This paper proposed a design of optical switching controller using FPGA for OCDMA encoder system. The encoder is one
of the new technologies that use to transmit the coded data in the optical communication system by using FPGA and optical switches.
It is providing a high security for data transmission due to all data will be transmitting in binary code form. The output signals from
FPGA are coded with a binary code that given to an optical switch before it signal modulate with the carrier and transmit to the
receiver. In this paper, AA and 55 data were used for source 1 and source 2. It is generated sample data and sent packet data to the
FPGA and stored it into RAM. The simulation results have done by using software Verilog Spartan 2 programming to simulate. After
that the output will produces at waveform to display the output. The main function of FPGA controlling unit is producing single pulse
and configuring optical switching system.
Performance Improvement of IEEE 802.22 WRAN Physical LayerIOSR Journals
The spectrum available for the wireless services is limited, the increased demand of wireless
application has put a lot of limitations on the utilization of available radio spectrum. For the efficient spectrum
utilization for wireless application IEEE 802.22 standard i.e. WRAN (Wireless Regional Area Network) is
developed which is based on cognitive radio technique that senses the free available spectrum. It allows sharing
of geographically unused channels allocated to the TV Broadcast Service, without interference.
In this paper we are evaluating the performance of WRAN over physical layer with QPSK, 16-QAM
and 64-QAM modulation with Convolution coding with code rate of 1/2, 2/3, 3/4, 5/6 and obtaining the BER
curves for rician channel. Simulation is performed in MATLAB
This document discusses the implementation of an interleaver on an FPGA for wireless communication systems. It proposes a novel finite state machine (FSM) based approach to model a multimode address generator for a WiMAX interleaver using VHDL on an FPGA. The proposed interleaver works better at high frequencies compared to existing FPGA approaches and uses minimal logic cells. It also studies interleaving techniques in OFDM-based wireless local area networks and discusses designing the interleaver using the internal memory blocks of an FPGA.
This document summarizes a research paper that proposes using parallel concatenated turbo codes in wireless sensor networks in an adaptive way. The key points are:
1) Turbo codes can achieve near-Shannon limit performance but decoding is complex, making them difficult to implement on energy-constrained sensor nodes.
2) The proposed approach shifts the complex turbo decoding to the base station while sensor nodes implement encoding and basic error correction.
3) At sensor nodes, a parallel concatenated convolutional code (PCCC) circuit encodes data and detects/corrects errors in forwarded packets. This improves energy efficiency and reliability over the wireless sensor network.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Comparative study of various voip applications in 802.11 a wireless network s...ijmnct
Today, Voice over Wireless Local Area Network (VOWLAN) is the most accepted Internet application.
There are a large number of literatures regarding the performance of various WLAN networks. Most of
them focus on simulations and modeling, but there are also some experiments with real networks. This
paper explains the comparison of performance of two different VOIP (Voice over Internet Protocol)
applications over the same IEEE 802.11a wireless network. Radio link standard 802.11a have maximum
transmission rate of 54Mbps. First protocol is session initiation protocol (SIP) and second is H.323
protocol. First one has an agent called SIP proxy. Second have a gateway reflects the characteristics of a
Switched Circuit Network (SCN). With this comparison we have required to obtain a better understanding
of wireless network suitability for voice communication in IP network.
Error Control and performance Analysis of MIMO-OFDM Over Fading ChannelsIOSR Journals
ABSTRACT: Multiple Input Multiple Output is a wireless technology that uses multiple transmitters and
receivers to transfer more data at the same time. Orthogonal Frequency Division Multiplexing, an FDM
modulation technique which splits the signal into multiple smaller sub-signals that are then transmitted
simultaneously at different frequencies to the receiver. OFDM technique spreads the data over number of
carriers which are at specific predefined frequencies. This reduces or eliminates the ISI. Forward error
correction or channel coding is a technique used for controlling errors in data transmission over unreliable or
noisy communication channels. The objective of our proposed paper is to implement the FEC into the MIMO
OFDM systems and its performance is analysed by using MATLAB over different fading channels. For
modulation it employs M-QAM which combines both ASK and PSK thereby enabling several bits to be
transmitted per symbol. The performance of MIMO-OFDM system is evaluated by BER Vs SNR when the bits
propagates through the different fading channels.
Keywords– OFDM, MIMO, QAM, FEC, BER.
Comparative study of_digital_modulation (1)Bindia Kumari
This document compares different digital modulation techniques that can be used in orthogonal frequency division multiplexing (OFDM) and WiMAX networks. It simulates BPSK, QPSK, 16-QAM and 64-QAM modulation in MATLAB and measures their performance in terms of bit error rate and throughput. The results show that higher order modulations like 64-QAM provide much higher throughput but also higher bit error rates compared to lower order modulations at a given signal-to-noise ratio. The best configuration balances low bit error rates and high throughput.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
Performance Improvement of IEEE 802.22 WRAN Physical LayerIOSR Journals
The spectrum available for the wireless services is limited, the increased demand of wireless
application has put a lot of limitations on the utilization of available radio spectrum. For the efficient spectrum
utilization for wireless application IEEE 802.22 standard i.e. WRAN (Wireless Regional Area Network) is
developed which is based on cognitive radio technique that senses the free available spectrum. It allows sharing
of geographically unused channels allocated to the TV Broadcast Service, without interference.
In this paper we are evaluating the performance of WRAN over physical layer with QPSK, 16-QAM
and 64-QAM modulation with Convolution coding with code rate of 1/2, 2/3, 3/4, 5/6 and obtaining the BER
curves for rician channel. Simulation is performed in MATLAB
This document discusses the implementation of an interleaver on an FPGA for wireless communication systems. It proposes a novel finite state machine (FSM) based approach to model a multimode address generator for a WiMAX interleaver using VHDL on an FPGA. The proposed interleaver works better at high frequencies compared to existing FPGA approaches and uses minimal logic cells. It also studies interleaving techniques in OFDM-based wireless local area networks and discusses designing the interleaver using the internal memory blocks of an FPGA.
This document summarizes a research paper that proposes using parallel concatenated turbo codes in wireless sensor networks in an adaptive way. The key points are:
1) Turbo codes can achieve near-Shannon limit performance but decoding is complex, making them difficult to implement on energy-constrained sensor nodes.
2) The proposed approach shifts the complex turbo decoding to the base station while sensor nodes implement encoding and basic error correction.
3) At sensor nodes, a parallel concatenated convolutional code (PCCC) circuit encodes data and detects/corrects errors in forwarded packets. This improves energy efficiency and reliability over the wireless sensor network.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Comparative study of various voip applications in 802.11 a wireless network s...ijmnct
Today, Voice over Wireless Local Area Network (VOWLAN) is the most accepted Internet application.
There are a large number of literatures regarding the performance of various WLAN networks. Most of
them focus on simulations and modeling, but there are also some experiments with real networks. This
paper explains the comparison of performance of two different VOIP (Voice over Internet Protocol)
applications over the same IEEE 802.11a wireless network. Radio link standard 802.11a have maximum
transmission rate of 54Mbps. First protocol is session initiation protocol (SIP) and second is H.323
protocol. First one has an agent called SIP proxy. Second have a gateway reflects the characteristics of a
Switched Circuit Network (SCN). With this comparison we have required to obtain a better understanding
of wireless network suitability for voice communication in IP network.
Error Control and performance Analysis of MIMO-OFDM Over Fading ChannelsIOSR Journals
ABSTRACT: Multiple Input Multiple Output is a wireless technology that uses multiple transmitters and
receivers to transfer more data at the same time. Orthogonal Frequency Division Multiplexing, an FDM
modulation technique which splits the signal into multiple smaller sub-signals that are then transmitted
simultaneously at different frequencies to the receiver. OFDM technique spreads the data over number of
carriers which are at specific predefined frequencies. This reduces or eliminates the ISI. Forward error
correction or channel coding is a technique used for controlling errors in data transmission over unreliable or
noisy communication channels. The objective of our proposed paper is to implement the FEC into the MIMO
OFDM systems and its performance is analysed by using MATLAB over different fading channels. For
modulation it employs M-QAM which combines both ASK and PSK thereby enabling several bits to be
transmitted per symbol. The performance of MIMO-OFDM system is evaluated by BER Vs SNR when the bits
propagates through the different fading channels.
Keywords– OFDM, MIMO, QAM, FEC, BER.
