fading channel and the noisy system. In this research, MIMO by STBC is applied to single antenna system (Distributed-STBC/DSTBC) with multi carrier CDMA on multi hop wireless communication system (relay diversity) which is able to reduce the complexity of the system but the system performance even can be maintained andimproved.
MC CDMA on multi hop wireless communication system with 2 hops is performing much better than Single Input Single Output (SISO) system (1 hop system). Power needed for 1 hop system to have the same quality as 2 hops system to reach BER 10-3 is 12 dB. And multi hop system needs orthogonal symbol to send from relay than original symbol to reach better performance. 12.5 dB power up is needed for multi hop system which sent same symbol as transmitter than relay system which sent orthogonal symbol.
Performance enhancement of maximum ratio transmission in 5G system with multi...IJECEIAES
The downlink multi-user precoding of the multiple-input multiple-output (MIMO) method includes optimal channel state information at the base station and a variety of linear precoding (LP) schemes. Maximum ratio transmission (MRT) is among the common precoding schemes but does not provide good performance with massive MIMO, such as high bit error rate (BER) and low throughput. The orthogonal frequency division multiplexing (OFDM) and precoding schemes used in 5G have a flaw in high-speed environments. Given that the Doppler effect induces frequency changes, orthogonality between OFDM subcarriers is disrupted and their throughput output is decreased and BER is decreased. This study focuses on solving this problem by improving the performance of a 5G system with MRT, specifically by using a new design that includes weighted overlap and add (WOLA) with MRT. The current research also compares the standard system MRT with OFDM with the proposed design (WOLA-MRT) to find the best performance on throughput and BER. Improved system results show outstanding performance enhancement over a standard system, and numerous improvements with massive MIMO, such as best BER and throughput. Its approximately 60% more throughput than the traditional systems. Lastly, the proposed system improves BER by approximately 2% compared with the traditional system.
PERFORMANCE OF CONVOLUTION AND CRC CHANNEL ENCODED V-BLAST 4×4 MIMO MCCDMA WI...ijasa
Wireless communications are among the rapidly growing fields in our current life and have a massive effect on every aspect of our everyday life. In this paper, the performance of the various digital modulation techniques (BPSK, DPSK, QPSK, and QAM) based wireless communication system on the audio signal transmission through the additive Gaussian Noise (AWGN) channel is assessed on the basis of bit error rate (BER) as a function of the signal-to-noise ratio (SNR). Based on the results of this study, BPSK modulation outperforms the DPSK, QPSK, and QAM modulation strategies in the MIMO MC-CDMA VBlast based wireless communication system. The digital modulation of QPSK shows the worst performance in audio signal transmission especially in comparison to other digital modulations. It is clear from the current simulation study based on MATLAB that the V-Blast encoded 4×4 MIMO MC-CDMA wireless system with minimum mean square error (MMSE) signal detection and 1⁄2-rated convolution and cyclic redundancy check (CRC) channel encoding strategies show good performance utilizing BPSK digital modulation in audio signal transmission
Similar to BER Performance of MPSK and MQAM in 2x2 Almouti MIMO Systems (20)
INFORMATION THEORY BASED ANALYSIS FOR UNDERSTANDING THE REGULATION OF HLA GEN...ijistjournal
Considering information entropy (IE), HLA surface expression (SE) regulation phenomenon is considered as information propagation channel with an amount of distortion. HLA gene SE is considered as sink regulated by the inducible transcription factors (TFs) (source). Previous work with a certain number of bin size, IEs for source and receiver is computed and computation of mutual information characterizes the dependencies of HLA gene SE on some certain TFs in different cells types of hematopoietic system under the condition of leukemia. Though in recent time information theory is utilized for different biological knowledge generation and different rules are available in those specific domains of biomedical areas; however, no such attempt is made regarding gene expression regulation, hence no such rule is available. In this work, IE calculation with varying bin size considering the number of bins is approximately half of the sample size of an attribute also confirms the previous inferences.
Call for Research Articles - 5th International Conference on Artificial Intel...ijistjournal
5th International Conference on Artificial Intelligence and Machine Learning (CAIML 2024) will provide an excellent international forum for sharing knowledge and results in theory, methodology and applications of Artificial Intelligence and Machine Learning. The Conference looks for significant contributions to all major fields of the Artificial Intelligence, Machine Learning in theoretical and practical aspects. The aim of the Conference is to provide a platform to the researchers and practitioners from both academia as well as industry to meet and share cutting-edge development in the field.
Authors are solicited to contribute to the conference by submitting articles that illustrate research results, projects, surveying works and industrial experiences that describe significant advances in the areas of Computer Science, Engineering and Applications.
Online Paper Submission - International Journal of Information Sciences and T...ijistjournal
The International Journal of Information Science & Techniques (IJIST) focuses on information systems science and technology coercing multitude applications of information systems in business administration, social science, biosciences, and humanities education, library sciences management, depiction of data and structural illustration, big data analytics, information economics in real engineering and scientific problems.
This journal provides a forum that impacts the development of engineering, education, technology management, information theories and application validation. It also acts as a path to exchange novel and innovative ideas about Information systems science and technology.
