This document summarizes an article that optimizes the Okumura-Hata propagation model for 800MHz radio frequency in Yaounde, Cameroon using a Newton second order iterative algorithm. Radio measurements were collected through drive tests on an existing CDMA2000 network in Yaounde. The root mean squared error between predicted and measured values was calculated to validate the optimized model. A new model developed through this process was found to better represent the local environment compared to the standard Okumura-Hata model. The optimized model can be used for future radio network planning in Yaounde, such as for upcoming LTE deployment in the 800MHz band.
Development of an adaptive and a switched beammarwaeng
This document discusses the development of two smart antenna systems for wireless communications - an adaptive system and a switched beam system. The switched beam system uses Butler matrix beamforming networks to direct beams in both azimuth and elevation. The adaptive system uses vector modulators for adaptive beamforming in azimuth and Butler matrices for switched beams in elevation. Both systems were designed, simulated, and tested at 2.45GHz. Simulation results showed the adaptive system improved sidelobe levels and ability to steer beams compared to the switched beam system, though it has increased complexity. The switched beam system offers simpler and lower cost operation while maintaining good beamforming performance.
This document is a thesis submitted by Mohammed Abuibaid to Kocaeli University regarding adaptive beam-forming. It discusses various beam-forming techniques including switched array antennas, DSP-based phase manipulation, and beamforming by precoding. It also covers adaptive beamforming algorithms such as LMS, NLMS, RLS, and CM. Various beam patterns generated by these algorithms are presented. The document motivates the need for adaptive beamforming and 3D beamforming to improve energy efficiency in wireless networks.
3D METALLIC PLATE LENS ANTENNA BASED BEAMSPACE CHANNEL ESTIMATION TECHNIQUE F...ijwmn
Beamspace channel estimation mechanism for massive MIMO (multiple input multiple output) antenna
system presents a major process to compensate the 5G spectrum challenges caused by the proliferation of
information from mobile devices. However, this estimation is required to ensure the perfect channel state
information (CSI) for lower amount of Radio Frequency (RF) chains for each beam. In addition, phase
shifter (PS) components used in this estimation need high power to select the beam in the desired direction.
To overcome these limitations, in this work, we propose Regular Scanning Support Detection (RSSD)
based channel estimation mechanism. Moreover, we utilise a 3D lens antenna array having metallic plate
and a switch in our model which compensates the limitation of phase shifters. Simulation results show that
the proposed RSSD based channel estimation surpasses traditional technique and SD based channel
estimation even in lower SNR area which is highly desirable in the millimeter wave (mmWave) massive
MIMO systems.
The presentation is about Adaptive Beamforming for high data-rate applications. Analog beamforming, which is considered a cost effective solution for consumer devices are investigated. Two adaptive analog beamforming algorithms, i.e., a well-known perturbation-based and dmr-based which overcomes the drawbacks of perturbation-based algorithm are discussed in-detail and their performance comparisons are made with the help of computer simulations. Also variation of single-port structure is considered and it's benefits are exploited with the help of modified analog beamforming algorithms.
Energy Efficiency of MIMO-OFDM Communication SystemIJERA Editor
The document discusses the energy efficiency of MIMO-OFDM communication systems. It begins with an introduction to the need for high-speed communication networks to meet increasing data demands. It then describes how MIMO and OFDM technologies can be combined to enhance data rates over frequency-selective fading channels. The document presents the system model of a MIMO-OFDM system using adaptive beamforming to mitigate co-channel interference at the satellite. Simulation results using MATLAB show that MIMO-OFDM systems have better performance than other modulation schemes in terms of lower bit error rate and mean square error.
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
This document summarizes a research paper that evaluates the performance of different MIMO techniques for MIMO-OFDM systems. It describes spatial multiplexing (SM), space time block coding (STBC), and a hybrid model combining SM and STBC. A simulation model of a 4x4 antenna hybrid MIMO-OFDM system is developed. Results show the hybrid system provides lower bit error rates than SM or STBC systems alone, improving both data rate and link reliability for wireless communication.
Design of area and power efficient half adder using transmission gateeSAT Journals
Abstract This paper gives an idea to reduce power and surface area of half adder circuit using very popular technique i.e. transmission gate. An adder is a digital circuit that performs addition of two numbers. In many computers and other kind of processors, adders are used not only in arithmetic logic unit but also in other parts of the processors where they are used to calculate addresses, table indices and similar operations .in this paper two bit addition has been done using conventional and transmission gate level and power, area and number of transistors are the scope of comparison. According to the simulation result, power and area are reduced by 55.35 % and 40.269% respectively when the circuit is implemented by transmission gate .thus transmission gate has become a very popular and useful technique to implement digital circuits which help to reduce power, surface area as well as number of transistors. Keywords: Transmission gate (TG), Half adder, CMOS logic gates, Surface area, Power.
Development of an adaptive and a switched beammarwaeng
This document discusses the development of two smart antenna systems for wireless communications - an adaptive system and a switched beam system. The switched beam system uses Butler matrix beamforming networks to direct beams in both azimuth and elevation. The adaptive system uses vector modulators for adaptive beamforming in azimuth and Butler matrices for switched beams in elevation. Both systems were designed, simulated, and tested at 2.45GHz. Simulation results showed the adaptive system improved sidelobe levels and ability to steer beams compared to the switched beam system, though it has increased complexity. The switched beam system offers simpler and lower cost operation while maintaining good beamforming performance.
This document is a thesis submitted by Mohammed Abuibaid to Kocaeli University regarding adaptive beam-forming. It discusses various beam-forming techniques including switched array antennas, DSP-based phase manipulation, and beamforming by precoding. It also covers adaptive beamforming algorithms such as LMS, NLMS, RLS, and CM. Various beam patterns generated by these algorithms are presented. The document motivates the need for adaptive beamforming and 3D beamforming to improve energy efficiency in wireless networks.
3D METALLIC PLATE LENS ANTENNA BASED BEAMSPACE CHANNEL ESTIMATION TECHNIQUE F...ijwmn
Beamspace channel estimation mechanism for massive MIMO (multiple input multiple output) antenna
system presents a major process to compensate the 5G spectrum challenges caused by the proliferation of
information from mobile devices. However, this estimation is required to ensure the perfect channel state
information (CSI) for lower amount of Radio Frequency (RF) chains for each beam. In addition, phase
shifter (PS) components used in this estimation need high power to select the beam in the desired direction.
To overcome these limitations, in this work, we propose Regular Scanning Support Detection (RSSD)
based channel estimation mechanism. Moreover, we utilise a 3D lens antenna array having metallic plate
and a switch in our model which compensates the limitation of phase shifters. Simulation results show that
the proposed RSSD based channel estimation surpasses traditional technique and SD based channel
estimation even in lower SNR area which is highly desirable in the millimeter wave (mmWave) massive
MIMO systems.
The presentation is about Adaptive Beamforming for high data-rate applications. Analog beamforming, which is considered a cost effective solution for consumer devices are investigated. Two adaptive analog beamforming algorithms, i.e., a well-known perturbation-based and dmr-based which overcomes the drawbacks of perturbation-based algorithm are discussed in-detail and their performance comparisons are made with the help of computer simulations. Also variation of single-port structure is considered and it's benefits are exploited with the help of modified analog beamforming algorithms.
Energy Efficiency of MIMO-OFDM Communication SystemIJERA Editor
The document discusses the energy efficiency of MIMO-OFDM communication systems. It begins with an introduction to the need for high-speed communication networks to meet increasing data demands. It then describes how MIMO and OFDM technologies can be combined to enhance data rates over frequency-selective fading channels. The document presents the system model of a MIMO-OFDM system using adaptive beamforming to mitigate co-channel interference at the satellite. Simulation results using MATLAB show that MIMO-OFDM systems have better performance than other modulation schemes in terms of lower bit error rate and mean square error.
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
This document summarizes a research paper that evaluates the performance of different MIMO techniques for MIMO-OFDM systems. It describes spatial multiplexing (SM), space time block coding (STBC), and a hybrid model combining SM and STBC. A simulation model of a 4x4 antenna hybrid MIMO-OFDM system is developed. Results show the hybrid system provides lower bit error rates than SM or STBC systems alone, improving both data rate and link reliability for wireless communication.
Design of area and power efficient half adder using transmission gateeSAT Journals
Abstract This paper gives an idea to reduce power and surface area of half adder circuit using very popular technique i.e. transmission gate. An adder is a digital circuit that performs addition of two numbers. In many computers and other kind of processors, adders are used not only in arithmetic logic unit but also in other parts of the processors where they are used to calculate addresses, table indices and similar operations .in this paper two bit addition has been done using conventional and transmission gate level and power, area and number of transistors are the scope of comparison. According to the simulation result, power and area are reduced by 55.35 % and 40.269% respectively when the circuit is implemented by transmission gate .thus transmission gate has become a very popular and useful technique to implement digital circuits which help to reduce power, surface area as well as number of transistors. Keywords: Transmission gate (TG), Half adder, CMOS logic gates, Surface area, Power.
IMPROVEMENT OF LTE DOWNLINK SYSTEM PERFORMANCES USING THE LAGRANGE POLYNOMIAL...IJCNCJournal
The document describes research on improving the performance of LTE downlink systems using Lagrange polynomial interpolation for channel estimation. It presents the MIMO-OFDM transmission scheme used in LTE and discusses various channel estimation techniques including linear, sinus cardinal, Newton polynomial, and Lagrange polynomial interpolation. Simulation results show that Lagrange polynomial interpolation outperforms other methods in terms of block error rate, throughput, and error vector magnitude versus signal-to-noise ratio. The optimal order of the Lagrange polynomial is determined by evaluating performance for different orders.
This document summarizes a research paper on developing a reconfigurable hardware architecture for implementing maximum likelihood (ML) decoding algorithms in MIMO systems. It begins by introducing MIMO techniques for improving wireless communication throughput. It then describes various MIMO receiver algorithms and chooses ML for its best performance. The document outlines the ML decoding algorithm and presents a Simulink model. It discusses implementing the MIMO decoder as a modular, reconfigurable architecture on an FPGA and shows placement results on a Xilinx Virtex 4 chip. The work aims to provide flexible hardware for MIMO signal processing applications.