Comparative study of_digital_modulation (1)Bindia Kumari
This document compares different digital modulation techniques that can be used in orthogonal frequency division multiplexing (OFDM) and WiMAX networks. It simulates BPSK, QPSK, 16-QAM and 64-QAM modulation in MATLAB and measures their performance in terms of bit error rate and throughput. The results show that higher order modulations like 64-QAM provide much higher throughput but also higher bit error rates compared to lower order modulations at a given signal-to-noise ratio. The best configuration balances low bit error rates and high throughput.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
The Performance Evaluation of IEEE 802.16 Physical Layer in the Basis of Bit ...IJCI JOURNAL
Fixed Broadband Wireless Access is a promising technology which can offer high speed data rate from transmitting end to customer end which can offer high speed text, voice, and video data. IEEE 802.16 WirelessMAN is a standard that specifies medium access control layer and a set of PHY layer to fixed and mobile BWA in broad range of frequencies and it supports equipment manufacturers due to its robust performance in multipath environment. Consequently WiMAX forum has adopted this version to develop the network world wide. In this paper the performance of IEEE 802.16 OFDM PHY Layer has been investigated by using the simulation model in Matlab. The Stanford University Interim (SUI) channel models are selected for the performance evaluation of this standard. The Ideal Channel estimation is considered in this work and the performance evaluation is observed in the basis of BER.
This document describes the design and implementation of an IP core for the CAN protocol. It begins with an introduction to CAN and its use in automotive and industrial applications. It then discusses the protocol layers, frame formats, arbitration, and error handling mechanisms of CAN. The document proceeds to describe the design of Verilog modules for a CAN transceiver including transmitter and receiver modules. It presents simulation waveforms showing the transmission and reception of CAN frames between two FPGA boards. It concludes that the IP core was successfully implemented on Spartan 3 and Spartan 6 FPGAs to demonstrate node-to-node communication over a CAN bus.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
This document compares routing protocols for ad hoc wireless networks used for transmitting medical data. It evaluates AODV, OLSR, and TORA protocols in OPNET based on throughput and delay. The simulation models a 1000m x 1000m indoor hospital environment with
Controller Area Network is an ideal serial bus design suitable for modern embedded system based networks. It finds its use in most of critical applications, where error detection and subsequent treatment on error is a critical issue. CRC (Cyclic Redundancy Check) block was developed on FPGA in order to meet the needs for simple, low power and low cost wireless communication. This paper gives a short overview of CRC block in the Digital transmitter based on the CAN 2.0 protocols. CRC is the most preferred method of encoding because it provides very efficient protection against commonly occurring burst errors, and is easily implemented. This technique is also sometimes applied to data storage devices, such as a disk drive. In this paper a technique to model the error detection circuitry of CAN 2.0 protocols on reconfigurable platform have been discussed? The software simulation results are presented in the form of timing diagram.FPGA implementation results shows that the circuitry requires very small amount of digital hardware. The Purpose of the research is to diversify the design methods by using VHDL code entry through Modelsim 5.5e simulator and Xilinx ISE8.3i.The VHDL code is used to characterize the CRC block behavior which is then simulated, synthesized and successfully implemented on Sparten3 FPGA .Here, Simulation and Synthesized results are also presented to verify the functionality of the CRC -16 Block. The data rate of CRC block is 250 kbps .Estimated power consumption and maximum operating frequency of the circuitry is also provided.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
UNIT IV WIRELESS SENSOR NETWORKS (WSNS) AND MAC PROTOCOLS 9 Single node architecture: hardware and software components of a sensor node - WSN Network architecture: typical network architectures-data relaying and aggregation strategies -MAC layer protocols: self-organizing, Hybrid TDMA/FDMA and CSMA based MAC- IEEE 802.15.4.
COMPARISON OF ROUTING PROTOCOLS FOR AD HOC WIRELESS NETWORK WITH MEDICAL DATA Zakaria Zubi
Ad Hoc wireless network that without any central controlling authority, which is a collection of mobile nodes that are dynamically and arbitrarily located in such a manner that the interconnections between nodes are capable of changing on a continual basis, so nodes cooperate to route a packet.
The purpose of the routing protocols is to discover rapid changes of the topology in such a way that intermediate nodes can act as routers to forward packets on behalf of the communicating pair .
IMPLEMENTATION OF A NEW IR-UWB SYSTEM BASED ON M-OAM MODULATION ON FPGA COMPO...ijwmn
This paper presents the implementation ofan Impulse Radio Ultra Wide Band (IR-UWB) communication system based on Orthogonal Amplitude Modulation (OAM) on the FPGA board (Field Programmable Gate Array). The Orthogonal Amplitude Modulationis a new modulation technique that provides a high data rate transmission, using the orthogonal waveforms named MGF (ModifiedGegenbaeur Function).In this work, the FPGA card and the converters DAC(Digital-to-Analog Converter) and ADC (Analog to Digital Converter) are considered to perform the implementation. The system is running in the simulation field
andin the real system on the hardware equipment.The obtained results show that the implementation of UWB-OAM system on FPGA board is running well andprovide a high - real time computations system.
Channel estimation for high data rate communication in mobile wi max systemIAEME Publication
1) The document discusses channel estimation techniques for high data rate communication in mobile WiMAX systems. It evaluates the performance of two interpolation schemes: Least Square Error (LSE) and Minimum Mean Square Error (MMSE).
2) Through simulation, it is shown that MMSE outperforms LSE, providing better bit error rate performance closer to the ideal channel condition. MMSE estimation results in symbols that are less scattered than LSE when plotted, indicating it is more robust against noise.
3) The key advantage of MMSE is that it takes into account additional information like signal to noise ratio and channel statistics, allowing it to provide smoother interpolation compared to the simpler LSE technique.
IMPLEMENTATION OF A NEW IR-UWB SYSTEM BASED ON M-OAM MODULATION ON FPGA COMPO...ijwmn
This paper presents the implementation of an Impulse Radio Ultra Wide Band (IR-UWB) communication
system based on Orthogonal Amplitude Modulation (OAM) on the FPGA board (Field Programmable Gate
Array). The Orthogonal Amplitude Modulation is a new modulation technique that provides a high data
rate transmission, using the orthogonal waveforms named MGF (ModifiedGegenbaeur Function). In this
work, the FPGA card and the converters DAC(Digital-to-Analog Converter) and ADC (Analog to Digital
Converter) are considered to perform the implementation. The system is running in the simulation field and
in the real system on the hardware equipment.The obtained results show that the implementation of UWBOAM
system on FPGA board is running well andprovide a high - real time computations system.
الأجيال المختلفه في شبكات المحمول باللغه العربيه للدكتور عبد الكريم حسين الم...ibrahimnabil17
The document provides a detailed explanation of the four generations of mobile communications including their basic concepts, components, and transmission methods. It discusses the architecture and features of 1G networks like Advanced Mobile Phone System (AMPS) and Nordic Mobile Telephony (NMT), as well as 2G networks exemplified by the Global System for Mobile Communications (GSM). The document also touches on goals and major networks of 2G and provides an introduction to 3G.
Analysis of WiMAX Physical Layer Using Spatial Multiplexing Under Different F...CSCJournals
WiMAX is defined as Worldwide Interoperability for Microwave Access by the WiMAX Forum and its industry. WiMAX is basically a wireless digital communication system which is also known as IEEE 802.16 standard intended for wireless \"metropolitan area networks\". WiMAX is based upon OFDM multiplexing technique. It was developed in order to provide high speed data rates to the users located in those areas also where broadband wireless coverage is not available. MIMO systems also play an important role in the field of wireless communication by allowing data to be transmitted and received over different antennas. WiMAX-MIMO systems are developed to improve the performance of WiMAX system. This paper analyzes WiMAX-MIMO system for different modulation schemes with different CC code rates under different fading channels (Rician and Nakagami channel). Spatial Multiplexing technique of MIMO system is used for the simulation purpose. Analysis has been done in the form of Signal-to Noise Ratio (SNR) vs Bit Error Rate (BER) plots.
Digital communication uses digital signals that have discrete states (on/off) instead of continuous amplitudes like analog signals. This allows for higher quality transmission with less noise and distortion. SDH (Synchronous Digital Hierarchy) was developed to address limitations of earlier PDH (Plesiochronous Digital Hierarchy) transmission, which used almost synchronous clocks. SDH uses a master-slave clock technique and overhead bytes to provide synchronization across nodes, manage payloads, and enable features like automatic protection switching and performance monitoring. The basic SDH frame is STM-1, which has 9 rows and 270 columns for a total of 2430 bytes transmitted every 125 microseconds at 155 Mbps. Higher STM frames are formed by multiplying the
IJERD (www.ijerd.com) International Journal of Engineering Research and Devel...IJERD Editor
The document analyzes the performance of a turbo coded WiMAX system over different communication channels, including AWGN, Rayleigh, and Rician channels. It describes the key components of the WiMAX physical layer, including randomization, forward error correction, interleaving, symbol mapping, and encoding of turbo codes. Simulation results are presented comparing the performance of the different channels, with AWGN showing better performance at higher numbers of turbo code iterations. With convolution coding alone performance was weaker, but turbo coding provided about a 7dB enhancement.