SYSTEM IDENTIFICATION AND MODELING FOR INTERACTING AND NON-INTERACTING TANK S...ijistjournal
System identification from the experimental data plays a vital role for model based controller design. Derivation of process model from first principles is often difficult due to its complexity. The first stage in the development of any control and monitoring system is the identification and modeling of the system. Each model is developed within the context of a specific control problem. Thus, the need for a general system identification framework is warranted. The proposed framework should be able to adapt and emphasize different properties based on the control objective and the nature of the behavior of the system. Therefore, system identification has been a valuable tool in identifying the model of the system based on the input and output data for the design of the controller. The present work is concerned with the identification of transfer function models using statistical model identification, process reaction curve method, ARX model, genetic algorithm and modeling using neural network and fuzzy logic for interacting and non interacting tank process. The identification technique and modeling used is prone to parameter change & disturbance. The proposed methods are used for identifying the mathematical model and intelligent model of interacting and non interacting process from the real time experimental data.
Call for Research Articles - 4th International Conference on NLP & Data Minin...ijistjournal
4th International Conference on NLP & Data Mining (NLDM 2024) will provide an excellent international forum for sharing knowledge and results in theory, methodology and applications of Natural Language Computing and Data Mining.
Authors are solicited to contribute to the conference by submitting articles that illustrate research results, projects, surveying works and industrial experiences that describe significant advances in the following areas, but are not limited to.
Research Article Submission - International Journal of Information Sciences a...ijistjournal
The International Journal of Information Science & Techniques (IJIST) focuses on information systems science and technology coercing multitude applications of information systems in business administration, social science, biosciences, and humanities education, library sciences management, depiction of data and structural illustration, big data analytics, information economics in real engineering and scientific problems.
This journal provides a forum that impacts the development of engineering, education, technology management, information theories and application validation. It also acts as a path to exchange novel and innovative ideas about Information systems science and technology.
Call for Papers - International Journal of Information Sciences and Technique...ijistjournal
The International Journal of Information Science & Techniques (IJIST) focuses on information systems science and technology coercing multitude applications of information systems in business administration, social science, biosciences, and humanities education, library sciences management, depiction of data and structural illustration, big data analytics, information economics in real engineering and scientific problems.
This journal provides a forum that impacts the development of engineering, education, technology management, information theories and application validation. It also acts as a path to exchange novel and innovative ideas about Information systems science and technology.
Implementation of Radon Transformation for Electrical Impedance Tomography (EIT)ijistjournal
Radon Transformation is generally used to construct optical image (like CT image) from the projection data in biomedical imaging. In this paper, the concept of Radon Transformation is implemented to reconstruct Electrical Impedance Topographic Image (conductivity or resistivity distribution) of a circular subject. A parallel resistance model of a subject is proposed for Electrical Impedance Topography(EIT) or Magnetic Induction Tomography(MIT). A circular subject with embedded circular objects is segmented into equal width slices from different angles. For each angle, Conductance and Conductivity of each slice is calculated and stored in an array. A back projection method is used to generate a two-dimensional image from one-dimensional projections. As a back projection method, Inverse Radon Transformation is applied on the calculated conductance and conductivity to reconstruct two dimensional images. These images are compared to the target image. In the time of image reconstruction, different filters are used and these images are compared with each other and target image.
Online Paper Submission - 6th International Conference on Machine Learning & ...ijistjournal
6th International Conference on Machine Learning & Applications (CMLA 2024) will provide an excellent international forum for sharing knowledge and results in theory, methodology and applications of on Machine Learning & Applications.
Authors are solicited to contribute to the conference by submitting articles that illustrate research results, projects, surveying works and industrial experiences that describe significant advances in the following areas, but are not limited to.
Submit Your Research Articles - International Journal of Information Sciences...ijistjournal
The International Journal of Information Science & Techniques (IJIST) focuses on information systems science and technology coercing multitude applications of information systems in business administration, social science, biosciences, and humanities education, library sciences management, depiction of data and structural illustration, big data analytics, information economics in real engineering and scientific problems.
This journal provides a forum that impacts the development of engineering, education, technology management, information theories and application validation. It also acts as a path to exchange novel and innovative ideas about Information systems science and technology.
BER Performance of MPSK and MQAM in 2x2 Almouti MIMO Systemsijistjournal
Almouti published the error performance of the 2x2 space-time transmit diversity scheme using BPSK. One of the key techniques employed for correcting such errors is the Quadrature amplitude modulation (QAM) because of its efficiency in power and bandwidth.. In this paper we explore the error performance of the 2x2 MIMO system using the Almouti space-time codes for higher order PSK and M-ary QAM. MATLAB was used to simulate the system; assuming slow fading Rayleigh channel and additive white Gaussian noise. The simulated performance curves were compared and evaluated with theoretical curves obtained using BER tool on the MATLAB by setting parameters for random generators. The results shows that the technique used do find a place in correcting error rates of QAM system of higher modulation schemes. The model can equally be used not only for the criteria of adaptive modulation but for a platform to design other modulation systems as well.
Online Paper Submission - International Journal of Information Sciences and T...ijistjournal
The International Journal of Information Science & Techniques (IJIST) focuses on information systems science and technology coercing multitude applications of information systems in business administration, social science, biosciences, and humanities education, library sciences management, depiction of data and structural illustration, big data analytics, information economics in real engineering and scientific problems.
This journal provides a forum that impacts the development of engineering, education, technology management, information theories and application validation. It also acts as a path to exchange novel and innovative ideas about Information systems science and technology.