Performance analysis of adaptive beamforming at receiver side by using lms an...Ijrdt Journal
The Least Mean Squares (LMS) algorithm is an important member of the family of stochastic gradient algorithms. A significant feature of the LMS algorithm is its simplicity. The recursive least squares (RLS) algorithm recursively finds the filter coefficients for minimizing linear least squares cost function. Smart antenna generally refers to any antenna array. Beamforming is a signal processing technique used in sensor arrays for directional signal transmission or reception. This spatial selectivity is achieved by using adaptive or fixed receive/transmit beam patterns. The improvement compared with an omnidirectional reception/transmission is known as the receive/transmit gain (or loss). In this study, fixed weight beamforming basics and maximum signal to interference ratio are given. The theoretical information of adaptive beamforming, LMS (Least Mean Square) and RLS (Recursive Mean Squares) algorithms are explained. Adaptive beamforming in recieve antenna is simulated by using LMS and RLS algorithms. Simulation results are discussed and explained.
This document describes a simulation of an optical orthogonal frequency division multiplexing (OFDM) system using different M-ary quadrature amplitude modulation (QAM) techniques. The performance of the system was evaluated in terms of bit error rate (BER) and signal-to-noise ratio (SNR) by varying the modulation order M to 16, 64, and 256. Simulation results showed that higher modulation orders require higher SNR values to achieve the same BER as lower modulation orders. The simulated results closely matched theoretical predictions, though there was a deviation of 3-3.5 dB, likely due to additional noise and losses not accounted for in the theoretical model.
BER Performance of MPSK and MQAM in 2x2 Almouti MIMO Systemsijistjournal
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
International Journal of Engineering Research and Applications (IJERA) is a team of researchers not publication services or private publications running the journals for monetary benefits, we are association of scientists and academia who focus only on supporting authors who want to publish their work. The articles published in our journal can be accessed online, all the articles will be archived for real time access.
Our journal system primarily aims to bring out the research talent and the works done by sciaentists, academia, engineers, practitioners, scholars, post graduate students of engineering and science. This journal aims to cover the scientific research in a broader sense and not publishing a niche area of research facilitating researchers from various verticals to publish their papers. It is also aimed to provide a platform for the researchers to publish in a shorter of time, enabling them to continue further All articles published are freely available to scientific researchers in the Government agencies,educators and the general public. We are taking serious efforts to promote our journal across the globe in various ways, we are sure that our journal will act as a scientific platform for all researchers to publish their works online.
A transmission line based technique for de-embedding noise parametersvilla1451
This document presents a transmission line-based technique for de-embedding noise parameters of transistors from measured S-parameter data. The technique accounts for the distributed effects of interconnect lines and pad-interconnect discontinuities. It requires only two transmission line test structures to de-embed all devices in a process, making it area-efficient. The technique is validated experimentally on 90nm and 130nm n-MOSFETs and SiGe HBTs. Results are compared to other lumped and distributed de-embedding methods.
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.
BER Performance of Antenna Array-Based Receiver using Multi-user Detection in...ijwmn
1) The document proposes a novel approach to evaluate the average probability of error for a DS-CDMA system using an antenna array receiver. It approximates the angular gain function of the spatial filter as a fixed beamwidth function to partition interferers into in-beam and out-beam groups.
2) It derives an accurate formula for the average bit error rate over Nakagami fading channels. The analysis considers asynchronous transmission and adapts Gaussian approximations to account for noise and multi-user interference after beamforming.
3) Simulation results are provided to validate the research for single antenna systems and show that the proposed model confirms the benefits of adaptive antennas in reducing interference and provides a good approximation of error probability.
1. MIMO (multiple-input multiple-output) communication uses multiple antennas at both the transmitter and receiver to improve performance. It can increase data throughput and link range without additional bandwidth or transmit power.
2. MIMO systems can be modeled as a narrowband channel with n transmit antennas and m receive antennas. The channel is represented by a matrix H. MIMO channels can be decomposed into parallel SISO channels through singular value decomposition to simplify processing.
3. The capacity of MIMO channels is determined through water-filling of the eigenvalues of the channel matrix H. MIMO provides diversity gain through techniques like beamforming and exploiting the diversity-multiplexing tradeoff.
An analtical analysis of w cdma smart antennamarwaeng
The document analyzes the signal-to-interference-noise ratio (SINR) performance of two beamforming methods, complex conjugate (CC) and direction-of-arrival (DOA), used in Wideband Code Division Multiple Access (W-CDMA) smart antenna systems. It derives analytic SINR evaluation equations for both methods under different channel conditions. The results show that the CC and DOA methods provide the same mean SINR performance but the CC method is more robust to channel estimation errors. Simulation results are presented to verify the analytic performance and robustness analyses.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
Analysis of cyclic prefix length effect on ISI limitation in OFDM system over...IJECEIAES
In this work, the influence of the cyclic prefix on the performance of the OFDM system is studied. We worked out an OFDM transceiver using a 16 QAM modulation scheme, a comparison of the BER for various lengths of the cyclic prefix has been achieved, and the influence of the noise introduced in the channel has been highlighted, for both a Gaussian and Rayleigh noise. The simulation was carried out on MATLAB where the curves of the BER for various lengths of the cyclic prefix are given and compared. We also adopted as a metric the QAM constellation to show the dispersion of the carriers as a consequence of the transmission channel, the mitigation of this effect by the CP is noticeable.
IRJET- Performance Analysis of MIMO-OFDM System using Different Antenna Confi...IRJET Journal
This document analyzes the performance of a MIMO-OFDM wireless communication system using different antenna configurations through simulation in MATLAB. It finds that the system performs better when diversity is increased at both the transmitter and receiver sides. Specifically, it shows that bit error rate decreases and signal-to-noise ratio increases as the number of receiving antennas is increased when using BPSK modulation over an AWGN channel. The performance of MIMO-OFDM is evaluated for different detection methods and antenna configurations, and zero-forcing with successive interference cancellation is found to improve bit error rate compared to other techniques.
Sparse channel estimation by pilot allocation in MIMO-OFDM systems IRJET Journal
This document summarizes research on sparse channel estimation techniques for MIMO-OFDM systems using compressed sensing theory. It describes how compressed sensing algorithms like Subspace Pursuit (SP) and CoSaMP can provide better channel estimation performance than conventional techniques like least squares estimation. SP and CoSaMP are greedy algorithms that iteratively select columns from the measurement matrix to minimize mean square error. Simulation results showed these compressed sensing algorithms reduce mean square error and bit error rate compared to normal channel estimation.
Ieee 802.20 working group on mobile broadband wireless accessNguyen Minh Thu
This document discusses inconsistencies in the path loss models recommended for evaluating mobile broadband wireless access (MBWA) proposals for the IEEE 802.20 working group. It proposes additions to clarify the frequency dependence of the path loss models for different environments (macrocell suburban/urban, microcell LOS/NLOS, indoor). Models are provided for path loss as a function of carrier frequency and distance. It recommends adopting the proposed path loss formulations and accounting for carrier frequency and bandwidth when evaluating proposals using different channel models.
Implementation of 8x8 MIMO OFDM systems for higher order modulation using QOS...ijsrd.com
A general Quasi orthogonal space time block code (QOSTBC) structure is proposed for multiple-input multiple-output-orthogonal frequency division multiplexing (MIMO-OFDM) systems for 8 X 8 antenna configuration. The signal detection technology used in this work for MIMO-OFDM system is Zero-Forcing Equalization (linear detection technique). In this paper, analysis of high level of modulations (i.e. M-QAM and M-PSK for different values of M) on MIMO-OFDM system is presented. In this, AWGN, Rayleigh and Rician channels have been used for analysis purpose and their effect on BER and Spectral Efficiency for high data rates have been presented. The proposed system has better performance than the other systems in terms of SNR improvement of 3-5 dB and spectral efficiency.
The document summarizes topics related to massive MIMO and random matrix theory (RMT). It discusses how massive MIMO uses a large number of antennas to focus signal energy into small regions. RMT provides mathematical results for analyzing random matrices arising in wireless communications, such as Gaussian, Wigner, and Wishart matrices. Wireless channel models and capacity formulations are also summarized. The document concludes that RMT is useful for characterizing fundamental limits of wireless channels and converging analysis of very large matrices.
IRJET- Structured Compression Sensing Method for Massive MIMO-OFDM SystemsIRJET Journal
The document presents a structured compression sensing method for massive MIMO-OFDM systems called Priori information-assisted adaptive structured subspace pursuit (PA-ASSP) algorithm. PA-ASSP aims to improve channel estimation accuracy with reduced complexity compared to existing algorithms like adaptive structured subspace pursuit (ASSP). It initializes channel estimation using prior information and exploits common sparsity of MIMO channels across OFDM symbols. Simulation results show PA-ASSP achieves better bit error rate and normalized mean square error performance than ASSP and other algorithms under different SNR levels.
This document discusses the development of a web-based decision support system (DSS) for monitoring and predicting water quality parameters important for outdoor microalgae cultivation. The DSS allows users to monitor temperature and salinity in real-time and predicts future values of these parameters based on historical data using a K-nearest neighbors algorithm. Validation tests found the DSS could accurately forecast temperature and salinity 96.98% and 98.92% of the time respectively. The DSS notifies users when parameter levels rise or fall outside standard ranges and provides suggestions to maintain optimal water quality.
1) The document reviews land acquisition policies and processes used in various countries around the world. It examines studies that analyzed land acquisition practices in countries like India, China, Nigeria, Malaysia, Mozambique, Ghana, Zambia, Tanzania, Bangladesh, and Vietnam.
2) The studies found that compensation provided to land owners for acquisition varied significantly between countries and sometimes within countries. Valuation methods also differed, though market value was commonly used.
3) No single best practice for land acquisition and compensation was identified. The document concludes that developing a transparent framework informed by principles, processes, and mechanisms could help improve compensation systems.
This document describes a proposed method to improve image classification accuracy and speed using the bag-of-features model with spatial pooling. The proposed method has two phases: a training phase to create an image feature database, and an evaluation phase to classify new images. In the evaluation phase, spatial pooling is applied to input image features before classification with KNN. Variance-based feature selection is also used to reduce features before KNN classification. Experimental results show the proposed method improves classification accuracy up to 5% and reduces classification time by up to 50% compared to the standard bag-of-features model.