Effect of Interleaved FEC Code on Wavelet Based MC-CDMA System with Alamouti ...IJCSEIT Journal
In this paper, the impact of Forward Error Correction (FEC) code namely Trellis code with interleaver on
the performance of wavelet based MC-CDMA wireless communication system with the implementation of
Alamouti antenna diversity scheme has been investigated in terms of Bit Error Rate (BER) as a function of
Signal-to-Noise Ratio (SNR) per bit. Simulation of the system under proposed study has been done in M-ary
modulation schemes (MPSK, MQAM and DPSK) over AWGN and Rayleigh fading channel incorporating
Walsh Hadamard code as orthogonal spreading code to discriminate the message signal for individual
user. It is observed via computer simulation that the performance of the interleaved coded based proposed
system outperforms than that of the uncoded system in all modulation schemes over Rayleigh fading
channel.
This document summarizes a seminar presentation on Optical Code Division Multiple Access (OCDMA). OCDMA allows multiple users to transmit simultaneously over the same bandwidth using unique optical codes. It provides advantages over TDMA and FDMA such as supporting more users and asynchronous transmission without packet collisions. The presentation describes OCDMA network implementation using optical orthogonal codes assigned to transmitters and receivers for communication. It also discusses enhanced security provided by OCDMA through increasing the signal-to-noise ratio required for eavesdropping.
The document discusses several topics related to digital signal processing and telecommunications networks:
1) It explains why analog signals need to be converted to digital for processing by microprocessors, and describes the steps of analog to digital and digital to analog conversion.
2) It defines pulse code modulation (PCM) and its role in encoding analog signals like speech into digital signals for transmission.
3) It discusses the use of multiplexing to combine multiple signals into a single channel for transmission over networks in order to save costs.
4) It provides an overview of the OSI model and its layered approach to network communication.
Turbo codes are error-correcting codes with performance that is close to the
Shannon theoretical limit (SHA). The motivation for using turbo codes is
that the codes are an appealing mix of a random appearance on the channel
and a physically realizable decoding structure. The communication systems
have the problem of latency, fast switching, and reliable data transfer. The
objective of the research paper is to design and turbo encoder and decoder
hardware chip and analyze its performance. Two convolutional codes are
concatenated concurrently and detached by an interleaver or permuter in the
turbo encoder. The expected data from the channel is interpreted iteratively
using the two related decoders. The soft (probabilistic) data about an
individual bit of the decoded structure is passed in each cycle from one
elementary decoder to the next, and this information is updated regularly.
The performance of the chip is also verified using the maximum a posteriori
(MAP) method in the decoder chip. The performance of field-programmable
gate array (FPGA) hardware is evaluated using hardware and timing
parameters extracted from Xilinx ISE 14.7. The parallel concatenation offers
a better global rate for the same component code performance, and reduced
delay, low hardware complexity, and higher frequency support.
Performance Improvement of IEEE 802.22 WRAN Physical LayerIOSR Journals
Abstract: The spectrum available for the wireless services is limited, the increased demand of wireless application has put a lot of limitations on the utilization of available radio spectrum. For the efficient spectrum utilization for wireless application IEEE 802.22 standard i.e. WRAN (Wireless Regional Area Network) is developed which is based on cognitive radio technique that senses the free available spectrum. It allows sharing of geographically unused channels allocated to the TV Broadcast Service, without interference. In this paper we are evaluating the performance of WRAN over physical layer with QPSK, 16-QAM and 64-QAM modulation with Convolution coding with code rate of 1/2, 2/3, 3/4, 5/6 and obtaining the BER curves for rician channel. Simulation is performed in MATLAB. Keywords - CC, CP, CR, OFDMA, PHY Layer, WRAN
The Performance Evaluation of IEEE 802.16 Physical Layer in the Basis of Bit ...IJCI JOURNAL
Fixed Broadband Wireless Access is a promising technology which can offer high speed data rate from transmitting end to customer end which can offer high speed text, voice, and video data. IEEE 802.16 WirelessMAN is a standard that specifies medium access control layer and a set of PHY layer to fixed and mobile BWA in broad range of frequencies and it supports equipment manufacturers due to its robust performance in multipath environment. Consequently WiMAX forum has adopted this version to develop the network world wide. In this paper the performance of IEEE 802.16 OFDM PHY Layer has been investigated by using the simulation model in Matlab. The Stanford University Interim (SUI) channel models are selected for the performance evaluation of this standard. The Ideal Channel estimation is considered in this work and the performance evaluation is observed in the basis of BER.
This document describes the design and implementation of an IP core for the CAN protocol. It begins with an introduction to CAN and its use in automotive and industrial applications. It then discusses the protocol layers, frame formats, arbitration, and error handling mechanisms of CAN. The document proceeds to describe the design of Verilog modules for a CAN transceiver including transmitter and receiver modules. It presents simulation waveforms showing the transmission and reception of CAN frames between two FPGA boards. It concludes that the IP core was successfully implemented on Spartan 3 and Spartan 6 FPGAs to demonstrate node-to-node communication over a CAN bus.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
This document compares routing protocols for ad hoc wireless networks used for transmitting medical data. It evaluates AODV, OLSR, and TORA protocols in OPNET based on throughput and delay. The simulation models a 1000m x 1000m indoor hospital environment with
Controller Area Network is an ideal serial bus design suitable for modern embedded system based networks. It finds its use in most of critical applications, where error detection and subsequent treatment on error is a critical issue. CRC (Cyclic Redundancy Check) block was developed on FPGA in order to meet the needs for simple, low power and low cost wireless communication. This paper gives a short overview of CRC block in the Digital transmitter based on the CAN 2.0 protocols. CRC is the most preferred method of encoding because it provides very efficient protection against commonly occurring burst errors, and is easily implemented. This technique is also sometimes applied to data storage devices, such as a disk drive. In this paper a technique to model the error detection circuitry of CAN 2.0 protocols on reconfigurable platform have been discussed? The software simulation results are presented in the form of timing diagram.FPGA implementation results shows that the circuitry requires very small amount of digital hardware. The Purpose of the research is to diversify the design methods by using VHDL code entry through Modelsim 5.5e simulator and Xilinx ISE8.3i.The VHDL code is used to characterize the CRC block behavior which is then simulated, synthesized and successfully implemented on Sparten3 FPGA .Here, Simulation and Synthesized results are also presented to verify the functionality of the CRC -16 Block. The data rate of CRC block is 250 kbps .Estimated power consumption and maximum operating frequency of the circuitry is also provided.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
UNIT IV WIRELESS SENSOR NETWORKS (WSNS) AND MAC PROTOCOLS 9 Single node architecture: hardware and software components of a sensor node - WSN Network architecture: typical network architectures-data relaying and aggregation strategies -MAC layer protocols: self-organizing, Hybrid TDMA/FDMA and CSMA based MAC- IEEE 802.15.4.
COMPARISON OF ROUTING PROTOCOLS FOR AD HOC WIRELESS NETWORK WITH MEDICAL DATA Zakaria Zubi
Ad Hoc wireless network that without any central controlling authority, which is a collection of mobile nodes that are dynamically and arbitrarily located in such a manner that the interconnections between nodes are capable of changing on a continual basis, so nodes cooperate to route a packet.
The purpose of the routing protocols is to discover rapid changes of the topology in such a way that intermediate nodes can act as routers to forward packets on behalf of the communicating pair .
IMPLEMENTATION OF A NEW IR-UWB SYSTEM BASED ON M-OAM MODULATION ON FPGA COMPO...ijwmn
This paper presents the implementation ofan Impulse Radio Ultra Wide Band (IR-UWB) communication system based on Orthogonal Amplitude Modulation (OAM) on the FPGA board (Field Programmable Gate Array). The Orthogonal Amplitude Modulationis a new modulation technique that provides a high data rate transmission, using the orthogonal waveforms named MGF (ModifiedGegenbaeur Function).In this work, the FPGA card and the converters DAC(Digital-to-Analog Converter) and ADC (Analog to Digital Converter) are considered to perform the implementation. The system is running in the simulation field
andin the real system on the hardware equipment.The obtained results show that the implementation of UWB-OAM system on FPGA board is running well andprovide a high - real time computations system.
Channel estimation for high data rate communication in mobile wi max systemIAEME Publication
1) The document discusses channel estimation techniques for high data rate communication in mobile WiMAX systems. It evaluates the performance of two interpolation schemes: Least Square Error (LSE) and Minimum Mean Square Error (MMSE).