Call for Papers - International Journal of Information Sciences and Technique...ijistjournal
The International Journal of Information Science & Techniques (IJIST) focuses on information systems science and technology coercing multitude applications of information systems in business administration, social science, biosciences, and humanities education, library sciences management, depiction of data and structural illustration, big data analytics, information economics in real engineering and scientific problems.
This journal provides a forum that impacts the development of engineering, education, technology management, information theories and application validation. It also acts as a path to exchange novel and innovative ideas about Information systems science and technology.
International Journal of Information Sciences and Techniques (IJIST)ijistjournal
The International Journal of Information Science & Techniques (IJIST) focuses on information systems science and technology coercing multitude applications of information systems in business administration, social science, biosciences, and humanities education, library sciences management, depiction of data and structural illustration, big data analytics, information economics in real engineering and scientific problems.
This journal provides a forum that impacts the development of engineering, education, technology management, information theories and application validation. It also acts as a path to exchange novel and innovative ideas about Information systems science and technology.
BRAIN TUMOR MRIIMAGE CLASSIFICATION WITH FEATURE SELECTION AND EXTRACTION USI...ijistjournal
Feature extraction is a method of capturing visual content of an image. The feature extraction is the process to represent raw image in its reduced form to facilitate decision making such as pattern classification. We have tried to address the problem of classification MRI brain images by creating a robust and more accurate classifier which can act as an expert assistant to medical practitioners. The objective of this paper is to present a novel method of feature selection and extraction. This approach combines the Intensity, Texture, shape based features and classifies the tumor as white matter, Gray matter, CSF, abnormal and normal area. The experiment is performed on 140 tumor contained brain MR images from the Internet Brain Segmentation Repository. The proposed technique has been carried out over a larger database as compare to any previous work and is more robust and effective. PCA and Linear Discriminant Analysis (LDA) were applied on the training sets. The Support Vector Machine (SVM) classifier served as a comparison of nonlinear techniques Vs linear ones. PCA and LDA methods are used to reduce the number of features used. The feature selection using the proposed technique is more beneficial as it analyses the data according to grouping class variable and gives reduced feature set with high classification accuracy.
Research Article Submission - International Journal of Information Sciences a...ijistjournal
The International Journal of Information Science & Techniques (IJIST) focuses on information systems science and technology coercing multitude applications of information systems in business administration, social science, biosciences, and humanities education, library sciences management, depiction of data and structural illustration, big data analytics, information economics in real engineering and scientific problems.
This journal provides a forum that impacts the development of engineering, education, technology management, information theories and application validation. It also acts as a path to exchange novel and innovative ideas about Information systems science and technology.
A MEDIAN BASED DIRECTIONAL CASCADED WITH MASK FILTER FOR REMOVAL OF RVINijistjournal
In this paper A Median Based Directional Cascaded with Mask (MBDCM) filter has been proposed, which is based on three different sized cascaded filtering windows. The differences between the current pixel and its neighbors aligned with four main directions are considered for impulse detection. A direction index is used for each edge aligned with a given direction. Minimum of these four direction indexes is used for impulse detection under each masking window. Depending on the minimum direction indexes among these three windows new value to substitute the noisy pixel is calculated. Extensive simulations showed that the MBDCM filter provides good performances of suppressing impulses from both gray level and colored benchmarked images corrupted with low noise level as well as for highly dense impulses. MBDCM filter gives better results than MDWCMM filter in suppressing impulses from highly corrupted digital images.
DECEPTION AND RACISM IN THE TUSKEGEE SYPHILIS STUDYijistjournal
During the twentieth century (1932-1972), white physicians representing the United States government
conducted a human experiment known as the Tuskegee Syphilis Study on black syphilis patients in Macon
County, Alabama. The creators of the study, who supported the idea of black inferiority and the concept
that black people’s bodies functioned differently from white people’s, observed the effects of a disease
called syphilis on untreated black patients in order to collect data for further research on syphilis. Black
individuals involved with the study believed that they were receiving treatment, although in truth,
treatments for syphilis were purposely held back from them. Not only this, but fluids from their bodies, such
as blood and spinal fluid, were extracted to serve as research material without their awareness of the
purpose of the collection. The physicians justified their approach by positioning it as mere observation,
asserting that they were not actively intervening with the patients participating in the experiment. However,
despite their claims of passivity, these white physicians engaged in various morally improper actions,
including deceit, which ultimately resulted in the deaths of numerous black patients who might have had a
chance at survival.
Online Paper Submission - International Journal of Information Sciences and T...ijistjournal
The International Journal of Information Science & Techniques (IJIST) focuses on information systems science and technology coercing multitude applications of information systems in business administration, social science, biosciences, and humanities education, library sciences management, depiction of data and structural illustration, big data analytics, information economics in real engineering and scientific problems.
This journal provides a forum that impacts the development of engineering, education, technology management, information theories and application validation. It also acts as a path to exchange novel and innovative ideas about Information systems science and technology.
A NOVEL APPROACH FOR SEGMENTATION OF SECTOR SCAN SONAR IMAGES USING ADAPTIVE ...ijistjournal
The SAR and SAS images are perturbed by a multiplicative noise called speckle, due to the coherent nature of the scattering phenomenon. If the background of an image is uneven, the fixed thresholding technique is not suitable to segment an image using adaptive thresholding method. In this paper a new Adaptive thresholding method is proposed to reduce the speckle noise, preserving the structural features and textural information of Sector Scan SONAR (Sound Navigation and Ranging) images. Due to the massive proliferation of SONAR images, the proposed method is very appealing in under water environment applications. In fact it is a pre- treatment required in any SONAR images analysis system. The results obtained from the proposed method were compared quantitatively and qualitatively with the results obtained from the other speckle reduction techniques and demonstrate its higher performance for speckle reduction in the SONAR images.