IMPROVEMENT OF LTE DOWNLINK SYSTEM PERFORMANCES USING THE LAGRANGE POLYNOMIAL...IJCNCJournal
The document describes research on improving the performance of LTE downlink systems using Lagrange polynomial interpolation for channel estimation. It presents the MIMO-OFDM transmission scheme used in LTE and discusses various channel estimation techniques including linear, sinus cardinal, Newton polynomial, and Lagrange polynomial interpolation. Simulation results show that Lagrange polynomial interpolation outperforms other methods in terms of block error rate, throughput, and error vector magnitude versus signal-to-noise ratio. The optimal order of the Lagrange polynomial is determined by evaluating performance for different orders.
This document summarizes a research paper on developing a reconfigurable hardware architecture for implementing maximum likelihood (ML) decoding algorithms in MIMO systems. It begins by introducing MIMO techniques for improving wireless communication throughput. It then describes various MIMO receiver algorithms and chooses ML for its best performance. The document outlines the ML decoding algorithm and presents a Simulink model. It discusses implementing the MIMO decoder as a modular, reconfigurable architecture on an FPGA and shows placement results on a Xilinx Virtex 4 chip. The work aims to provide flexible hardware for MIMO signal processing applications.
Performance analysis of adaptive beamforming at receiver side by using lms an...Ijrdt Journal
The Least Mean Squares (LMS) algorithm is an important member of the family of stochastic gradient algorithms. A significant feature of the LMS algorithm is its simplicity. The recursive least squares (RLS) algorithm recursively finds the filter coefficients for minimizing linear least squares cost function. Smart antenna generally refers to any antenna array. Beamforming is a signal processing technique used in sensor arrays for directional signal transmission or reception. This spatial selectivity is achieved by using adaptive or fixed receive/transmit beam patterns. The improvement compared with an omnidirectional reception/transmission is known as the receive/transmit gain (or loss). In this study, fixed weight beamforming basics and maximum signal to interference ratio are given. The theoretical information of adaptive beamforming, LMS (Least Mean Square) and RLS (Recursive Mean Squares) algorithms are explained. Adaptive beamforming in recieve antenna is simulated by using LMS and RLS algorithms. Simulation results are discussed and explained.
This document describes a simulation of an optical orthogonal frequency division multiplexing (OFDM) system using different M-ary quadrature amplitude modulation (QAM) techniques. The performance of the system was evaluated in terms of bit error rate (BER) and signal-to-noise ratio (SNR) by varying the modulation order M to 16, 64, and 256. Simulation results showed that higher modulation orders require higher SNR values to achieve the same BER as lower modulation orders. The simulated results closely matched theoretical predictions, though there was a deviation of 3-3.5 dB, likely due to additional noise and losses not accounted for in the theoretical model.
BER Performance of MPSK and MQAM in 2x2 Almouti MIMO Systemsijistjournal
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
International Journal of Engineering Research and Applications (IJERA) is a team of researchers not publication services or private publications running the journals for monetary benefits, we are association of scientists and academia who focus only on supporting authors who want to publish their work. The articles published in our journal can be accessed online, all the articles will be archived for real time access.
Our journal system primarily aims to bring out the research talent and the works done by sciaentists, academia, engineers, practitioners, scholars, post graduate students of engineering and science. This journal aims to cover the scientific research in a broader sense and not publishing a niche area of research facilitating researchers from various verticals to publish their papers. It is also aimed to provide a platform for the researchers to publish in a shorter of time, enabling them to continue further All articles published are freely available to scientific researchers in the Government agencies,educators and the general public. We are taking serious efforts to promote our journal across the globe in various ways, we are sure that our journal will act as a scientific platform for all researchers to publish their works online.
A transmission line based technique for de-embedding noise parametersvilla1451
This document presents a transmission line-based technique for de-embedding noise parameters of transistors from measured S-parameter data. The technique accounts for the distributed effects of interconnect lines and pad-interconnect discontinuities. It requires only two transmission line test structures to de-embed all devices in a process, making it area-efficient. The technique is validated experimentally on 90nm and 130nm n-MOSFETs and SiGe HBTs. Results are compared to other lumped and distributed de-embedding methods.
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.
BER Performance of Antenna Array-Based Receiver using Multi-user Detection in...ijwmn
1) The document proposes a novel approach to evaluate the average probability of error for a DS-CDMA system using an antenna array receiver. It approximates the angular gain function of the spatial filter as a fixed beamwidth function to partition interferers into in-beam and out-beam groups.
2) It derives an accurate formula for the average bit error rate over Nakagami fading channels. The analysis considers asynchronous transmission and adapts Gaussian approximations to account for noise and multi-user interference after beamforming.
3) Simulation results are provided to validate the research for single antenna systems and show that the proposed model confirms the benefits of adaptive antennas in reducing interference and provides a good approximation of error probability.
1. MIMO (multiple-input multiple-output) communication uses multiple antennas at both the transmitter and receiver to improve performance. It can increase data throughput and link range without additional bandwidth or transmit power.
2. MIMO systems can be modeled as a narrowband channel with n transmit antennas and m receive antennas. The channel is represented by a matrix H. MIMO channels can be decomposed into parallel SISO channels through singular value decomposition to simplify processing.
3. The capacity of MIMO channels is determined through water-filling of the eigenvalues of the channel matrix H. MIMO provides diversity gain through techniques like beamforming and exploiting the diversity-multiplexing tradeoff.
An analtical analysis of w cdma smart antennamarwaeng
The document analyzes the signal-to-interference-noise ratio (SINR) performance of two beamforming methods, complex conjugate (CC) and direction-of-arrival (DOA), used in Wideband Code Division Multiple Access (W-CDMA) smart antenna systems. It derives analytic SINR evaluation equations for both methods under different channel conditions. The results show that the CC and DOA methods provide the same mean SINR performance but the CC method is more robust to channel estimation errors. Simulation results are presented to verify the analytic performance and robustness analyses.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
Analysis of cyclic prefix length effect on ISI limitation in OFDM system over...IJECEIAES
In this work, the influence of the cyclic prefix on the performance of the OFDM system is studied. We worked out an OFDM transceiver using a 16 QAM modulation scheme, a comparison of the BER for various lengths of the cyclic prefix has been achieved, and the influence of the noise introduced in the channel has been highlighted, for both a Gaussian and Rayleigh noise. The simulation was carried out on MATLAB where the curves of the BER for various lengths of the cyclic prefix are given and compared. We also adopted as a metric the QAM constellation to show the dispersion of the carriers as a consequence of the transmission channel, the mitigation of this effect by the CP is noticeable.
IRJET- Performance Analysis of MIMO-OFDM System using Different Antenna Confi...IRJET Journal
This document analyzes the performance of a MIMO-OFDM wireless communication system using different antenna configurations through simulation in MATLAB. It finds that the system performs better when diversity is increased at both the transmitter and receiver sides. Specifically, it shows that bit error rate decreases and signal-to-noise ratio increases as the number of receiving antennas is increased when using BPSK modulation over an AWGN channel. The performance of MIMO-OFDM is evaluated for different detection methods and antenna configurations, and zero-forcing with successive interference cancellation is found to improve bit error rate compared to other techniques.
Sparse channel estimation by pilot allocation in MIMO-OFDM systems IRJET Journal
This document summarizes research on sparse channel estimation techniques for MIMO-OFDM systems using compressed sensing theory. It describes how compressed sensing algorithms like Subspace Pursuit (SP) and CoSaMP can provide better channel estimation performance than conventional techniques like least squares estimation. SP and CoSaMP are greedy algorithms that iteratively select columns from the measurement matrix to minimize mean square error. Simulation results showed these compressed sensing algorithms reduce mean square error and bit error rate compared to normal channel estimation.
Ieee 802.20 working group on mobile broadband wireless accessNguyen Minh Thu
This document discusses inconsistencies in the path loss models recommended for evaluating mobile broadband wireless access (MBWA) proposals for the IEEE 802.20 working group. It proposes additions to clarify the frequency dependence of the path loss models for different environments (macrocell suburban/urban, microcell LOS/NLOS, indoor). Models are provided for path loss as a function of carrier frequency and distance. It recommends adopting the proposed path loss formulations and accounting for carrier frequency and bandwidth when evaluating proposals using different channel models.
Implementation of 8x8 MIMO OFDM systems for higher order modulation using QOS...ijsrd.com
A general Quasi orthogonal space time block code (QOSTBC) structure is proposed for multiple-input multiple-output-orthogonal frequency division multiplexing (MIMO-OFDM) systems for 8 X 8 antenna configuration. The signal detection technology used in this work for MIMO-OFDM system is Zero-Forcing Equalization (linear detection technique). In this paper, analysis of high level of modulations (i.e. M-QAM and M-PSK for different values of M) on MIMO-OFDM system is presented. In this, AWGN, Rayleigh and Rician channels have been used for analysis purpose and their effect on BER and Spectral Efficiency for high data rates have been presented. The proposed system has better performance than the other systems in terms of SNR improvement of 3-5 dB and spectral efficiency.
The document summarizes topics related to massive MIMO and random matrix theory (RMT). It discusses how massive MIMO uses a large number of antennas to focus signal energy into small regions. RMT provides mathematical results for analyzing random matrices arising in wireless communications, such as Gaussian, Wigner, and Wishart matrices. Wireless channel models and capacity formulations are also summarized. The document concludes that RMT is useful for characterizing fundamental limits of wireless channels and converging analysis of very large matrices.
IRJET- Structured Compression Sensing Method for Massive MIMO-OFDM SystemsIRJET Journal
The document presents a structured compression sensing method for massive MIMO-OFDM systems called Priori information-assisted adaptive structured subspace pursuit (PA-ASSP) algorithm. PA-ASSP aims to improve channel estimation accuracy with reduced complexity compared to existing algorithms like adaptive structured subspace pursuit (ASSP). It initializes channel estimation using prior information and exploits common sparsity of MIMO channels across OFDM symbols. Simulation results show PA-ASSP achieves better bit error rate and normalized mean square error performance than ASSP and other algorithms under different SNR levels.
This document discusses the development of a web-based decision support system (DSS) for monitoring and predicting water quality parameters important for outdoor microalgae cultivation. The DSS allows users to monitor temperature and salinity in real-time and predicts future values of these parameters based on historical data using a K-nearest neighbors algorithm. Validation tests found the DSS could accurately forecast temperature and salinity 96.98% and 98.92% of the time respectively. The DSS notifies users when parameter levels rise or fall outside standard ranges and provides suggestions to maintain optimal water quality.