2) Through simulation, it is shown that MMSE outperforms LSE, providing better bit error rate performance closer to the ideal channel condition. MMSE estimation results in symbols that are less scattered than LSE when plotted, indicating it is more robust against noise.
3) The key advantage of MMSE is that it takes into account additional information like signal to noise ratio and channel statistics, allowing it to provide smoother interpolation compared to the simpler LSE technique.
IMPLEMENTATION OF A NEW IR-UWB SYSTEM BASED ON M-OAM MODULATION ON FPGA COMPO...ijwmn
This paper presents the implementation of an Impulse Radio Ultra Wide Band (IR-UWB) communication
system based on Orthogonal Amplitude Modulation (OAM) on the FPGA board (Field Programmable Gate
Array). The Orthogonal Amplitude Modulation is a new modulation technique that provides a high data
rate transmission, using the orthogonal waveforms named MGF (ModifiedGegenbaeur Function). In this
work, the FPGA card and the converters DAC(Digital-to-Analog Converter) and ADC (Analog to Digital
Converter) are considered to perform the implementation. The system is running in the simulation field and
in the real system on the hardware equipment.The obtained results show that the implementation of UWBOAM
system on FPGA board is running well andprovide a high - real time computations system.
الأجيال المختلفه في شبكات المحمول باللغه العربيه للدكتور عبد الكريم حسين الم...ibrahimnabil17
The document provides a detailed explanation of the four generations of mobile communications including their basic concepts, components, and transmission methods. It discusses the architecture and features of 1G networks like Advanced Mobile Phone System (AMPS) and Nordic Mobile Telephony (NMT), as well as 2G networks exemplified by the Global System for Mobile Communications (GSM). The document also touches on goals and major networks of 2G and provides an introduction to 3G.
Analysis of WiMAX Physical Layer Using Spatial Multiplexing Under Different F...CSCJournals
WiMAX is defined as Worldwide Interoperability for Microwave Access by the WiMAX Forum and its industry. WiMAX is basically a wireless digital communication system which is also known as IEEE 802.16 standard intended for wireless \"metropolitan area networks\". WiMAX is based upon OFDM multiplexing technique. It was developed in order to provide high speed data rates to the users located in those areas also where broadband wireless coverage is not available. MIMO systems also play an important role in the field of wireless communication by allowing data to be transmitted and received over different antennas. WiMAX-MIMO systems are developed to improve the performance of WiMAX system. This paper analyzes WiMAX-MIMO system for different modulation schemes with different CC code rates under different fading channels (Rician and Nakagami channel). Spatial Multiplexing technique of MIMO system is used for the simulation purpose. Analysis has been done in the form of Signal-to Noise Ratio (SNR) vs Bit Error Rate (BER) plots.
Digital communication uses digital signals that have discrete states (on/off) instead of continuous amplitudes like analog signals. This allows for higher quality transmission with less noise and distortion. SDH (Synchronous Digital Hierarchy) was developed to address limitations of earlier PDH (Plesiochronous Digital Hierarchy) transmission, which used almost synchronous clocks. SDH uses a master-slave clock technique and overhead bytes to provide synchronization across nodes, manage payloads, and enable features like automatic protection switching and performance monitoring. The basic SDH frame is STM-1, which has 9 rows and 270 columns for a total of 2430 bytes transmitted every 125 microseconds at 155 Mbps. Higher STM frames are formed by multiplying the
IJERD (www.ijerd.com) International Journal of Engineering Research and Devel...IJERD Editor
The document analyzes the performance of a turbo coded WiMAX system over different communication channels, including AWGN, Rayleigh, and Rician channels. It describes the key components of the WiMAX physical layer, including randomization, forward error correction, interleaving, symbol mapping, and encoding of turbo codes. Simulation results are presented comparing the performance of the different channels, with AWGN showing better performance at higher numbers of turbo code iterations. With convolution coding alone performance was weaker, but turbo coding provided about a 7dB enhancement.
Effect of Interleaved FEC Code on Wavelet Based MC-CDMA System with Alamouti ...IJCSEIT Journal
In this paper, the impact of Forward Error Correction (FEC) code namely Trellis code with interleaver on
the performance of wavelet based MC-CDMA wireless communication system with the implementation of
Alamouti antenna diversity scheme has been investigated in terms of Bit Error Rate (BER) as a function of
Signal-to-Noise Ratio (SNR) per bit. Simulation of the system under proposed study has been done in M-ary
modulation schemes (MPSK, MQAM and DPSK) over AWGN and Rayleigh fading channel incorporating
Walsh Hadamard code as orthogonal spreading code to discriminate the message signal for individual
user. It is observed via computer simulation that the performance of the interleaved coded based proposed
system outperforms than that of the uncoded system in all modulation schemes over Rayleigh fading
channel.
This document summarizes a seminar presentation on Optical Code Division Multiple Access (OCDMA). OCDMA allows multiple users to transmit simultaneously over the same bandwidth using unique optical codes. It provides advantages over TDMA and FDMA such as supporting more users and asynchronous transmission without packet collisions. The presentation describes OCDMA network implementation using optical orthogonal codes assigned to transmitters and receivers for communication. It also discusses enhanced security provided by OCDMA through increasing the signal-to-noise ratio required for eavesdropping.
The document discusses several topics related to digital signal processing and telecommunications networks:
1) It explains why analog signals need to be converted to digital for processing by microprocessors, and describes the steps of analog to digital and digital to analog conversion.
2) It defines pulse code modulation (PCM) and its role in encoding analog signals like speech into digital signals for transmission.
3) It discusses the use of multiplexing to combine multiple signals into a single channel for transmission over networks in order to save costs.
4) It provides an overview of the OSI model and its layered approach to network communication.
Turbo codes are error-correcting codes with performance that is close to the
Shannon theoretical limit (SHA). The motivation for using turbo codes is
that the codes are an appealing mix of a random appearance on the channel
and a physically realizable decoding structure. The communication systems
have the problem of latency, fast switching, and reliable data transfer. The
objective of the research paper is to design and turbo encoder and decoder
hardware chip and analyze its performance. Two convolutional codes are
concatenated concurrently and detached by an interleaver or permuter in the
turbo encoder. The expected data from the channel is interpreted iteratively
using the two related decoders. The soft (probabilistic) data about an
individual bit of the decoded structure is passed in each cycle from one
elementary decoder to the next, and this information is updated regularly.
The performance of the chip is also verified using the maximum a posteriori
(MAP) method in the decoder chip. The performance of field-programmable
gate array (FPGA) hardware is evaluated using hardware and timing
parameters extracted from Xilinx ISE 14.7. The parallel concatenation offers
a better global rate for the same component code performance, and reduced
delay, low hardware complexity, and higher frequency support.
Performance Improvement of IEEE 802.22 WRAN Physical LayerIOSR Journals
Abstract: The spectrum available for the wireless services is limited, the increased demand of wireless application has put a lot of limitations on the utilization of available radio spectrum. For the efficient spectrum utilization for wireless application IEEE 802.22 standard i.e. WRAN (Wireless Regional Area Network) is developed which is based on cognitive radio technique that senses the free available spectrum. It allows sharing of geographically unused channels allocated to the TV Broadcast Service, without interference. In this paper we are evaluating the performance of WRAN over physical layer with QPSK, 16-QAM and 64-QAM modulation with Convolution coding with code rate of 1/2, 2/3, 3/4, 5/6 and obtaining the BER curves for rician channel. Simulation is performed in MATLAB. Keywords - CC, CP, CR, OFDMA, PHY Layer, WRAN
Performance Improvement of IEEE 802.22 WRAN Physical LayerIOSR Journals
Abstract: The spectrum available for the wireless services is limited, the increased demand of wireless
application has put a lot of limitations on the utilization of available radio spectrum. For the efficient spectrum
utilization for wireless application IEEE 802.22 standard i.e. WRAN (Wireless Regional Area Network) is
developed which is based on cognitive radio technique that senses the free available spectrum. It allows sharing
of geographically unused channels allocated to the TV Broadcast Service, without interference.
In this paper we are evaluating the performance of WRAN over physical layer with QPSK, 16-QAM
and 64-QAM modulation with Convolution coding with code rate of 1/2, 2/3, 3/4, 5/6 and obtaining the BER
curves for rician channel. Simulation is performed in MATLAB.