Water scarcity is the lack of fresh water resources to meet the standard water demand. There are two type of water scarcity. One is physical. The other is economic water scarcity.
Cosmetic shop management system project report.pdfKamal Acharya
Buying new cosmetic products is difficult. It can even be scary for those who have sensitive skin and are prone to skin trouble. The information needed to alleviate this problem is on the back of each product, but it's thought to interpret those ingredient lists unless you have a background in chemistry.
Instead of buying and hoping for the best, we can use data science to help us predict which products may be good fits for us. It includes various function programs to do the above mentioned tasks.
Data file handling has been effectively used in the program.
The automated cosmetic shop management system should deal with the automation of general workflow and administration process of the shop. The main processes of the system focus on customer's request where the system is able to search the most appropriate products and deliver it to the customers. It should help the employees to quickly identify the list of cosmetic product that have reached the minimum quantity and also keep a track of expired date for each cosmetic product. It should help the employees to find the rack number in which the product is placed.It is also Faster and more efficient way.
Hierarchical Digital Twin of a Naval Power SystemKerry Sado
A hierarchical digital twin of a Naval DC power system has been developed and experimentally verified. Similar to other state-of-the-art digital twins, this technology creates a digital replica of the physical system executed in real-time or faster, which can modify hardware controls. However, its advantage stems from distributing computational efforts by utilizing a hierarchical structure composed of lower-level digital twin blocks and a higher-level system digital twin. Each digital twin block is associated with a physical subsystem of the hardware and communicates with a singular system digital twin, which creates a system-level response. By extracting information from each level of the hierarchy, power system controls of the hardware were reconfigured autonomously. This hierarchical digital twin development offers several advantages over other digital twins, particularly in the field of naval power systems. The hierarchical structure allows for greater computational efficiency and scalability while the ability to autonomously reconfigure hardware controls offers increased flexibility and responsiveness. The hierarchical decomposition and models utilized were well aligned with the physical twin, as indicated by the maximum deviations between the developed digital twin hierarchy and the hardware.
Hybrid optimization of pumped hydro system and solar- Engr. Abdul-Azeez.pdffxintegritypublishin
Advancements in technology unveil a myriad of electrical and electronic breakthroughs geared towards efficiently harnessing limited resources to meet human energy demands. The optimization of hybrid solar PV panels and pumped hydro energy supply systems plays a pivotal role in utilizing natural resources effectively. This initiative not only benefits humanity but also fosters environmental sustainability. The study investigated the design optimization of these hybrid systems, focusing on understanding solar radiation patterns, identifying geographical influences on solar radiation, formulating a mathematical model for system optimization, and determining the optimal configuration of PV panels and pumped hydro storage. Through a comparative analysis approach and eight weeks of data collection, the study addressed key research questions related to solar radiation patterns and optimal system design. The findings highlighted regions with heightened solar radiation levels, showcasing substantial potential for power generation and emphasizing the system's efficiency. Optimizing system design significantly boosted power generation, promoted renewable energy utilization, and enhanced energy storage capacity. The study underscored the benefits of optimizing hybrid solar PV panels and pumped hydro energy supply systems for sustainable energy usage. Optimizing the design of solar PV panels and pumped hydro energy supply systems as examined across diverse climatic conditions in a developing country, not only enhances power generation but also improves the integration of renewable energy sources and boosts energy storage capacities, particularly beneficial for less economically prosperous regions. Additionally, the study provides valuable insights for advancing energy research in economically viable areas. Recommendations included conducting site-specific assessments, utilizing advanced modeling tools, implementing regular maintenance protocols, and enhancing communication among system components.
Immunizing Image Classifiers Against Localized Adversary Attacksgerogepatton
This paper addresses the vulnerability of deep learning models, particularly convolutional neural networks
(CNN)s, to adversarial attacks and presents a proactive training technique designed to counter them. We
introduce a novel volumization algorithm, which transforms 2D images into 3D volumetric representations.
When combined with 3D convolution and deep curriculum learning optimization (CLO), itsignificantly improves
the immunity of models against localized universal attacks by up to 40%. We evaluate our proposed approach
using contemporary CNN architectures and the modified Canadian Institute for Advanced Research (CIFAR-10
and CIFAR-100) and ImageNet Large Scale Visual Recognition Challenge (ILSVRC12) datasets, showcasing
accuracy improvements over previous techniques. The results indicate that the combination of the volumetric
input and curriculum learning holds significant promise for mitigating adversarial attacks without necessitating
adversary training.