1) The document reviews land acquisition policies and processes used in various countries around the world. It examines studies that analyzed land acquisition practices in countries like India, China, Nigeria, Malaysia, Mozambique, Ghana, Zambia, Tanzania, Bangladesh, and Vietnam.
2) The studies found that compensation provided to land owners for acquisition varied significantly between countries and sometimes within countries. Valuation methods also differed, though market value was commonly used.
3) No single best practice for land acquisition and compensation was identified. The document concludes that developing a transparent framework informed by principles, processes, and mechanisms could help improve compensation systems.
This document describes a proposed method to improve image classification accuracy and speed using the bag-of-features model with spatial pooling. The proposed method has two phases: a training phase to create an image feature database, and an evaluation phase to classify new images. In the evaluation phase, spatial pooling is applied to input image features before classification with KNN. Variance-based feature selection is also used to reduce features before KNN classification. Experimental results show the proposed method improves classification accuracy up to 5% and reduces classification time by up to 50% compared to the standard bag-of-features model.
This document summarizes a research paper that proposes using sink mobility to maximize the lifetime of wireless sensor networks. The paper introduces wireless sensor networks and describes the existing problem of energy-inefficient routing. It then proposes a solution that involves moving the sink node to different locations to reduce energy consumption. The framework creates alternative paths using AODV routing when nodes have low energy. Results show improved network lifetime, packet delivery ratio, and lower bit error rate compared to stationary sink approaches. Future work may extend the approach to networks with moving sensor nodes.
1. The document examines a local Nigerian game called "tsorry checkerboard" and applies group theory concepts.
2. The game is played on a 2x2 board with each player having up to 3 pieces, and the goal is to line up all three of one's pieces horizontally, vertically, or diagonally.
3. The possible moves of each piece (vertical, horizontal, diagonal, or staying in place) form a Klein four-group, satisfying the group properties of closure, associativity, identity, and inverses. Therefore, group theory can be applied to model the game.
This document discusses the design, analysis, and feasibility testing of a center-mounted suspension system. It begins with an introduction to conventional suspension systems and their limitations. The proposed center-mounted system aims to improve vehicle balance in all terrains by directly attaching the suspension to the vehicle's central chassis. The document then reviews different suspension system types and analyzes the proposed system's working principles and mathematical calculations. Finally, stress analysis using ANSYS software demonstrates the advantages of the center-mounted design in absorbing shocks during turns and on bumpy roads. In conclusion, the proposed system maintains vehicle balance better than conventional designs through its unique center-attached configuration.
This document summarizes a study that used Taguchi methodology to examine the effect of die casting process parameters on porosity levels in aluminum alloy SAE 308. An experiment was conducted using an L9 orthogonal array to test combinations of four process parameters (first phase speed, second phase speed, first phase length, and injection pressure) at three levels. Porosity measurements were taken for each sample and analyzed. ANOVA results showed injection pressure had the greatest effect on porosity levels at 43.64%, followed by first phase length at 28.39%. Predicted porosity levels and a 95% confidence interval were also estimated based on the optimal parameter settings.
The document discusses securing biometric templates when transmitted over non-secure channels by selecting partial fingerprint and iris data, encrypting it using AES with an iris hash as the key, and transmitting the encrypted data. It outlines the need to protect biometric data due to risks of identity theft if templates are compromised. Various attacks on biometric systems and methods of template protection including cryptography and cancelable biometrics are also reviewed.
This document presents a method for image upscaling using a fuzzy ARTMAP neural network. It begins with an introduction to image upscaling and interpolation techniques. It then provides background on ARTMAP neural networks and fuzzy logic. The proposed method uses a linear interpolation algorithm trained with an ARTMAP network. Results show the method performs better than nearest neighbor interpolation in terms of peak signal-to-noise ratio, mean squared error, and structural similarity, though not as high as bicubic interpolation. Overall, the fuzzy ARTMAP network provides an effective way to perform image upscaling with fewer artifacts than traditional methods.
The document studies the microstructure of pure hydroxyapatite (HAp) and a 20% alumina-reinforced HAp bioceramic composite sintered at different temperatures. Scanning electron microscopy revealed that pure HAp sintered at 1250°C had an irregular bubbly surface and well-distributed pores, indicating decomposition. The composite sintered up to 1250°C maintained a dense microstructure with small pores (<3 μm), explaining its higher strength compared to pure HAp. The addition of alumina prevented pore growth at high temperatures, negating the negative effects of HAp decomposition.
The document presents the results of an experimental investigation into the performance of a laboratory screw jack. Various tests were conducted by applying different loads between 450N and 100N to the screw jack. For each load, the mechanical advantage, velocity ratio, and mechanical efficiency were calculated. The results showed that the mechanical efficiency of the screw jack was always less than 50% since the mechanical advantage and velocity ratio were less than half. Frictional forces in the screw and base contributed to the efficiency not remaining constant across different loads.
This document discusses the importance of methodology in scientific research papers that aim to apply science and technology to address millennium challenges. It defines methodology as the framework and methods used in a research study. The document examines key components of methodology, including research design, study population, variables, sampling techniques, sample size determination, data collection methods, and data analysis. It provides examples for how to determine these methodological components and stresses that applying the appropriate methodology is essential for producing valid, high-quality research that can help solve important problems.
This document summarizes research on improving image classification results using neural networks. It compares common image classification methods like support vector machines (SVM) and K-nearest neighbors (KNN). It then evaluates the performance of multilayer perceptron (MLP) neural networks and radial basis function (RBF) neural networks on image classification. The document tests various configurations of MLP and RBF networks on a dataset containing 2310 images across 7 classes. It finds that a MLP network with two hidden layers of 10 neurons each achieves the best results, with an average accuracy of 98.84%. This is significantly higher than the 84.47% average accuracy of RBF networks and outperforms KNN classification as well. The research concludes that neural
This document summarizes a study that analyzed the performance of vertical skirted strip footings on slopes using the finite element software PLAXIS 2D. Various parameters were considered, including the vertical load, depth of footing embedment, distance of footing from crest, ratio of skirt depth to footing width, and configuration of the skirt (one side, both sides, unequal sides). The results showed that skirted foundations significantly improved the bearing capacity compared to unskirted foundations. Bearing capacity increased with deeper skirt depths. Footings at the crest also showed improved bearing capacity. Footing embedment depth did not affect bearing capacity. The study provides insights into using skirted foundations to improve slope stability and bearing capacity
This document discusses different algorithms for task scheduling in cloud computing environments based on various quality of service (QoS) parameters. It summarizes several QoS-based scheduling algorithms including QDA, Improved Cost Based, PAPRIKA, ANT Colony, CMultiQoSSchedule, and SHEFT Workflow. It also provides a comparative table of these algorithms and discusses the various metrics considered by QoS-based scheduling algorithms like time, cost, makespan, trust, and resource utilization. The paper concludes that scheduling is an important factor for cloud environments and that existing algorithms can be improved by considering additional parameters like trust values, execution rates, and success rates.
This document presents a novel malware clustering system based on kernel data structures. It introduces a data-centric malware defense architecture (DMDA) that models and detects malware behavior based on properties of kernel data objects targeted during attacks. The architecture consists of an external monitor that observes a target OS kernel to map dynamic kernel objects and identify memory access patterns specific to malware attacks in order to generate malware signatures and detect and cluster malware. It aims to complement traditional code-centric malware detection approaches by focusing on the manipulation of kernel data.
1) The document presents the results of a stability analysis of a reinforced earth wall for the approach road of a rail over bridge along a national highway.
2) The maximum height of the embankment is 7m, and stability is a concern due to weak subgrade soil. Stability analysis using Slope/W software indicates a factor of safety below recommended values without reinforcement.
3) The addition of geosynthetic reinforcement in the form of geogrids placed at various depths and tensions within the embankment fill improves the factor of safety. The optimum reinforcement configuration is found to be 3 geogrid layers.
This document provides a review of information technology implementation for the educational development of rural India. It discusses several key points:
1) It provides an overview of the Indian education system, including the roles of public and private sectors as well as various supporting institutions.
2) It identifies several problems faced by students in rural areas, such as lack of adequate teachers and infrastructure like classrooms and toilets.
3) It discusses how information and communication technologies (ICT) like computers, internet, mobile phones can help improve quality of education through distance learning programs and training teachers.
4) It outlines several approaches that have been used to promote education in rural India using ICT, including village knowledge centers, e
This document analyzes the performance of the median filter for suppressing impulse noise from images. It applies median filtering to low, medium, and high detail images corrupted with varying densities of salt-and-pepper impulse noise from 1% to 60%. The median filter's performance is evaluated based on its edge-preserving capabilities through edge detection, subjective analysis via visual quality, and objective analysis using mean squared error, peak signal-to-noise ratio, and mean absolute error. The results show that median filtering effectively suppresses low-density impulse noise while preserving edges, though it can blur edges slightly due to uniform filtering and modify some uncorrupted pixels. Overall, the median filter performs better than linear filters for impulse noise removal from
J018127176.publishing paper of mamatha (1)IOSR Journals
This document discusses classifying patterns under attacks and evaluating pattern security. It proposes a framework for assessing pattern security and modeling adversaries to characterize attack situations. The framework aims to provide a more comprehensive understanding of how classifiers behave under adversarial conditions. This can help lead to better design decisions that improve classifier security against considered attacks. Three applications are discussed - spam filtering, intrusion detection, and biometric verification - where pattern classifiers may be vulnerable if adversarial scenarios are not accounted for during design and evaluation.
New Approach for Determination of Propagation Model Adapted To an Environment...IOSR Journals
This document presents a new approach for determining a propagation model adapted to the environment of Yaounde, Cameroon using genetic algorithms. Radio measurements were taken in Yaounde's CDMA2000 1X-EVDO network across different environments. A genetic algorithm is used to develop a propagation model by minimizing the error between measured and predicted signal strengths. The new model is found to better represent the local environment compared to standard models like Okumura-Hata, based on a lower root mean squared error. The new model can be used for radio network planning in Yaounde.