Keywords - CC, CP, CR, OFDMA, PHY Layer, WRAN
Iterative network channel decoding with cooperative space-time transmissionijasuc
This document summarizes an iterative network-channel decoding scheme for cooperative space-time transmission with network coding. The scheme uses convolutional codes as network codes at the relay node and Reed-Solomon codes as channel codes at the user nodes. An iterative joint network-channel decoder exchanges soft information between convolutional code-based network decoder and Reed-Solomon code-based channel decoders. Extrinsic information transfer analysis is performed to investigate the convergence properties of the proposed iterative decoder.
This document discusses implementing security and steganography in 802.11n networks. It proposes hiding information in the cyclic prefix of OFDM symbols. Modifying the cyclic prefix does not require additional bandwidth and increases the potential hidden transmission capacity depending on the modulation scheme. Simulation results show the steganographic system does not increase costs for ordinary users and security is improved by using private keys to randomly select modified symbols.
Iaetsd ber performance of cdma, wcdma, ieee802.11g in awgnIaetsd Iaetsd
This document discusses and compares the bit error rate (BER) performance of CDMA, WCDMA, and IEEE 802.11g wireless standards in additive white Gaussian noise (AWGN) and fading channels. It proposes an integrated low power code synchronizer for these three standards using techniques like power management, absolute weighted magnitude calculation, and spurious power suppression in the adders. Simulation results show that the proposed techniques reduce power consumption in the correlator element array, especially for WCDMA in AWGN channels where power is reduced by half. Fading channels generally consume less power than AWGN channels.
Team D1Team D Modulation ApplicationsMay1, 2015.docxmattinsonjanel
Team D 1
Team D Modulation Applications
May1, 2015
Aslam Modak
NTC/362
Modulation Applications
There are several variances between analog and digital transmission technologies and it is crucial to comprehend how conversions between the two technologies occur. An analog signal is describe as being constantly variable along amplitudes and frequencies. On the other hand, digital transmissions is very different from its analog transmissions. One difference is the signal is considerable simpler. Rather than being constantly a variable wave form, it is a series of separate pulses that represent one and zeros. As for example, each computer utilizes a coding scheme that outlines what arrangement of ones and zeros create all characters in a character set, which includes upper and lower case letters, special characters, and keyboard control functions (Goleniewski, 2015). Furthermore, there are many technologies covert the two signals on both directions, meaning analog-to-digital and digital-to-analog. This is the case of a two converters DAC and ADC technologies. An ADC is the device that coverts or transforms a continuous physical quantity (voltage) to a digital number that presents the quantity’s amplitude. ADCs covers digital data into an analog signal such as a current or voltage. These converters are found on most electronic devices that plug to the electric outlet. They are microchips integrated on the circuit board of the electronic device.
There are several types of modulation applications. These applications are amplitude, frequency, phase and QAM modulation. They all serve different but important purposes. Along with these purposes there are also advantages and disadvantages.
Amplitude modulation (AM) is used in a variety of applications. Although use of the modulation is not relied upon currently as it was used in the past, you can still find it in its basic form. When an AM modulated signal is created, the amplitude of the signal is varied in line with the variations in intensity of the sound wave. AM is the most straightforward way of modulating a signal. Some of the advantages are, it is simple to implement, an AM signal is efficient in terms of its power usage, and it can be demodulated using a circuit consisting of a very few components. Disadvantages are AM signals are prone to high levels of noise because most noise is amplitude based and AM detectors are sensitive to it.
Frequency Modulation (FM) is used in a wide variety or radio communication applications from broadcasting, two way radio communications links, and mobile radio communications. It possesses many advantages over AM. For example, it is resilient to noise. FM that has been utilized by the broadcasting industry is the reduction in noise. FM Does not require linear amplifiers in the transmitter. Disadvantages are it requires more complicated demodulator. Some other modes have higher data spectral efficiency.
Phase Modulation (PM) is a form of modulati ...
This document summarizes a research paper that analyzes the performance of various digital filters in an OCDMA (Optical Code Division Multiple Access) multi-user environment using 3D codes. The document describes a simulation of a 24-user OCDMA system using different parameters like BER (Bit Error Rate), Q-factor, and eye patterns with filters including Raised Cosine, Gaussian, Fabry Perot, Trapezoidal, and Lorentzian. The analysis found that the system using a Fabry Perot filter had the minimum distortion while maintaining a low BER of 6.81×e-20 for correctly decoded signals.
Performance evaluation of VLC system using new modulation approachjournalBEEI
This document evaluates the performance of a new modulation scheme called catenated-OFDM for visible light communications (VLC) systems. Catenated-OFDM involves transmitting multiple OFDM signals simultaneously over different optical bands. The proposed system is simulated using Optisys software. Results show the system can achieve transmission distances of up to 12 meters for 2 dBm input power with 3 optical bands and a data rate of 10 Gbps. Higher data rates, up to 15 Gbps, are also possible. Increasing the number of optical bands or decreasing the data rate improves the receiver sensitivity. The catenated-OFDM approach shows potential for high-speed optical wireless communications.
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
ESTIMATION AND COMPENSATION OF INTER CARRIER INTERFERENCE IN WIMAX PHYSICAL L...ijngnjournal
WiMAX is Wireless Interoperability for Microwave Access has emerged as a promising solution for transmission of higher data rates for fixed and mobile applications. IEEE 802.16d and e are the standards proposed by WiMAX group for fixed and mobile. As the wireless channel have so many limitation Such as Multipath, Doppler spread, Delay spread and Line Of Sight (LOS)/Non Line Of Sight (NLOS) components. To attain higher data rates the Multi Carrier System with Multiple Input and Multiple Output (MIMO) is incorporated in the WiMAX. The Orthogonal Frequency Division Multiplexing (OFDM) is a multi carrier technique used with the WiMAX systems. In OFDM the available spectrum is split into numerous narrow band channels of dissimilar frequencies to achieve high data rate in a multi path fading environment. And all these sub carriers are considered to be orthogonal to each other. As the number of sub carriers is increased there is no guarantee of sustained orthogonality, i.e. at some point the carriers are not
independent to each other, and hence where the orthogonality can be loosed which leads to interference and also owing to the synchronization between transmitter and receiver local oscillator, it causes interference known as Inter Carrier Interference (ICI). The systems uses MIMO-OFDM will suffer with the effects of ICI and Carrier Frequency Offset (CFO) “ε”. However these affect the power leakage in the midst of sub carriers, consequently degrading the system performance. In this paper a new approach is proposed in order to reduce the ICI caused in WiMAX and improve the system performance. In this scheme at the transmitter side the modulated data and a few predefined pilot symbols are mapped onto the non
neighboring sub carriers with weighting coefficients of +1 and -1. With the aid of pilot symbols the frequency offset is exactly estimated by using Maximum Likelihood Estimation (MLE) and hence can be minimized. At demodulation stage the received signals are linearly combined along with their weighted
coefficients and pilot symbols, called as Pilot Aided Self Cancellation Method (PASCS). And also to realize the various wireless environments the simulations are carried out on Stanford University Interim (SUI) channels. The simulation results shows that by incorporating this method into WiMAX systems it performs better when the Line Of Sight (LOS) component is present in the transmission and also it improves the Bit Error Rate (BER) and Carrier to Interference Ratio (CIR). The CIR can be improved 20 dB. In this paper the effectiveness of PASCS scheme is compared with the Self Cancellation Method (SCM). It provides accurate estimation of frequency offset and when residual CFO is less significant the ICI can be diminished successfully.
This document describes a space-time block coding (STBC) orthogonal frequency-division multiplexing (OFDM) system for text message transmission over fading channels using multiple transmit antennas. It evaluates the bit error rate (BER) performance of the system using different digital modulation schemes (BPSK, QPSK, QAM-8) over additive white Gaussian noise (AWGN) channels and fading channels. Low-density parity-check (LDPC) coding is concatenated with convolutional coding in the system to improve error performance. Simulation results show that the system is effective in retrieving the transmitted text message under noise and fading conditions, and that BER performance degrades with increasing noise power as expected.
This document summarizes a research paper that proposes a space-time block coded (STBC) orthogonal frequency-division multiplexing (OFDM) system for text message transmission over fading channels using multiple transmit antennas. The system utilizes low-density parity-check channel coding concatenated with convolutional coding. Simulation results show that the proposed system achieves good error rate performance, especially when using BPSK modulation with 2x4 transmit antennas in AWGN, Rayleigh, and Rician fading channels. The system is effective in properly identifying and retrieving transmitted text messages in noisy and fading environments.
IRJET- Power Line Carrier CommunicationIRJET Journal
This document describes power line carrier communication (PLCC), which uses power lines as a communication medium. It discusses using PLCC to transmit electricity billing data from individual homes to the electricity company without site visits. Key components of the system include a real-time clock, energy meter, microcontroller, LCD display, and FSK transmitter and receiver. Data transmission is done by modulating a signal onto the power line using FSK modulation. The system is intended to reduce the burden on electricity companies by allowing remote transmission of billing data without the need for site visits.