NO1 Uk best vashikaran specialist in delhi vashikaran baba near me online vas...Amil Baba Dawood bangali
Contact with Dawood Bhai Just call on +92322-6382012 and we'll help you. We'll solve all your problems within 12 to 24 hours and with 101% guarantee and with astrology systematic. If you want to take any personal or professional advice then also you can call us on +92322-6382012 , ONLINE LOVE PROBLEM & Other all types of Daily Life Problem's.Then CALL or WHATSAPP us on +92322-6382012 and Get all these problems solutions here by Amil Baba DAWOOD BANGALI
#vashikaranspecialist #astrologer #palmistry #amliyaat #taweez #manpasandshadi #horoscope #spiritual #lovelife #lovespell #marriagespell#aamilbabainpakistan #amilbabainkarachi #powerfullblackmagicspell #kalajadumantarspecialist #realamilbaba #AmilbabainPakistan #astrologerincanada #astrologerindubai #lovespellsmaster #kalajaduspecialist #lovespellsthatwork #aamilbabainlahore#blackmagicformarriage #aamilbaba #kalajadu #kalailam #taweez #wazifaexpert #jadumantar #vashikaranspecialist #astrologer #palmistry #amliyaat #taweez #manpasandshadi #horoscope #spiritual #lovelife #lovespell #marriagespell#aamilbabainpakistan #amilbabainkarachi #powerfullblackmagicspell #kalajadumantarspecialist #realamilbaba #AmilbabainPakistan #astrologerincanada #astrologerindubai #lovespellsmaster #kalajaduspecialist #lovespellsthatwork #aamilbabainlahore #blackmagicforlove #blackmagicformarriage #aamilbaba #kalajadu #kalailam #taweez #wazifaexpert #jadumantar #vashikaranspecialist #astrologer #palmistry #amliyaat #taweez #manpasandshadi #horoscope #spiritual #lovelife #lovespell #marriagespell#aamilbabainpakistan #amilbabainkarachi #powerfullblackmagicspell #kalajadumantarspecialist #realamilbaba #AmilbabainPakistan #astrologerincanada #astrologerindubai #lovespellsmaster #kalajaduspecialist #lovespellsthatwork #aamilbabainlahore #Amilbabainuk #amilbabainspain #amilbabaindubai #Amilbabainnorway #amilbabainkrachi #amilbabainlahore #amilbabaingujranwalan #amilbabainislamabad
Welcome to WIPAC Monthly the magazine brought to you by the LinkedIn Group Water Industry Process Automation & Control.
In this month's edition, along with this month's industry news to celebrate the 13 years since the group was created we have articles including
A case study of the used of Advanced Process Control at the Wastewater Treatment works at Lleida in Spain
A look back on an article on smart wastewater networks in order to see how the industry has measured up in the interim around the adoption of Digital Transformation in the Water Industry.
Water Industry Process Automation and Control Monthly - May 2024.pdf
BER Performance of MPSK and MQAM in 2x2 Almouti MIMO Systems
1. International Journal of Information Sciences and Techniques (IJIST) Vol.2, No.5, September 2012
DOI : 10.5121/ijist.2012.2501 1
BER Performance of MPSK and MQAM in 2x2
Almouti MIMO Systems
A. S. Mindaudu1
and A. M. Miyim2
1
Department of Electrical Engineering, Sokoto State Polytechnic, Nigeria.
amindaudu@yahoo.com
2
Department of Electrical, Electronics & Systems Engineering, Faculty of Engineering,
Universiti Kebangsaan Malaysia
ammiyim@eng.ukm.my
ABSTRACT
Almouti published the error performance of the 2x2 space-time transmit diversity scheme using BPSK. One
of the key techniques employed for correcting such errors is the Quadrature amplitude modulation (QAM)
because of its efficiency in power and bandwidth.. In this paper we explore the error performance of the
2x2 MIMO system using the Almouti space-time codes for higher order PSK and M-ary QAM. MATLAB
was used to simulate the system; assuming slow fading Rayleigh channel and additive white Gaussian
noise. The simulated performance curves were compared and evaluated with theoretical curves obtained
using BER tool on the MATLAB by setting parameters for random generators. The results shows that the
technique used do find a place in correcting error rates of QAM system of higher modulation schemes. The
model can equally be used not only for the criteria of adaptive modulation but for a platform to design
other modulation systems as well.
KEYWORDS
MIMO; M-ary QAM; M-ary PSK; Eb/No; BER; STBC
1. INTRODUCTION
The increasing demand for modern communication systems to provide high speed multimedia
wireless services places very stringent requirements on the systems. The communication systems
process message symbols in digital manner with the sole objective of transmitting the symbols
and recovering them correctly at the receiving end. This is not entirely an easy process especially
in wireless systems where several factors come into play. For instance, limitations in bandwidth,
propagation loss, time variance, noise, interference, and multipath fading, among other factors,
make the wireless channel a narrow pipe through which data transmission is not very easy [1].
Wireless systems based on the MIMO technique are employed in applications that require high
data rates. In such systems due to the additional antennas and signal processing chains, power
problems are attendant issues to be resolved. Consequently, choice of modulation schemes and
low power consumption amplifiers are critical in the MIMO systems. This is in addition to the
limitation of the antenna size especially for mobile hand held devices. Coding methods and the
complexity of the receivers are equally important as they impact directly on the realisation of the
expected benefits of the MIMO technique in a commercial manner.
2. International Journal of Information Sciences and Techniques (IJIST) Vol.2, No.5, September 2012
2
MIMO has become an interesting area of research simply as a result of its potential to give many
orders of magnitude improvement in wireless communication performance at no cost of extra
spectrum (only hardware and complexity are added) [2].
2. THE MIMO SIGNAL MODEL
In a MIMO system where there are M transmit and N receive antennas as shown in fig. 1, the
transmitted data signals pass through multiple paths to get to the receiving antennas. Though not
shown on the diagram, but there is also noise that interferes with the data signals along the paths.