New Approach for Determination of Propagation Model Adapted To an Environment...IOSR Journals
This document presents a new approach for determining a propagation model adapted to the environment of Yaounde, Cameroon using genetic algorithms. Radio measurements were taken in Yaounde's CDMA2000 1X-EVDO network across different environments. A genetic algorithm is used to develop a propagation model by minimizing the error between measured and predicted signal strengths. The new model is found to better represent the local environment compared to standard models like Okumura-Hata, based on a lower root mean squared error. The developed propagation model can be used for radio network planning in Yaounde.
This document presents a new approach for determining a propagation model adapted to the environment of Yaounde, Cameroon using genetic algorithms. Radio measurements were taken in Yaounde's CDMA2000 1X-EVDO network across different environments. A genetic algorithm is used to develop a propagation model by minimizing the error between measured and predicted signal strengths. The new model is found to better represent the local environment compared to standard models like Okumura-Hata, based on a lower root mean squared error. The developed propagation model can be used for radio network planning in Yaounde.
IRJET- Statistical Tuning of Hata Model for 3G Communication Networks at 1.85...IRJET Journal
This document summarizes a study that statistically tunes the Hata propagation model for 3G networks at 1.857GHz in Port Harcourt, Nigeria. Drive tests were conducted at three urban sites to collect field measurements of path loss. The measured data was compared to predictions from standard models including Hata, COST 231, and LEE. Hata was identified as the best fitting standard model. To improve accuracy, Hata's parameters were statistically optimized using linear regression on the measured data. The optimized Hata model reduced mean absolute percentage error from 15.0% to 13.35% compared to the standard Hata model, demonstrating its improved path loss prediction for the environment.
Final Performance Evaluation of 3GPP NR eMBB within 5G-PPP consortiumEiko Seidel
The document summarizes simulation results evaluating whether 3GPP NR (5G New Radio) technology meets the ITU-R 5G performance targets. Simulations were conducted for different scenarios like indoor hotspot, dense urban, and rural environments. Key findings include:
- In dense urban scenarios at 4GHz, the minimum requirements for user experience data rate and spectral efficiency were met. However, at 30GHz the requirements could not be fulfilled due to insufficient outdoor-to-indoor coverage.
- Minimum requirements were generally met across scenarios, except for some cases using high frequencies like 30GHz where outdoor-to-indoor links were infeasible.
- Area traffic capacity requirements for indoor hotspots were exceeded in
5.computer analysis of the cost 231 hata model for path loss estimation at 90...Alexander Decker
This document analyzes the suitability of the COST 231 Hata model for predicting radio signal propagation across mountainous terrain in Nigeria. Measurements of signal strength were taken from 5 base stations and compared to predictions from the COST 231 Hata model and a least squares approximation model. The COST 231 Hata model was found to have a root mean square error of 10.25dB, exceeding the acceptable threshold of 6dB, indicating it is not suitable for this terrain. A modified COST 231 Hata model was proposed by subtracting the root mean square error, and was found to have improved accuracy with a root mean square error of 5.1dB, indicating it is suitable for predicting signal propagation across this mountainous
IRJET- Performance Evaluation of DOA Estimation using MUSIC and Beamformi...IRJET Journal
This document presents a simulation study comparing the MUSIC algorithm and LMS adaptive beamforming algorithm for direction of arrival (DOA) estimation and beamforming in a smart antenna system. The MUSIC algorithm uses eigendecomposition to estimate the DOA of multiple signals and finds the position location of the desired user. The LMS algorithm then adapts the beam pattern by adjusting weights to maximize gain towards the desired user while nulling interference from other directions. The simulation results show sharp peaks in the MUSIC spectrum to accurately locate the desired user and deep nulls in the LMS beam pattern to suppress interference.
This document summarizes the results of a measurement campaign to characterize outdoor path loss models for IEEE 802.16 wireless networks in suburban and campus environments. Measurements were conducted at 3.5 GHz in two test areas near Rome, Italy - a suburban area around a BT Italy building and an Ericsson campus area. Path loss models including one-slope and free space were fitted to the measurement data from each area. The one-slope model provided better fits with R-squares of 0.37 and 0.71 for the suburban and campus areas, respectively. Link budget analysis using the one-slope models showed maximum coverage ranges of around 1 km for the suburban area and 1.5 km for the campus area.
IOSR Journal of Applied Physics (IOSR-JAP) is an open access international journal that provides rapid publication (within a month) of articles in all areas of physics and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in applied physics. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
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.
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.
Performance Analysis of Antenna Selection Techniques in MIMO-OFDM System with...IJECEIAES
In this paper we propose a new MIMO-OFDM model in which we consider various antenna selection techniques like Bulk selection and Per-subcarrier selection etc. with hardware impairments such as non-linearties of amplifiers, quantization noise, phase noise and I-Q imbalance etc. As we know that the transceiver hardware impairments limit the channel capacity and the energy efficiency of MIMO-OFDM system, so we can not neglect the fundamental impacts of these hardware impairments {Kappa (0.05 0.1)} on the energy efficiency in the high SNR domain. Therefore we analyze the Energy Efficiency of Bulk and Per-subcarrier antenna selection techniques with or without hardware impairments. It has been observed that the energy efficiency decreases as the value of these hardware impairments increases. As we compared the Bulk antenna selection with the Per-subcarrier antenna selection scheme, the Per-subcarrier antenna selection requires more number of RF (radio frequency) chains and transmits power in comparison to the Bulk selection. Due to this, the Bulk antenna selection technique is more energy efficient than Per-subcarrier antenna selection.
Application of smart antenna interference suppression techniques in tdscdmamarwaeng
This document discusses the application of smart antenna interference suppression techniques in TD-SCDMA systems. It first provides background on TD-SCDMA and smart antenna technology. It then describes two adaptive beamforming algorithms - LMS and RLS - and simulates their performance at interference suppression in MATLAB. The simulation results show that both algorithms can effectively form a main beam towards the desired user and nulls towards interferers. RLS converges faster than LMS, though it has higher computational complexity. The study demonstrates that smart antenna techniques can improve signal quality in TD-SCDMA systems by suppressing interference.
COMPARISON OF RADIO PROPAGATION MODELS FOR LONG TERM EVOLUTION (LTE) NETWORKijngnjournal
This paper concerns about the radio propagation models used for the upcoming 4th Generation (4G) of cellular networks known as Long Term Evolution (LTE). The radio wave propagation model or path loss model plays a very significant role in planning of any wireless communication systems. In this paper, a comparison is made between different proposed radio propagation models that would be used for LTE, like Stanford University Interim (SUI) model, Okumura model, Hata COST 231 model, COST Walfisch-Ikegami & Ericsson 9999 model. The comparison is made using different terrains e.g. urban, suburban and rural area.SUI model shows the lowest path lost in all the terrains while COST 231 Hata model illustrates highest path loss in urban area and COST Walfisch-Ikegami model has highest path loss for suburban and rural environments.
This document compares several radio propagation models that could be used for Long Term Evolution (LTE) networks: Stanford University Interim (SUI) model, Okumura model, COST 231 Hata model, COST Walfisch-Ikegami model, and Ericsson 9999 model. It analyzes the path loss predicted by each model in urban, suburban, and rural environments. The SUI model showed the lowest path loss in all terrains, while the COST 231 Hata model predicted the highest path loss in urban areas. The COST Walfisch-Ikegami model predicted the highest path loss for suburban and rural environments. Selecting the most accurate propagation model is important for planning L
Evaluation of BER in LTE System using Various Modulation Techniques over diff...ijtsrd
Wireless communication is one of the mainly active areas of tools progress and has become an ever more essential and prominent part of everyday life. Simulation of wireless channels accurately is very important for the intend and performance evaluation of wireless communication systems and components. We evaluated the act of available transmission modes in LTE. However, performance analysis can be done straightforward using evaluation of LTE. The performance of transmission modes are evaluated by calculating probability of Bit Error Rate BER versus Signal Noise Ratio SNR under the frequently used three wireless channel models AWGN, Rayleigh and Rician . We will consider the data modulation and data rate to analyze performance that is BER vs. SNR. A comparative analysis of QPSK and 16QAM, 32 QAM and 64 QAM will also provide knowledge base which helps for application development in real world. Parvesh Kumar | Shalini Bhadola | Kirti Bhatia ""Evaluation of BER in LTE System using Various Modulation Techniques over different Modulation Schemes"" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-3 | Issue-3 , April 2019, URL: https://www.ijtsrd.com/papers/ijtsrd23315.pdf
Paper URL: https://www.ijtsrd.com/engineering/computer-engineering/23315/evaluation-of-ber-in-lte-system-using-various-modulation-techniques-over-different-modulation-schemes/parvesh-kumar
Particle Swarm Optimization for the Path Loss Reduction in Suburban and Rural...IJECEIAES
In the present work, a precise optimization method is proposed for tuning the parameters of the COST231 model to improve its accuracy in the path loss propagation prediction. The Particle Swarm Optimization is used to tune the model parameters. The predictions of the tuned model are compared with the most popular models. The performance criteria selected for the comparison of various empirical path loss models is the Root Mean Square Error (RMSE). The RMSE between the actual and predicted data are calculated for various path loss models. It turned out that the tuned COST 231 model outperforms the other studied models.
3D METALLIC PLATE LENS ANTENNA BASED BEAMSPACE CHANNEL ESTIMATION TECHNIQUE F...ijwmn
Beamspace channel estimation mechanism for massive MIMO (multiple input multiple output) antenna
system presents a major process to compensate the 5G spectrum challenges caused by the proliferation of
information from mobile devices. However, this estimation is required to ensure the perfect channel state
information (CSI) for lower amount of Radio Frequency (RF) chains for each beam. In addition, phase
shifter (PS) components used in this estimation need high power to select the beam in the desired direction.
To overcome these limitations, in this work, we propose Regular Scanning Support Detection (RSSD)
based channel estimation mechanism. Moreover, we utilise a 3D lens antenna array having metallic plate
and a switch in our model which compensates the limitation of phase shifters. Simulation results show that
the proposed RSSD based channel estimation surpasses traditional technique and SD based channel
estimation even in lower SNR area which is highly desirable in the millimeter wave (mmWave) massive
MIMO systems.
- The document analyzes the effect of varying antenna gain and sectorization on site requirements for an LTE radio access network.
- It models three site layouts: single omni-directional antenna sites, 3-sector sites with directional antennas per sector, and 6-sector sites.