Giga bit per second Differential Scheme for High Speed InterconnectVLSICS Design
This document summarizes a research paper on developing a high-speed transmitter for off-chip communication using differential signaling. It describes a transmitter circuit that consists of low-speed input buffers, serializers to convert parallel data to serial data, and current-mode drivers to transmit the serial data differentially over transmission lines. The serializers use a delay locked loop to generate clock phases that sample the parallel inputs and transmit each bit over the serial link for an equal duration. The current-mode drivers convert the serial data to differential current levels on the transmission line. The design is intended to increase I/O bandwidth for high-speed chip-to-chip communication.
1. The document presents a simulation of a low power analog channel decoder for error correction implemented in 65nm CMOS technology.
2. The decoder uses analog circuitry operating in the sub-threshold region to perform decoding, allowing for ultra-low power operation below 40uW for throughput up to 2.5Mbps.
3. The decoder architecture includes an analog decoding core that implements the sum-product algorithm, digital interfaces for input and output, and a digital controller to manage timing.
IOSR Journal of Electronics and Communication Engineering(IOSR-JECE) is an open access international journal that provides rapid publication (within a month) of articles in all areas of electronics and communication engineering and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in electronics and communication engineering. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
Project Report on Optical Fiber Cables and Systems (MTNL Mumbai)Pradeep Singh
This document provides a summary of a project report on optical fiber cables and systems used by MTNL Mumbai. It discusses the basic optical fiber transmission system including digital distribution frames, multiplexers, optical line terminating units, and repeaters. It also covers topics like Pulse Code Modulation (PCM), digital transmission hierarchies including Synchronous Digital Hierarchy (SDH), data circuits, Dense Wavelength Division Multiplexing (DWDM), and the construction, maintenance and fault detection of optical fiber cables. Network elements of SDH like terminal multiplexers, add/drop multiplexers, and digital cross-connects are also described.
Similar to OPTICAL SWITCHING CONTROLLER USING FPGA AS A CONTROLLER FOR OCDMA ENCODER SYSTEM (20)
Text Mining in Digital Libraries using OKAPI BM25 ModelEditor IJCATR
The emergence of the internet has made vast amounts of information available and easily accessible online. As a result, most libraries have digitized their content in order to remain relevant to their users and to keep pace with the advancement of the internet. However, these digital libraries have been criticized for using inefficient information retrieval models that do not perform relevance ranking to the retrieved results. This paper proposed the use of OKAPI BM25 model in text mining so as means of improving relevance ranking of digital libraries. Okapi BM25 model was selected because it is a probability-based relevance ranking algorithm. A case study research was conducted and the model design was based on information retrieval processes. The performance of Boolean, vector space, and Okapi BM25 models was compared for data retrieval. Relevant ranked documents were retrieved and displayed at the OPAC framework search page. The results revealed that Okapi BM 25 outperformed Boolean model and Vector Space model. Therefore, this paper proposes the use of Okapi BM25 model to reward terms according to their relative frequencies in a document so as to improve the performance of text mining in digital libraries.
Green Computing, eco trends, climate change, e-waste and eco-friendlyEditor IJCATR
This document discusses green computing practices and sustainable IT services. It provides an overview of factors driving adoption of green computing to reduce costs and environmental impact of data centers, such as rising energy costs and density. Green strategies discussed include improving infrastructure efficiency, power management, thermal management, efficient product design, and virtualization to optimize resource utilization. The document examines how green computing aims to lower costs and environmental footprint, and how sustainable IT services take a broader approach considering economic, environmental and social impacts.
Policies for Green Computing and E-Waste in NigeriaEditor IJCATR
Computers today are an integral part of individuals’ lives all around the world, but unfortunately these devices are toxic to the environment given the materials used, their limited battery life and technological obsolescence. Individuals are concerned about the hazardous materials ever present in computers, even if the importance of various attributes differs, and that a more environment -friendly attitude can be obtained through exposure to educational materials. In this paper, we aim to delineate the problem of e-waste in Nigeria and highlight a series of measures and the advantage they herald for our country and propose a series of action steps to develop in these areas further. It is possible for Nigeria to have an immediate economic stimulus and job creation while moving quickly to abide by the requirements of climate change legislation and energy efficiency directives. The costs of implementing energy efficiency and renewable energy measures are minimal as they are not cash expenditures but rather investments paid back by future, continuous energy savings.
Performance Evaluation of VANETs for Evaluating Node Stability in Dynamic Sce...Editor IJCATR
Vehicular ad hoc networks (VANETs) are a favorable area of exploration which empowers the interconnection amid the movable vehicles and between transportable units (vehicles) and road side units (RSU). In Vehicular Ad Hoc Networks (VANETs), mobile vehicles can be organized into assemblage to promote interconnection links. The assemblage arrangement according to dimensions and geographical extend has serious influence on attribute of interaction .Vehicular ad hoc networks (VANETs) are subclass of mobile Ad-hoc network involving more complex mobility patterns. Because of mobility the topology changes very frequently. This raises a number of technical challenges including the stability of the network .There is a need for assemblage configuration leading to more stable realistic network. The paper provides investigation of various simulation scenarios in which cluster using k-means algorithm are generated and their numbers are varied to find the more stable configuration in real scenario of road.
Optimum Location of DG Units Considering Operation ConditionsEditor IJCATR
The optimal sizing and placement of Distributed Generation units (DG) are becoming very attractive to researchers these days. In this paper a two stage approach has been used for allocation and sizing of DGs in distribution system with time varying load model. The strategic placement of DGs can help in reducing energy losses and improving voltage profile. The proposed work discusses time varying loads that can be useful for selecting the location and optimizing DG operation. The method has the potential to be used for integrating the available DGs by identifying the best locations in a power system. The proposed method has been demonstrated on 9-bus test system.
Analysis of Comparison of Fuzzy Knn, C4.5 Algorithm, and Naïve Bayes Classifi...Editor IJCATR
Early detection of diabetes mellitus (DM) can prevent or inhibit complication. There are several laboratory test that must be done to detect DM. The result of this laboratory test then converted into data training. Data training used in this study generated from UCI Pima Database with 6 attributes that were used to classify positive or negative diabetes. There are various classification methods that are commonly used, and in this study three of them were compared, which were fuzzy KNN, C4.5 algorithm and Naïve Bayes Classifier (NBC) with one identical case. The objective of this study was to create software to classify DM using tested methods and compared the three methods based on accuracy, precision, and recall. The results showed that the best method was Fuzzy KNN with average and maximum accuracy reached 96% and 98%, respectively. In second place, NBC method had respective average and maximum accuracy of 87.5% and 90%. Lastly, C4.5 algorithm had average and maximum accuracy of 79.5% and 86%, respectively.
Web Scraping for Estimating new Record from Source SiteEditor IJCATR
Study in the Competitive field of Intelligent, and studies in the field of Web Scraping, have a symbiotic relationship mutualism. In the information age today, the website serves as a main source. The research focus is on how to get data from websites and how to slow down the intensity of the download. The problem that arises is the website sources are autonomous so that vulnerable changes the structure of the content at any time. The next problem is the system intrusion detection snort installed on the server to detect bot crawler. So the researchers propose the use of the methods of Mining Data Records and the method of Exponential Smoothing so that adaptive to changes in the structure of the content and do a browse or fetch automatically follow the pattern of the occurrences of the news. The results of the tests, with the threshold 0.3 for MDR and similarity threshold score 0.65 for STM, using recall and precision values produce f-measure average 92.6%. While the results of the tests of the exponential estimation smoothing using ? = 0.5 produces MAE 18.2 datarecord duplicate. It slowed down to 3.6 datarecord from 21.8 datarecord results schedule download/fetch fix in an average time of occurrence news.
Evaluating Semantic Similarity between Biomedical Concepts/Classes through S...Editor IJCATR
Most of the existing semantic similarity measures that use ontology structure as their primary source can measure semantic similarity between concepts/classes using single ontology. The ontology-based semantic similarity techniques such as structure-based semantic similarity techniques (Path Length Measure, Wu and Palmer’s Measure, and Leacock and Chodorow’s measure), information content-based similarity techniques (Resnik’s measure, Lin’s measure), and biomedical domain ontology techniques (Al-Mubaid and Nguyen’s measure (SimDist)) were evaluated relative to human experts’ ratings, and compared on sets of concepts using the ICD-10 “V1.0” terminology within the UMLS. The experimental results validate the efficiency of the SemDist technique in single ontology, and demonstrate that SemDist semantic similarity techniques, compared with the existing techniques, gives the best overall results of correlation with experts’ ratings.