Figure 1 Basic M-transmit by N-receive MIMO system
If the channel matrix is H, then the MIMO signal model is defined in matrix form by [2] as
(1)
where
r is the received signal vector
s is the transmitted signal vector
n is the additive white Gaussian noise vector with zero mean and a variance of σ2
.
Equation 1 can also be presented as a system of linear equations given by:-
(2)
For a 2x2 MIMO system, the expression reduces to
3. THE ALMOUTI 2X2 MIMO SCHEME
The encoding and transmission sequence for the two transmit antennas in the Almouti scheme is
shown in Table 1 [3].
3. International Journal of Information Sciences and Techniques (IJIST) Vol.2, No.5, September 2012
3
Table 1 – Encoding and transmission sequence for the Almouti two transmit antennas.
At time t, S1 and S2 are transmitted simultaneously by antennas 1 and 2 respectively. In the next
time instant, t + T where T is the symbol duration -S2
*
and S1
*
are transmitted simultaneously by
antennas 1 and 2 respectively, where * denotes complex conjugation.
A generalised frame design for the scheme requires a concatenation of 2x2 blocks of the space-
time code is as follows:
Given that the channel coefficients remain constant over two consecutive symbol periods, the
signals at the two receive antennas are given by a set of linear equations as follows:-
At time t1,
(3)
(4)
And at time t1+T,
(5)
(6)
where, , , and are complex samples of independent Gaussian distributed noise and
interference.
Antenna 1 Antenna 2
Time t S1 S2
Time t + T -S2
*
S1
*
Space
Time
4. International Journal of Information Sciences and Techniques (IJIST) Vol.2, No.5, September 2012
4
Figure 2. BER performance comparison of coherent BPSK with MRRC and two-branch transmit
diversity in Rayleigh fading. (Source: Almouti, 1998)
The performance of communication systems is, to a large extent, dependent on the type and
efficiency of modulation techniques employed. The published performance of Almouti 2x2
MIMO scheme (fig. 2) employed coherent BPSK which uses only real components of the signal
constellation in the simulation [3]. If the simulation is carried out using QPSK where both real
and imaginary components of the constellation are used, what will the BER performance be?
Quite a number of performance results have been reported for different antenna constellations,
different environmental conditions, different modulation techniques and a lot more scenarios. For
instance, [4] has reported that mutual coupling between antenna elements in a MIMO antenna
constellation could be either positive or negative on the error performance of the Almouti scheme. [5]
simulated the Almouti STBC in MPSK with increasing number of receiving antennas, and concluded that
in Rayleigh fading channels, if the number of receiving antennas is kept constant the performance of STBC
improves with increasing number of transmit antennas.
4. SIMULATION OF 2X2 ALMOUTI MIMO SCHEME
Various MIMO simulation results carried out using MATLAB or C++ with different parameters
both in baseband and pass band have been reported in several papers. The methods used for the
simulation are very diverse in the choice of the parameters for, say, modulation technique, signal
detection, channel model etc. The simulations vary also as a result of the assumptions made in
carrying them out.
After setting some parameters such length of symbols, modulation order, simulating the Almouti
2x2 starts with the transmit side where random data is generated as an input information to the
system. This data is in the form of 1s and 0s randomly generated with equal probability of
occurrence. This data is then split into two, giving rise to data1 and data2 which are fed to a
baseband modulator (MPSK or MQAM) from where the symbols S1 and S2 are produced. These
symbols are then encoded using the Almouti space-time coding scheme generating the code word
given by
5. International Journal of Information Sciences and Techniques (IJIST) Vol.2, No.5, September 2012
5
It is usually necessary, when simulating any system, to have a reference with which to compare
and confirm the veracity of the obtained results. As the simulation is for 2x2 system using the
Almouti Space Time codes, slow fading Rayleigh channel was assumed in line with the
assumptions of [3]. So the encoded Almouti code word is then passed through a simulated
Rayleigh slow fading channel perturbed by complex Gaussian noise factors of zero mean and a
variance of σ2
.
It is pertinent to note that, as the channels are randomly generated and assumed known at the
receiver, channel estimation is not implemented in the simulation. The received signals which are
affected by noise are combined together using equations (7) and (8) to produce outputs C1 and C2
which are then demodulated in the detector.
(7)
(8)
5. SIMULATION RESULTS AND ANALYSIS
The performance curves obtained with MPSK are shown in fig 3.
0 2 4 6 8 10 12 14 16 18 20
10
-7
10
-6
10
-5
10
-4
10
-3
10
-2
10
-1
10
0
10
1
Performance of Almouti 2X2 MIMO system using M-ary PSK
EbNo(dB)
B
E
R
BPSK
QPSK
8-PSK
16-PSK
32-PSK
64-PSK
Figure 3. Performance curves of Almouti 2x2 MIMO scheme using M-ary PSK
The results show that as the modulation order increases more energy is needed to achieve a given
error probability. Increase in the modulation order means an increase in the number of bits per
symbol to be processed. For instance, it can be seen that for a BER of 10-2
almost additional 4dB
of energy is required for QPSK over what will be needed with BPSK. Generally we see from the
curves in Figure 3 that for the same bit error rate of 10-2
, going from M = 4 to M = 8 will require
about 5.8dB, and from M = 8 to M = 16 about 6dB to achieve the same performance.