- Link budget calculations are performed for different clutter types to estimate the number of sites needed to cover the deployment area under each configuration.
A robust doa–based smart antenna processor for gsm base stationsmarwaeng
This document summarizes a robust smart antenna processor for GSM base stations that uses direction-of-arrival (DOA) estimation. It estimates DOAs in the uplink using multiple algorithms, including unitary ESPRIT and Capon's beamformer. It then tracks DOAs separately for uplink and downlink to form antenna patterns that suppress interference. By adapting weights within each GSM frame, it provides up to a 35dB improvement in signal-to-noise-and-interference ratio and outperforms conventional beamformers that place sharp nulls.
This document provides a technical review of secure banking using RSA and AES encryption methodologies. It discusses how RSA and AES are commonly used encryption standards for secure data transmission between ATMs and bank servers. The document first provides background on ATM security measures and risks of attacks. It then reviews related work analyzing encryption techniques. The document proposes using a one-time password in addition to a PIN for ATM authentication. It concludes that implementing encryption standards like RSA and AES can make transactions more secure and build trust in online banking.
This document analyzes the performance of various modulation schemes for achieving energy efficient communication over fading channels in wireless sensor networks. It finds that for long transmission distances, low-order modulations like BPSK are optimal due to their lower SNR requirements. However, as transmission distance decreases, higher-order modulations like 16-QAM and 64-QAM become more optimal since they can transmit more bits per symbol, outweighing their higher SNR needs. Simulations show lifetime extensions up to 550% are possible in short-range networks by using higher-order modulations instead of just BPSK. The optimal modulation depends on transmission distance and balancing the energy used by electronic components versus power amplifiers.
This document provides a review of mobility management techniques in vehicular ad hoc networks (VANETs). It discusses three modes of communication in VANETs: vehicle-to-infrastructure (V2I), vehicle-to-vehicle (V2V), and hybrid vehicle (HV) communication. For each communication mode, different mobility management schemes are required due to their unique characteristics. The document also discusses mobility management challenges in VANETs and outlines some open research issues in improving mobility management for seamless communication in these dynamic networks.
This document provides a review of different techniques for segmenting brain MRI images to detect tumors. It compares the K-means and Fuzzy C-means clustering algorithms. K-means is an exclusive clustering algorithm that groups data points into distinct clusters, while Fuzzy C-means is an overlapping clustering algorithm that allows data points to belong to multiple clusters. The document finds that Fuzzy C-means requires more time for brain tumor detection compared to other methods like hierarchical clustering or K-means. It also reviews related work applying these clustering algorithms to segment brain MRI images.
1) The document simulates and compares the performance of AODV and DSDV routing protocols in a mobile ad hoc network under three conditions: when users are fixed, when users move towards the base station, and when users move away from the base station.
2) The results show that both protocols have higher packet delivery and lower packet loss when users are either fixed or moving towards the base station, since signal strength is better in those scenarios. Performance degrades when users move away from the base station due to weaker signals.
3) AODV generally has better performance than DSDV, with higher throughput and packet delivery rates observed across the different user mobility conditions.
This document describes the design and implementation of 4-bit QPSK and 256-bit QAM modulation techniques using MATLAB. It compares the two techniques based on SNR, BER, and efficiency. The key steps of implementing each technique in MATLAB are outlined, including generating random bits, modulation, adding noise, and measuring BER. Simulation results show scatter plots and eye diagrams of the modulated signals. A table compares the results, showing that 256-bit QAM provides better performance than 4-bit QPSK. The document concludes that QAM modulation is more effective for digital transmission systems.
The document proposes a hybrid technique using Anisotropic Scale Invariant Feature Transform (A-SIFT) and Robust Ensemble Support Vector Machine (RESVM) to accurately identify faces in images. A-SIFT improves upon traditional SIFT by applying anisotropic scaling to extract richer directional keypoints. Keypoints are processed with RESVM and hypothesis testing to increase accuracy above 95% by repeatedly reprocessing images until the threshold is met. The technique was tested on similar and different facial images and achieved better results than SIFT in retrieval time and reduced keypoints.
This document studies the effects of dielectric superstrate thickness on microstrip patch antenna parameters. Three types of probes-fed patch antennas (rectangular, circular, and square) were designed to operate at 2.4 GHz using Arlondiclad 880 substrate. The antennas were tested with and without an Arlondiclad 880 superstrate of varying thicknesses. It was found that adding a superstrate slightly degraded performance by lowering the resonant frequency and increasing return loss and VSWR, while decreasing bandwidth and gain. Specifically, increasing the superstrate thickness or dielectric constant resulted in greater changes to the antenna parameters.
This document describes a wireless environment monitoring system that utilizes soil energy as a sustainable power source for wireless sensors. The system uses a microbial fuel cell to generate electricity from the microbial activity in soil. Two microbial fuel cells were created using different soil types and various additives to produce different current and voltage outputs. An electronic circuit was designed on a printed circuit board with components like a microcontroller and ZigBee transceiver. Sensors for temperature and humidity were connected to the circuit to monitor the environment wirelessly. The system provides a low-cost way to power remote sensors without needing battery replacement and avoids the high costs of wiring a power source.
1) The document proposes a model for a frequency tunable inverted-F antenna that uses ferrite material.
2) The resonant frequency of the antenna can be significantly shifted from 2.41GHz to 3.15GHz, a 31% shift, by increasing the static magnetic field placed on the ferrite material.
3) Altering the permeability of the ferrite allows tuning of the antenna's resonant frequency without changing the physical dimensions, providing flexibility to operate over a wide frequency range.
This document summarizes a research paper that presents a speech enhancement method using stationary wavelet transform. The method first classifies speech into voiced, unvoiced, and silence regions based on short-time energy. It then applies different thresholding techniques to the wavelet coefficients of each region - modified hard thresholding for voiced speech, semi-soft thresholding for unvoiced speech, and setting coefficients to zero for silence. Experimental results using speech from the TIMIT database corrupted with white Gaussian noise at various SNR levels show improved performance over other popular denoising methods.
This document reviews the design of an energy-optimized wireless sensor node that encrypts data for transmission. It discusses how sensing schemes that group nodes into clusters and transmit aggregated data can reduce energy consumption compared to individual node transmissions. The proposed node design calculates the minimum transmission power needed based on received signal strength and uses a periodic sleep/wake cycle to optimize energy when not sensing or transmitting. It aims to encrypt data at both the node and network level to further optimize energy usage for wireless communication.
This document discusses group consumption modes. It analyzes factors that impact group consumption, including external environmental factors like technological developments enabling new forms of online and offline interactions, as well as internal motivational factors at both the group and individual level. The document then proposes that group consumption modes can be divided into four types based on two dimensions: vertical (group relationship intensity) and horizontal (consumption action period). These four types are instrument-oriented, information-oriented, enjoyment-oriented, and relationship-oriented consumption modes. Finally, the document notes that consumption modes are dynamic and can evolve over time.
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C010211624
1. IOSR Journal of Electrical and Electronics Engineering (IOSR-JEEE)
e-ISSN: 2278-1676,p-ISSN: 2320-3331, Volume 10, Issue 2 Ver. I (Mar – Apr. 2015), PP 16-24
www.iosrjournals.org
DOI: 10.9790/1676-10211624 www.iosrjournals.org 16 | Page
Optimization of Okumura Hata Model in 800MHz based on
Newton Second Order algorithm. Case of Yaoundé, Cameroon
Deussom Djomadji Eric Michel1
, Tonye Emmanuel2
.
1&2
(Department of Electrical and Telecommunications Engineering; National Advanced School of Engineering
of Yaoundé ; University of Yaoundé I, CAMEROON)
Abstract: Propagation models are essential tools for planning and optimization in mobile radio networks. In
this paper we optimize Okumura Hata model by using an iterative algorithm based on Newton second order
method. For that, radio measurements were made on the existing CDMA2000 1X-EVDO network through drive
test on 800MHz frequency band. Calculating the root mean squared error (RMSE) between the actual
measurement data and radio data from the prediction model developed allows validation of the results. A
comparative study is made between the value of the RMSE obtained by the new model and those obtained by the
standard model of OKUMURA HATA. We can conclude that the new model is better and more representative of
our local environment than that of OKUMURA HATA. The new model obtained can be used for future radio
planning when the government will open the market for LTE deployment in 800MHz in the city of Yaoundé,
Cameroon.
Keywords: Drive test, Newton second order algorithm, propagation models, root mean square error.
I. Introduction
A propagation model suitable for a given environment is an essential element in the planning and
optimization of a mobile network. A proper planning of the coverage will enable the users to enjoy all services
everywhere in the coverage area. In 4G network, the subscribers should access internet service with high data
rate. The handoff performance should be also high to satisfy subscribers requirements in terms of mobility and
service availability. To enable users to access different mobile services, particular emphasis must be made on
the size of the radio coverage. Propagation models are widely used in the network planning, in particular for the
completion of feasibility studies and initial deployment of the network, for new network deployment like LTE,
or when some new extensions are needed especially in the new metropolises. To determine the characteristics of
radio propagation channel, tests of the real propagation models and calibration of the existing models are
required to obtain a propagation model that accurately reflects the characteristics of radio propagation in a given
environment. There are several softwares used for planning that include calibration of models on the market
namely: ASSET of the firm AIRCOM in England, PLANET of the MARCONI Company, and ATTOL of the
French company FORK etc.
Several authors were also interested in the calibration of the propagation models, we have for example:
Chhaya Dalela, and all [1] who worked on 'tuning of Cost231 Hata model for radio wave propagation
prediction'; Deussom E. and Tonye E. [2] who work on “New Approach for Determination of Propagation
Model Adapted To an Environment Based On Genetic Algorithms: Application to the City Of Yaoundé,
Cameroon”; Medeisis and Kajackas [3] presented "the tuned Okumura Hata model in urban and rural areas at
Lituania at 160, 450, 900 and 1800 MHz bands; Prasad et al. [4] worked on "tuning of COST-231.
"Hata model based on various data sets generated over various regions of India ', Mardeni & Priya [5]
presented optimized COST - 231 Hata model to predict path loss for suburban and open urban environments in
the 2360-2390 MHz.
In our study, we use the data collected through drive test in existing CDMA1X EVDO RevB network
in the city of Yaoundé. The frequency band of the network is 800MHz.Once getting the optimized model; it
could be used for the planning of the future LTE in 800MHz band. To achieve this goal, we use 4 BTS
distributed all around the city.