Semantic Similarity Measures between Terms in the Biomedical Domain within f...Editor IJCATR
The techniques and tests are tools used to define how measure the goodness of ontology or its resources. The similarity between biomedical classes/concepts is an important task for the biomedical information extraction and knowledge discovery. However, most of the semantic similarity techniques can be adopted to be used in the biomedical domain (UMLS). Many experiments have been conducted to check the applicability of these measures. In this paper, we investigate to measure semantic similarity between two terms within single ontology or multiple ontologies in ICD-10 “V1.0” as primary source, and compare my results to human experts score by correlation coefficient.
A Strategy for Improving the Performance of Small Files in Openstack Swift Editor IJCATR
This is an effective way to improve the storage access performance of small files in Openstack Swift by adding an aggregate storage module. Because Swift will lead to too much disk operation when querying metadata, the transfer performance of plenty of small files is low. In this paper, we propose an aggregated storage strategy (ASS), and implement it in Swift. ASS comprises two parts which include merge storage and index storage. At the first stage, ASS arranges the write request queue in chronological order, and then stores objects in volumes. These volumes are large files that are stored in Swift actually. During the short encounter time, the object-to-volume mapping information is stored in Key-Value store at the second stage. The experimental results show that the ASS can effectively improve Swift's small file transfer performance.
Integrated System for Vehicle Clearance and RegistrationEditor IJCATR
Efficient management and control of government's cash resources rely on government banking arrangements. Nigeria, like many low income countries, employed fragmented systems in handling government receipts and payments. Later in 2016, Nigeria implemented a unified structure as recommended by the IMF, where all government funds are collected in one account would reduce borrowing costs, extend credit and improve government's fiscal policy among other benefits to government. This situation motivated us to embark on this research to design and implement an integrated system for vehicle clearance and registration. This system complies with the new Treasury Single Account policy to enable proper interaction and collaboration among five different level agencies (NCS, FRSC, SBIR, VIO and NPF) saddled with vehicular administration and activities in Nigeria. Since the system is web based, Object Oriented Hypermedia Design Methodology (OOHDM) is used. Tools such as Php, JavaScript, css, html, AJAX and other web development technologies were used. The result is a web based system that gives proper information about a vehicle starting from the exact date of importation to registration and renewal of licensing. Vehicle owner information, custom duty information, plate number registration details, etc. will also be efficiently retrieved from the system by any of the agencies without contacting the other agency at any point in time. Also number plate will no longer be the only means of vehicle identification as it is presently the case in Nigeria, because the unified system will automatically generate and assigned a Unique Vehicle Identification Pin Number (UVIPN) on payment of duty in the system to the vehicle and the UVIPN will be linked to the various agencies in the management information system.
Assessment of the Efficiency of Customer Order Management System: A Case Stu...Editor IJCATR
The Supermarket Management System deals with the automation of buying and selling of good and services. It includes both sales and purchase of items. The project Supermarket Management System is to be developed with the objective of making the system reliable, easier, fast, and more informative.
Energy-Aware Routing in Wireless Sensor Network Using Modified Bi-Directional A*Editor IJCATR
Energy is a key component in the Wireless Sensor Network (WSN)[1]. The system will not be able to run according to its function without the availability of adequate power units. One of the characteristics of wireless sensor network is Limitation energy[2]. A lot of research has been done to develop strategies to overcome this problem. One of them is clustering technique. The popular clustering technique is Low Energy Adaptive Clustering Hierarchy (LEACH)[3]. In LEACH, clustering techniques are used to determine Cluster Head (CH), which will then be assigned to forward packets to Base Station (BS). In this research, we propose other clustering techniques, which utilize the Social Network Analysis approach theory of Betweeness Centrality (BC) which will then be implemented in the Setup phase. While in the Steady-State phase, one of the heuristic searching algorithms, Modified Bi-Directional A* (MBDA *) is implemented. The experiment was performed deploy 100 nodes statically in the 100x100 area, with one Base Station at coordinates (50,50). To find out the reliability of the system, the experiment to do in 5000 rounds. The performance of the designed routing protocol strategy will be tested based on network lifetime, throughput, and residual energy. The results show that BC-MBDA * is better than LEACH. This is influenced by the ways of working LEACH in determining the CH that is dynamic, which is always changing in every data transmission process. This will result in the use of energy, because they always doing any computation to determine CH in every transmission process. In contrast to BC-MBDA *, CH is statically determined, so it can decrease energy usage.
Security in Software Defined Networks (SDN): Challenges and Research Opportun...Editor IJCATR
In networks, the rapidly changing traffic patterns of search engines, Internet of Things (IoT) devices, Big Data and data centers has thrown up new challenges for legacy; existing networks; and prompted the need for a more intelligent and innovative way to dynamically manage traffic and allocate limited network resources. Software Defined Network (SDN) which decouples the control plane from the data plane through network vitalizations aims to address these challenges. This paper has explored the SDN architecture and its implementation with the OpenFlow protocol. It has also assessed some of its benefits over traditional network architectures, security concerns and how it can be addressed in future research and related works in emerging economies such as Nigeria.
Measure the Similarity of Complaint Document Using Cosine Similarity Based on...Editor IJCATR
Report handling on "LAPOR!" (Laporan, Aspirasi dan Pengaduan Online Rakyat) system depending on the system administrator who manually reads every incoming report [3]. Read manually can lead to errors in handling complaints [4] if the data flow is huge and grows rapidly, it needs at least three days to prepare a confirmation and it sensitive to inconsistencies [3]. In this study, the authors propose a model that can measure the identities of the Query (Incoming) with Document (Archive). The authors employed Class-Based Indexing term weighting scheme, and Cosine Similarities to analyse document similarities. CoSimTFIDF, CoSimTFICF and CoSimTFIDFICF values used in classification as feature for K-Nearest Neighbour (K-NN) classifier. The optimum result evaluation is pre-processing employ 75% of training data ratio and 25% of test data with CoSimTFIDF feature. It deliver a high accuracy 84%. The k = 5 value obtain high accuracy 84.12%
Hangul Recognition Using Support Vector MachineEditor IJCATR
The recognition of Hangul Image is more difficult compared with that of Latin. It could be recognized from the structural arrangement. Hangul is arranged from two dimensions while Latin is only from the left to the right. The current research creates a system to convert Hangul image into Latin text in order to use it as a learning material on reading Hangul. In general, image recognition system is divided into three steps. The first step is preprocessing, which includes binarization, segmentation through connected component-labeling method, and thinning with Zhang Suen to decrease some pattern information. The second is receiving the feature from every single image, whose identification process is done through chain code method. The third is recognizing the process using Support Vector Machine (SVM) with some kernels. It works through letter image and Hangul word recognition. It consists of 34 letters, each of which has 15 different patterns. The whole patterns are 510, divided into 3 data scenarios. The highest result achieved is 94,7% using SVM kernel polynomial and radial basis function. The level of recognition result is influenced by many trained data. Whilst the recognition process of Hangul word applies to the type 2 Hangul word with 6 different patterns. The difference of these patterns appears from the change of the font type. The chosen fonts for data training are such as Batang, Dotum, Gaeul, Gulim, Malgun Gothic. Arial Unicode MS is used to test the data. The lowest accuracy is achieved through the use of SVM kernel radial basis function, which is 69%. The same result, 72 %, is given by the SVM kernel linear and polynomial.
Application of 3D Printing in EducationEditor IJCATR
This paper provides a review of literature concerning the application of 3D printing in the education system. The review identifies that 3D Printing is being applied across the Educational levels [1] as well as in Libraries, Laboratories, and Distance education systems. The review also finds that 3D Printing is being used to teach both students and trainers about 3D Printing and to develop 3D Printing skills.