6. International Journal of Information Sciences and Techniques (IJIST) Vol.2, No.5, September 2012
6
Figure 4. Performance of Almouti 2x2 MIMO system using M-ary QAM
The performance curves obtained with QAM are shown in fig 4. The curves obtained for the M-
ary QAM also show adherence to the expected behaviour for such modulation scheme. It can
however be seen that in comparison to the M-ary PSK curves of fig. 3, while 4QAM is exactly
the same as QPSK in performance, there is a distinct difference in the performance of the higher
order schemes between both QAM and PSK generally. For instance, we see from fig.3 that, a
BER of 10-3
is obtained at Eb/No of about 11dB for QPSK which is the same for 4QAM in fig. 4.
However, if we look at say 16PSK and 16QAM, we find that to achieve a BER of 10-2
will
require about 3.4dB less when using 16QAM than what will be required for 16PSK (which is
approximately 18.6 dB).
Fig. 5 shows more closely the direct comparison between the performance of the simulated
system using PSK and QAM with modulation order of 16. Here we see that 16QAM is more
power efficient than 16PSK and this is attributable to the nature of the signal space diagrams of
the two modulation schemes. Even though QAM and PSK both have 2 – dimensional signal
spaces, the signal points, in the case of PSK, lie on a circle of fixed radius, , where is the
energy per symbol. So, as the modulation order increases, the signal points tend to be more and
more crowded together thereby increasing the probability of error. However, for QAM the signal
points are distributed in the signal space without being confined to lie on a circle.
0 2 4 6 8 10 12 14 16 18 20
10
-7
10
-6
10
-5
10
-4
10
-3
10
-2
10
-1
10
0
10
1
Performance of Almouti 2X2 MIMO system using M-ary QAM
EbNo(dB)
B
E
R
4-QAM
8-QAM
16-QAM
32-QAM
64-QAM
7. International Journal of Information Sciences and Techniques (IJIST) Vol.2, No.5, September 2012
7
0 2 4 6 8 10 12 14 16 18 20
10
-4
10
-3
10
-2
10
-1
10
0
10
1
Performance Comparison of Almouti 2X2 MIMO with P = 16
EbNo(dB)
BER
16-PSK
16-QAM
Figure 5. Performance comparison of Almouti 2x2 MIMO with 16-PSK and 16-QAM
While BPSK is better than QPSK and 16QAM (fig 6) in terms of power usage (i.e. lower EbNo
for a given BER), its data rate is lower. In fig. 6 we see that 16QAM which is more susceptible to
noise and interference due to its dependence on amplitude requires relatively more power for a
given BER, but it should be noted that it has a higher spectral efficiency when compared with
BPSK or QPSK [6].
0 2 4 6 8 10 12 14 16 18 20
10
-7
10
-6
10
-5
10
-4
10
-3
10
-2
10
-1
10
0
Performance Comparison of Almouti 2X2 MIMO system
EbNo(dB)
BER
BPSK
QPSK
16QAM
Figure 6. Performance comparison of Almouti 2x2 MIMO system with BPSK, QPSK and
16-QAM
We see from Fig. 7 that there is just about 1dB additional energy required in the simulated result
to achieve the same error performance as the theoretical curve. However, for the 16QAM and
64QAM, the energy required for a given error is much more as can be seen in Figs. 8 and 9. For a
given error probability of 10-1
, for instance, the energy required in the simulated curve shows the
need for approximately 7dB above the theoretical requirement in the case of 16QAM. But, with
8. International Journal of Information Sciences and Techniques (IJIST) Vol.2, No.5, September 2012
8
64QAM, almost twice that amount of energy is necessary to achieve the same level of
performance with the theoretical result.
0 2 4 6 8 10 12 14 16 18 20
10
-7
10
-6
10
-5
10
-4
10
-3
10
-2
10
-1
10
0
Comparison of QPSK performance; diversity order 4
EbNo(dB)
B
E
R
Simulated QPSK
Theoretical QPSK
Figure 7. Performance of simulated vs theoretical MIMO scheme with diversity order 4
in Rayleigh slow fading (QPSK).
0 2 4 6 8 10 12 14 16 18 20
10
-6
10
-5
10
-4
10
-3
10
-2
10
-1
10
0
Comparison of 16-QAM performance; diversity order 4
EbNo(dB)
BER
Simulated 16QAM
Theoretical16QAM
Figure 8. Performance of simulated vs theoretical MIMO scheme with diversity order 4
in Rayleigh slow fading (16QAM).
9. International Journal of Information Sciences and Techniques (IJIST) Vol.2, No.5, September 2012
9
0 2 4 6 8 10 12 14 16 18 20
10
-4
10
-3
10
-2
10
-1
10
0
10
1
Comparison of 64-QAM performance; diversity order 4
EbNo(dB)
BER
Simulated 64QAM
Theoretical 64QAM
Figure 9. Performance of simulated vs theoretical MIMO scheme with diversity order 4
in Rayleigh slow fading (64QAM).
6. CONCLUSION
The Almouti 2x2 MIMO scheme was simulated using both M-ary PSK and M-ary QAM so as to
be able to compare the performance. Using the BER tool on the MATLAB, theoretical
performance curves for the two chosen modulation schemes were obtained and compared with
simulated results. Basic assumptions were made in line with the published work of [3] in
simulating the 2x2 system using PSK.. Generally, the curves obtained in the simulations follow
the expected behaviour for such modulation schemes.