We propose an approach of model optimization based on Newton second order method.
In this document, sometimes will use the abbreviation NSO for Newton Second Order.
This article will be articulated as follows: in section 2, the experimental details will be presented,
followed by a description of the methodology adopted in section 3. The results of the implementation of the
algorithm, the validation of the results and comments will be provided in section 4 and finally a conclusion will
be presented in section 5.
2. Optimization of Okumura Hata Model in 800MHz based on Newton Second Order algorithm…
DOI: 10.9790/1676-10211624 www.iosrjournals.org 17 | Page
II. Experimental Details
2.1 Propagation environment.
This study is done in the city of Yaoundé, capital of Cameroon. We relied on the existing CDMA 2000
1X-EVDO network for doing drive test in the city. To do this, we divided the city into 2 categories namely:
downtown Yaoundé, the downtown to periphery area and finally the outskirts of the city. For each category, we
used 2 types of similar environments, and then compared the results obtained between them. We have the table
below which shows the categories with the concerned BTS:
Table 1: Types of environment
Categories A B
Urban characteristics Dense urban Urban
Concerned BTS Ministere PTT (A1) Bastos (A2)
Hotel du plateau(B1)
Biyem Assi(B2)
2.2 Equipments description
2.2.1 Simplified description of BTS used.[6]
BTS that we used for our drive tests are the ones provided by the equipment manufacturer HUAWEI
Technologies. We used 2 types of BTS: BTS3606 and DBS3900 all CDMA. The following table shows the
specifications of the BTS according to the type.
Table 2: BTS characteristics
BTS3606 DBS3900
BTS types Indoor BTS Distributed BTS (Outdoor)
Number of sectors 3 3
Frequency Band Band Class 0 (800 MHz) Band Class 0 (800 MHz)
Downlink frequency 869 MHz - 894 MHz 869 MHz - 894 MHz
Uplink frequency 824 MHz - 849 MHz 824 MHz - 849 MHz
Max power (mono carrier) 20 W 20 W
BTS Total power (dBm) 43 dBm 43 dBm
The BTS engineering parameters are presented in the table below:
Table 3: BTS engineering parameters
1.3 Others equipments parameters.
In order to perform the drive tests, we used a Toyota Prado VX vehicle, an ACER ASPIRE laptop,
drive test software namely Pilot pioneer of Dingli communication V6.0, a LG CDMA mobile terminal, a GPS
terminal, a DC/AC converter to power the PC during the measurement.
The drive test done in the area A1, A2, B1, B2 gave the following results.
Figure 1: Drive test in centre town (A1 left side image) and in Bastos area (A2 right side image).
BTS informations
BTS
Type
BTS name
Latitude
(degree)
Longitude
(degree)
BTS
Altitude
(m)
Antenna
height
Mean
elevation
Antenna
effective
height
Antenna’s
Gain(dB
i)
7/8
Feeder
Cable(m)
3606 MinistryPTT_800 3.86587 11.5125 749 40 741.82 47.18 15.5 45
3900 Hotel du plateau 3.87946 11.5503 773 27 753.96 46.04 17 0
3606 Biyem-Assi_800 3.83441 11.4854 721 40 709.54 51.46 15.5 45
3900 Camtel Bastos 3.89719 11.50854 770 28 754.86 43.14 17 0
3. Optimization of Okumura Hata Model in 800MHz based on Newton Second Order algorithm…
DOI: 10.9790/1676-10211624 www.iosrjournals.org 18 | Page
Figure 2: Drive test in Essos (B1 left side image) and Biyem Assi (B2 right side image)
III. Methodology
Many propagation models exist in the scientific literature, we present only the Okumura Hata model on
which we relied for this work.
3.1 Okumura-Hata propagation model [7]
The General form of Okumura Hata model is given by the following equation for urban area:
𝐿 = 69.55 + 26.16log 𝑓𝑐 − 13.82 log 𝑏 + 44.9 − 13.82 log 𝑏 ∗ 𝑙𝑜𝑔(𝑑) − 𝐸 (1)
With 𝐸 = 3.2 log 11.75 𝑚
2
− 4.97 , for hm=1.5 ; E = −9.1905 ∗ 10−4
≈ 0, which can be neglected.
Considering the following standard form given by equation (2):
Lp = 𝐾1 + 𝐾2 ∗ log 𝑑 + 𝐾3 ∗ (𝐻 𝑚 ) + 𝐾4 ∗ log 𝐻 𝑚 + 𝐾5 ∗ log 𝐻𝑏 + 𝐾6 ∗ log 𝐻𝑏 ∗ log(𝑑) (2)
It is possible to determine the corresponding Okumura Hata model coefficients, these coefficients are contained
in the table below:
Table 4: Okumura Hata model writen on the form of equation (2)
K1 K2 K3 K4 K5 K6
Okumura Hata 146,56 44,9 0 0 -13,82 -6,55
Equation (2) can also be written as:
Lp = 𝐾1 + 𝐾3 ∗ 𝐻 𝑚 + 𝐾4 ∗ log 𝐻 𝑚 + 𝐾5 ∗ log 𝐻𝑏 + [𝐾2 + 𝐾6 ∗ log 𝐻𝑏 ] ∗ log 𝑑 (3)
Assuming 𝐴 = 𝐾1 + 𝐾3 ∗ (𝐻 𝑚) + 𝐾4 ∗ log 𝐻 𝑚 + 𝐾5 ∗ log 𝐻 𝑏 and 𝐵 = 𝐾2 + 𝐾6 ∗ log 𝐻 𝑏
The equation below is obtained in matrix form: 𝐿 𝑝 = 1 log(𝑑) ∗
𝐴
𝐵
(4)
It is this last modified form that we will eventually use for our work.
3.2 Determination flowchart
The flowchart below represents the determination of the propagation model using NSO algorithm.
4. Optimization of Okumura Hata Model in 800MHz based on Newton Second Order algorithm…
DOI: 10.9790/1676-10211624 www.iosrjournals.org 19 | Page
Figure 5: Algorithm implementation flowchart
In this chart, data filtering is made according to the criteria for distance and signal strength received:
Table 5: filtering criteria. [7], [8]
3.3 Presentation of Newton second order method. [9]
In calculus, Newton's method is an iterative method for finding the roots of a differentiable function f.
Newton second order iterative scheme for a function of several dimensions can be express as:
𝐾𝑛 = 𝐾𝑛−1 + [𝐻 𝑓 −1
] ∗ ∆ 𝑓 , (5)
Where ∆ 𝑓 represents the gradient of the function f and H(f) the hessian matrix of f.
Here it comes to seek a solution of the equation f (K) = 0 by performing successive iterations on the vector K.
We will model our problem in the form of the second order Newton algorithm.
First of all, we will classify the parameters of the equation (2) into two major groups [10]:
-The global adjustment parameters.
- Micro adjustment parameters.
The global adjustment parameters here are K1 and K2, while the other coefficients are parameters of
micro adjustment and as such, their default values in the standard model can be considered constants.
Using equation (5) above for N radio measurement points, for different distances di we will obtain the
corresponding propagation loss values Li , then equation (5) will become:
𝐿𝑖 = 𝐴 + 𝐵 ∗ 𝑙𝑜𝑔(𝑑𝑖) This could be also written as:
𝐿𝑖 = 1 log(𝑑𝑖) ∗
𝐴
𝐵
, (6)
And for all the measurements points we will deducted the following:
𝐿1
𝐿2
⋮
𝐿 𝑁
=
1 log(𝑑1)
1 log(𝑑2)
⋮
1 log(𝑑 𝑁)
∗
𝐴
𝐵
(7)
Minimum distance (m) 100
Maximum distance (m) 10 000
Minimum received power (dBm) -110
Maximum received power (dBm) -40
5. Optimization of Okumura Hata Model in 800MHz based on Newton Second Order algorithm…
DOI: 10.9790/1676-10211624 www.iosrjournals.org 20 | Page
And assuming: 𝑀 =
1 log(𝑑1)
1 log(𝑑2)
⋮
1 log(𝑑 𝑁)
and 𝐾 =
𝐴
𝐵
; we will obtain: 𝐿 = 𝑀 ∗ 𝐾 (8)
Our target is to minimize the Euclidean distance between the prediction values contained in the vector L and the
measured values of the propagation loss LM [13].
Let 𝐸 =
1
𝑁
𝐿 𝑀 − 𝑀 ∗ 𝐾 2
(9), the mean square error. We are looking for a vector K which minimize E. So E
here is our objective function, we can also remark that E is a quadratic function related to the variable K. In
other to implement Newton second algorithm according to equation (5), we should find the gradient and Hessian
of E. Equation (9) can also be written as 𝐸 =
1
𝑁
∗ ( 𝑀 ∗ 𝐾 2
− 2 𝑀 ∗ 𝐾 . 𝐿 𝑀 + 𝐿 𝑀
2
) where <.> represents
the scalar product. Then 𝑁 ∗ 𝐸 = 𝑀 ∗ 𝐾 2
− 2 𝑀 ∗ 𝐾 . 𝐿 𝑀 + 𝐿 𝑀
2
;
𝑁 ∗ 𝐸 = 𝐾 𝑇
𝑀 𝑇
𝑀𝐾 − 2𝐾 𝑇
𝑀 𝑇
𝐿 𝑀 + 𝐿 𝑀
𝑇
𝐿 𝑀 Where KT
represents the transpose of vector K.