While we can conclude that QPSK outperforms 16QAM in error performance as could be seen in
Fig.6, it is to be noted that QPSK gives only half the data rate possible with 16QAM. So there has
to be a trade-off; get better error performance for less data rate or get more data rate at the
expense of degraded error performance.
The 2x2 MIMO systems was simulated in Rayleigh slow fading and with channel perfectly
assumed to be known at the receiver. Consequently, further simulation could be suggested where
the channel is assumed to be unknown at the receiver, but to be extracted through the received
signal. This will then involve channel estimation at the receiver, and furthermore maximum
likelihood detection could be employed. These simulations could be done in different modulation
schemes and different constellation orders.
For simulations with higher order modulations, the maximum likelihood decoder will be very
complex if there are many antennas. And it was noted that one of the advantages of the Almouti
scheme is its simple structure and linear processing at the receiver for two transmit antennas.
Furthermore, it is not known yet whether for general complex constellations the Almouti space-
time code and the simple linear processing will give the maximum diversity gain when the
number of transmit antennas is more than two and this could be another area for future research.
10. International Journal of Information Sciences and Techniques (IJIST) Vol.2, No.5, September 2012
10
REFERENCES
[1] Tarokh V, Naguib A, Seshadri N and Calderbank,A. R, (1999)’ Combined Array Processing and
Space–Time Coding’ IEEE Transactions on Information Theory, vol. 45, no. 4
[2] Gesbert D, Shafi M, Shiu D, Smith P J, and Naguib A, (2003)’ From Theory to Practice: An
Overview of MIMO Space–Time Coded Wireless Systems’ IEEE Journal on Selected Areas in
Communications, vol. 21, no. 3: 281-302.
[3] Almouti S. M. (1998) ‘A Simple Transmit Diversity Technique for Wireless Communications’ IEE
Journal on Select Areas in Communications, vol. 16 no. 8: 1451-1458
[4] Abouda, A. A., El-Sallabi, H.M. and Häggman, S.G.,(2006) ‘Effect of Mutual Coupling on BER
Performance of Almouti Scheme,’ Proc. of IEEE International Symposium on Antennas and
Propagation, AP-S 2006, pp. 4797-4800, Jul. 2006, New Mexico, USA.
[5] Yuyu, L. and Yongzhi, L (2007) ‘Research and Performance Analysis of Space-Time Block Codes in
MIMO system’ IEEE International Conference on Wireless Communications, Networking and Mobile
Computing, 2007. WiCom 2007, pp. 118-121
[6] Pearson, J., (1992) ‘Basic Communication Theory’ Prentice Hall International (UK) Ltd.
[7] Schindler, S. (2006) Introduction to MIMO Systems, Application Note 1MA102, Rhode&Schwarz,
http://www.mwjournal.cm/BGDownload/MIMO.pdf accessed: on 6th August 2008.
[8] Shafi, M., Gesbert, D., Shiu, D., Smith, P. J. and Tranter W. H. (2003) ‘Guest Editorial MIMO
Systems and Applications: Part I’ IEEE Journal on Selected Areas in Communications, vol. 21, no. 3.
[9] Proakis J. G. (1995) Digital Communications, 3rd
Edition McGraw Hill Book Co., Singapore
[10] Calhoun G. M. (2003) Third Generation Wireless Systems Artech House, Inc., Norwood MA, USA.
[11] Almers P., Bonek E., Burr A., Czink N., Debbah M., Degli-Esposti V., Hofstetter H, Kyösti P,
Laurenson D, Matz G. Molisch A F, Oestges C, and Özcelik H, (2007)’ Survey of Channel and Radio
Propagation Models for Wireless MIMO Systems’ EURASIP Journal on Wireless Communications
and Networking vol. 2007, Article ID 19070, p 19 doi:10.1155/2007/19070
[12] Abu-Rgheff M. A. (2007) Introduction to CDMA Wireless Communications Elsevier Ltd, Oxford,
UK.
[13] J. Jialitto, M. Stege, M. Lohning, M. Bronzel and G. Fettweis, “A vector Channel Model with
Stochastic Fading Simulation, In PIMRC’99, Osaka Japan, September 1999
[14] Ernst Borek, et al, “A Geometry-Based Stochastic MIMO Channel Model for 4G Indoor Broadband
Packet Access”, XXVIIIth General Assembly of International Union of Radio Science (URSI), New
Delhi, India 23rd
October, 2005
Authors
A.S. Mindaudu obtained his diploma in Electrical/Electronic Engineering from Kaduna Polytechnic, BSc
in Electrical/ Electronics Engineering from Ahmadu Bello University both in Nigeria. He then proceeded to
University of Plymouth, UK and obtained an MSc in Communication Engineering. He was a Lecturer at the
Kaduna Polytechnic before joining a telecommunication Company where he raised to the position of
Deputy General Manager Network Planning and later Projects. He is presently pursuing his PhD at Usman
Danfodio University, Nigeria.
A. M.Miyim obtained his diploma in Electronic/Communication Engineering from Kaduna Polytechnic,
Nigeria and an MSC in Communication Engineering from Odessa National Academy of
Telecommunications (ONAT), Ukraine. He was a Lecturer at the Kaduna Polytechnic and Abubakar
Tafawa Balewa University bauchi(ATBU), Nigeria before joining a telecommunication Company where he
handled the CDMA Network Expansion Project. He is presently pursuing his PhD at the Universiti
Kebangsaan, (UKM), Malaysia. His interest is in Algorithm Development, Wireless Network and 4G.