We can then deduct the gradient as following:
𝜕(𝑁𝐸)
𝜕𝐾
=
𝜕(𝐾 𝑇 𝑀 𝑇 𝑀𝐾−2𝐾 𝑇 𝑀 𝑇 𝐿 𝑀 +𝐿 𝑀
𝑇
𝐿 𝑀 )
𝜕𝐾
This gives
𝜕(𝑁𝐸)
𝜕𝐾
= 2𝑀 𝑇
𝑀𝐾 − 2𝑀 𝑇
𝐿 𝑀
And
𝜕(𝐸)
𝜕𝐾
= ∆ 𝐸 =
1
𝑁
∗ (2𝑀 𝑇
𝑀𝐾 − 2𝑀 𝑇
𝐿 𝑀) (10)
The hessian matrix of (N*E) can also be deducted by
𝜕2(𝑁∗𝐸)
𝜕𝐾2 =
𝜕(2𝑀 𝑇 𝑀𝐾−2𝑀 𝑇 𝐿 𝑀)
𝜕𝐾
= 2𝑀 𝑇
𝑀
Finally, the Hessian of E will then be: 𝐻(𝐸) =
2
𝑁
𝑀 𝑇
𝑀 (11)
The final iterative scheme is then: 𝐾𝑛 = 𝐾𝑛−1 + [𝐻 𝑓 −1
] ∗ ∆ 𝑓 this gives
𝐾𝑛 = 𝐾𝑛−1 +
1
𝑁
∗ [
2
𝑁
𝑀 𝑇
𝑀]−1
(2𝑀 𝑇
𝑀𝐾 − 2𝑀 𝑇
𝐿 𝑀) , This can be rearranged as:
𝑲 𝒏 = 𝑲 𝒏−𝟏 + 𝒊𝒏𝒗(𝑴 𝑻
𝑴) ∗ (𝑴 𝑻
𝑴𝑲 − 𝑴 𝑻
𝑳 𝑴) ; n≥1, where inv(X) refer to the inverse of the matrix X. (12)
The equation (12) is the key point of this study, the following algorithm presents is based on it.
According to [10] we know that a propagation model is précised and feat a local environment if it’s Root Mean
Square Error (RMSE) is less than 8dB. In fact 𝑅𝑀𝑆𝐸 = 𝐸, then we can define a stopping criteria of our
iterations which is: 𝑬 ≤ 𝟔𝟒. But for complex environments and in some special cases, it could be found that E is
always greater than 64, so another stopping criteria based on the maximum number of iterations should be also
added, otherwise we could be dropped inside an infinite loop.
We will therefore have the implementation algorithm below:
Begin
D ; % The vector that contains the distances between BTS and MS gotten through drive test
K= [0 ; 0] ; % initialization of K .
Eseuil=64 ; % We fix the mean square threshold to 64
It=20 ; % We fix the maximum iterations number to 20
%Generation of matrix M
For i=1 : N
M (i, 1)=1 ; M (i, 2)=log (D(i)) ;
End
Iteration=0 ;
e = L-M*K; % e ERROR function
Fit_new=1/N*(eT
*e); % Fit: mean square error
O=MT
*M; % Temporal vector to make the iteration easy
While (Fit_new >Eseuil)
iteration=iteration+1;
if iteration < 20
G=2*1/N*(-MT
*L + O*K); %Gradient calculation
H=2*1/N*O; % H=2/N*O; Hessian calculation
K=K-inv(H)*G; % Newton iteration
e =L-M*K; % updating e for next iteration
6. Optimization of Okumura Hata Model in 800MHz based on Newton Second Order algorithm…
DOI: 10.9790/1676-10211624 www.iosrjournals.org 21 | Page
Fit_new=1/N*(eT
*e));
else
Break % We break the while loop
End
End
End
After running the algorithm, we will have the solution which is a vector 𝐊∗
=
𝐀
𝐁
for our optimization problem.
Through this we can deduct that for K3, K4, K5 and K6 constants, we can have:
𝐊 𝟏 = 𝐀 − (𝐊 𝟑 ∗ (𝐇 𝐦) + 𝐊 𝟒 ∗ 𝐥𝐨𝐠 𝐇 𝐦 + 𝐊 𝟓 ∗ 𝐥𝐨𝐠 𝐇 𝐛 ) (13)
𝐊 𝟐 = 𝐁 − 𝐊 𝟔 ∗ 𝐥𝐨𝐠 𝐇 𝐛 (14)
Now we have clearly defined our determination procedure. The next step is to present what we got as result after
implementing our algorithm on data sets collected.
IV. Results and comments
Having implemented the method presented above on radio measurements data obtained in the city of
Yaoundé, we have obtained the results as presented below.
4.1 Results per area
We obtained the representatives curves below, the actual measurements are in blue, Okumura Hata
model in black, the optimized model obtained via Newton second order method in red.
For the implementation we have considered the following value: K3=-2.49, K4=0; K5=-13.82; K6=-6.55;
a) AreaA1 : Yaoundé centre town.
The following table presents the result obtain in area A1 using Newton second order algorithm:
Table 6: result in centre town.
Area Results K1 K2 K3 K4 K5 K6 RMSE
A1
Newton 2nd
order 134.89 37.29 -2.49 0 -13.82 -6.55 6.7137
Okumura Hata 146.56 44.9 0 0 -13.82 -6.55 14.9345
We can remark that the RMSE obtained by the algorithm is less than 8dB and better than that of Okumura Hata.
The following figure presents the actual data gotten from field, the curves of Okumura Hata and the optimized
model.
Figure 6: Actual data in Centre town VS predicted measurements.
b) Area A2 : Bastos area (Ambassy quaters)
0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2
70
80
90
100
110
120
130
140
Distance en Km
LendB
Pertes de propagation L=f(d)
Lreel
LNew ton
LOk
7. Optimization of Okumura Hata Model in 800MHz based on Newton Second Order algorithm…
DOI: 10.9790/1676-10211624 www.iosrjournals.org 22 | Page
Figure 7: Actual data in Bastos VS predicted measurements.
The table below gives the results of newton second order algorithm.
Table 7: Results from bastos area.
Area Results K1 K2 K3 K4 K5 K6 RMSE
A2 Newton 2nd order 138.93 27.71 -2.49 0 -13.82 -6.55 6.1059
Okumura Hata 146.56 44.9 0 0 -13.82 -6.55 11.2924
Note that we have a RMSE <8dB which confirms the reliability of the result.
c) Area B1 : Biyem Assi area
We have the figure below.
Figure 8: Actual data in Biyem Assi VS predicted measurements.
The table below gives the results of NSO algorithm.
Table 8: Results from Biyem Assi area.
Zone Résultats K1 K2 K3 K4 K5 K6 RMSE
B1
Newton 2nd
order 131.90 23.17 -2.49 0 -13.82 -6.55 5.3883
Okumura Hata 146.56 44.9 0 0 -13.82 -6.55 12.3604
0 0.5 1 1.5 2 2.5
80
90
100
110
120
130
140
Distance en Km
LendB
Pertes de propagation L=f(d)
Lreel
LNew ton
LOk
0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 1.1
75
80
85
90
95
100
105
110
115
120
125
Distance en Km
LendB
Pertes de propagation L=f(d)
Lreel
LNew ton
LOk
8. Optimization of Okumura Hata Model in 800MHz based on Newton Second Order algorithm…
DOI: 10.9790/1676-10211624 www.iosrjournals.org 23 | Page
Note that we have a RMSE <8dB which confirms the reliability of the result and which is better than the one of
Okumura Hata.
d) Area B2 : Essos-Mvog Ada area
Figure 9: Actual data in Essos Camp Sonel area VS predicted measurements.
The table below gives the results of NSO algorithm.
Table 9: Results from Essos Mvog Ada area.
Zone Résultats K1 K2 K3 K4 K5 K6 RMSE
B2
Newton 2nd
order 141.75 36.53 -2.49 0 -13.82 -6.55 7.3907
Okumura Hata 146.56 44.9 0 0 -13.82 -6.55 11.5989
Note that we have a RMSE <8dB which confirms the reliability of the result
4.2 Summary of results
In all the area A1, A2, B1, B2 above, the RMSE obtain through the new model made up using NSO is
better than the one calculate using Okumura Hata model. After testing, we find that the solution is gotten with
only one iteration. This can be explained by the fact that our objective function is a quadratic one. For the whole
town of Yaoundé, given that we always got a RMSE < 8dB, we can deduce the final solution as the average of
the solution gotten in each area. The final result and the corresponding formula are given below.
Table 12: Optimized propagation model retained
Method K1 K2 K3 K4 K5 K6
Final solution NSO 136.86 31.17 -2.49 0 -13.82 -6.55
Before retaining the result of table 12 as our optimized propagation model, let check that it is accurate for all
area A1, A2, B1 and B2. The table below presents the RMSE obtained using the new model in all the considered
area.
Table 13: RMSE evaluation for the optimized model per area.
Area A1 A2 B1 B2
RMSE(Optimized model) 7.8791 6.8575 6.0403 8.9573
RMSE(Okumura Hata) 14.9345 11.2924 12.3604 11.5989
We clearly see that the optimized RMSE is always better than the one of Okumura Hata.
The final model equation is
𝐋 = 𝟏𝟑𝟔. 𝟖𝟔 + 𝟑𝟏. 𝟏𝟕 𝐥𝐨𝐠 𝐝 − 𝟐. 𝟒𝟗 ∗ 𝐡 𝐦 − 𝟏𝟑. 𝟖𝟐 ∗ 𝐥𝐨𝐠 𝐇 𝐞𝐟𝐟 − 𝟔. 𝟓𝟓 ∗ 𝐥𝐨𝐠 𝐇 𝐞𝐟𝐟 ∗ 𝐥𝐨𝐠(𝐝) (15)
This final formula can be seen as the propagation model adapted to the environment of Yaoundé.
0 0.5 1 1.5 2 2.5
80
90
100
110
120
130
140
Distance en Km
LendB
Pertes de propagation L=f(d)
Lreel
LNew ton
LOk
9. Optimization of Okumura Hata Model in 800MHz based on Newton Second Order algorithm…
DOI: 10.9790/1676-10211624 www.iosrjournals.org 24 | Page
V. Conclusion
This paper presents the use of a Newton second order algorithm (see equation 12) to optimize existing
Okumura Hata model in the frequency band of 800MHz relatively to a given environment. The method
described here gave us a very good result and could very well be used to design or calibrate propagation models.
This method is relatively simple to implement and the result can be quickly be obtained. 2 stopping criteria were
defined for the implementation of the algorithm, one based on the maximum number of iterations and another
based on the RMSE threshold that we which to satisfied. Measurements made on the city of Yaoundé as
application gave us very good results with an RMSE less than 8dB for all the selected areas in the city. Compare
to Okumura Hata RMSE obtained, the new model gives a better result .This means that it is accurate. Despite
the fact that we presented the algorithm using Okumura Hata model in a specific band, it doesn’t restrict its
utilization. This method can then be applied to optimize propagation model for deployment of LTE network in
any frequency anywhere.
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