Survey on Energy-Efficient Routing Algorithms for Underwater Wireless Sensor ...Editor IJCATR
In underwater environment, for retrieval of information the routing mechanism is used. In routing mechanism there are three to four types of nodes are used, one is sink node which is deployed on the water surface and can collect the information, courier/super/AUV or dolphin powerful nodes are deployed in the middle of the water for forwarding the packets, ordinary nodes are also forwarder nodes which can be deployed from bottom to surface of the water and source nodes are deployed at the seabed which can extract the valuable information from the bottom of the sea. In underwater environment the battery power of the nodes is limited and that power can be enhanced through better selection of the routing algorithm. This paper focuses the energy-efficient routing algorithms for their routing mechanisms to prolong the battery power of the nodes. This paper also focuses the performance analysis of the energy-efficient algorithms under which we can examine the better performance of the route selection mechanism which can prolong the battery power of the node
Comparative analysis on Void Node Removal Routing algorithms for Underwater W...Editor IJCATR
The designing of routing algorithms faces many challenges in underwater environment like: propagation delay, acoustic channel behaviour, limited bandwidth, high bit error rate, limited battery power, underwater pressure, node mobility, localization 3D deployment, and underwater obstacles (voids). This paper focuses the underwater voids which affects the overall performance of the entire network. The majority of the researchers have used the better approaches for removal of voids through alternate path selection mechanism but still research needs improvement. This paper also focuses the architecture and its operation through merits and demerits of the existing algorithms. This research article further focuses the analytical method of the performance analysis of existing algorithms through which we found the better approach for removal of voids
Decay Property for Solutions to Plate Type Equations with Variable CoefficientsEditor IJCATR
In this paper we consider the initial value problem for a plate type equation with variable coefficients and memory in
1 n R n ), which is of regularity-loss property. By using spectrally resolution, we study the pointwise estimates in the spectral
space of the fundamental solution to the corresponding linear problem. Appealing to this pointwise estimates, we obtain the global
existence and the decay estimates of solutions to the semilinear problem by employing the fixed point theorem
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OPTICAL SWITCHING CONTROLLER USING FPGA AS A CONTROLLER FOR OCDMA ENCODER SYSTEM
1. International Journal of Science and Engineering Applications
Volume 3 Issue 2, 2014, ISSN-2319-7560 (Online)
www.ijsea.com 6
OPTICAL SWITCHING CONTROLLER USING FPGA AS A
CONTROLLER FOR OCDMA ENCODER SYSTEM
Jaafar, A.
Faculty of Electronic and Computer
Engineering
Universiti Teknikal Malaysia
Melaka (UTeM)
Hang Tuah Jaya, 76100 Durian
Tunggal,Melaka, Malaysia
Saffie, N.B.
Faculty of Electronic and Computer
Engineering
Universiti Teknikal Malaysia
Melaka (UTeM)
Hang Tuah Jaya, 76100 Durian
Tunggal,Melaka, Malaysia
M.H. Sulaiman
Faculty of Electronic and Computer
Engineering
Universiti Teknikal Malaysia
Melaka (UTeM)
Hang Tuah Jaya, 76100 Durian
Tunggal,Melaka, Malaysia
Abstract: This paper proposed a design of optical switching controller using FPGA for OCDMA encoder system. The encoder is one
of the new technologies that use to transmit the coded data in the optical communication system by using FPGA and optical switches.
It is providing a high security for data transmission due to all data will be transmitting in binary code form. The output signals from
FPGA are coded with a binary code that given to an optical switch before it signal modulate with the carrier and transmit to the
receiver. In this paper, AA and 55 data were used for source 1 and source 2. It is generated sample data and sent packet data to the
FPGA and stored it into RAM. The simulation results have done by using software Verilog Spartan 2 programming to simulate. After
that the output will produces at waveform to display the output. The main function of FPGA controlling unit is producing single pulse
and configuring optical switching system.
Keywords: Field programmable gate array (FPGA), Code Division Multiple Access (CDMA), Optical Code Division Multiple Access
(OCDMA), Linear Feedback Shift Register (LFSR), pseudo-noise (PN), Verilog
1. INTRODUCTION
Interest in OCDMA has been steadily growing during recent
decades. That trend is accelerating due to fiber penetration in
the first mile and the establishment of PON technology as a
pragmatic solution for residential access. OCDMA is one
promising technique for next-generation broadband access
network with the following advantages: asynchronous access
capability, accurate time of arrival measurements, and
flexibility of user allocation, ability to support variable bit
rate, busty traffic and security against unauthorized users.
OCDMA is a very attractive multi-access technique that can
be used for local area network (LAN) and the first one mile.
Moreover, the OCDMA method is preferable for multiplexing
in the optical domain because it uses broadband widths in
optical devices for the electrical CDMA method and the
electrical-to-optical (E/O) conversion OCDM is a
multiplexing procedure by which each communication
channel is distinguished by a specific optical code rather than
a wavelength or time-slot[11]. An encoding operation
optically transforms each data bit before transmission. At the
receiver, the reverse decoding operation is required to recover
the original data. OCDMA is the use of OCDM technology to
arbitrate channel access among multiple network nodes in a
distributed fashion. There are many different kinds of
OCDMA encoder/decoders use optical delay lines or optical
switches with optical orthogonal code (OOC) for the time
domain fiber Bragg grating (FBG) or AWGs and OOCs for
the optical frequency domain, and FBGs or AWGs for optical
wavelength-hopping / time spreading (TS)[4]. AWG-based
encoder/decoder has the unique capability of simultaneously
processing multiple time-spreading optical codes (OCs) with
single device, which makes it a potential cost-effective device
to be used in the central office of OCDMA network to reduce
the number of encoder/decoders. The AWG-based
encoder/decoder also has very high power contrast ratio
(PCR) (15~20 dB) between auto- and cross-correlation
signals, which means the interference value could be
significantly reduced (up to 20 dB) with the short OC [1-3].
Code-division multiple-access (CDMA) communication
system allows multiple users to access the network
simultaneously using unique codes.[9-10] Optical CDMA has
the advantage of using optical processing to perform certain
network applications, like addressing and routing without
resorting to complicated multiplexers or demultiplexers. The
asynchronous data transmission can simplify network
management and control. OCDMA is an attractive candidate
for LAN application. Normally, OCDMA can provide a
secure network connection providing dynamic encoding.
OCDMA (Optical CDMA) communication systems do not
require any time or frequency management. It can operate
asynchronously without centralized control and it does not
suffer from packet collisions. As a result, OCDMA systems
have lower latencies than TDMA or In a OCDMA system
each bit is divided up into N time periods, called chips. By
sending short optical pulse during some chip intervals, but no
others, an optical signature sequence or codeword can be
created. Each user on the OCDMA system has a unique
signature sequence. The encoder of the each transmitter
represents each 1bit by sending signature sequence, however a
binary o bit is not encoded and is represented using all-zero
sequence. Since each bit is represented by a pattern of lit and
unlit chips, the bandwidth of the data stream is increased. The
OCDMA is encoded data is then send to an 'N x N' known as
star coupler (in local area network) or '1xN' coupler (in an
access network) and broadcast to all nodes. The crosstalk
between different users sharing the common fiber channel,
known as MAI (Multiple Access Interface) is usually the
dominant source of bit errors in an O-CDMA system. The
main difference of OCDMA systems from wireless CDMA is
the code structure.
2. International Journal of Science and Engineering Applications
Volume 3 Issue 2, 2014, ISSN-2319-7560 (Online)
www.ijsea.com 7
Optical systems are mainly intensity modulated and hence the
chips in the OCDMA system are alternating '1' s and '0' s
instead of '-1' s and '+1' s. In OCDMA the overlap of optical
pulses results in the addition of optical power. Optimum
CDMA codes have been found assuming bipolar signals
which can take on positive and negative values, though optical
signal can also be processed coherently to provide bipolar
signals. Recently practical optical fiber systems use direct
detection and can therefore process only unipolar signals
consisting of "1" s and "0" s. CDMA codes consisting entirely
of '1' s and '0' s are referred to as optical codes and several
variants have been recently proposed in many literature. An
important class of CDMA optical codes is so called set of
OOCs (Orthogonal Optical Codes)[5]. OOC is a family of
(0,1) sequences with good auto and cross correlation
properties. The (1,0) sequences of OOC are called its code
words. In other words, the cross -correlation of two distinct
CDMA codes must take a value as low as possible.
Field Programmable Gate Arrays (FPGAs) are programmable
semiconductor devices that are based around a matrix of
Configurable Logic Blocks (CLBs) connected through
programmable interconnects. Verilog HDL is one of the two
most common Hardware Description Language (HDL) used
by integrated circuit (IC) designers. The other one is
VDHL[6]. HDL’s allows the design to be simulated earlier in
the design cycle in order to correct errors or experiment with
different architectures. Design describes in HDL are
technology independent, easy to design and simulate and are
usually more readable than schematics normally for the large
circuits. Verilog can be used to describe designs at four levels
of abstraction which is algorithms level (much like c code
with if, case and loop statements). Register transfer level
(RTL uses registers connected by Boolean equations). Gate
level (interconnected AND, NOR etc). switch level (the
switches are MOS transistors inside gates). The language also
defines construct that can used to simulate the input and
output. Mostly, Verilog is used as an input for synthesis
programs and will generate a gate level description and
analyze for the coding. Some Verilog construct are not
synthesizable. The code is written will greatly affect the size
and speed of the synthesize. Normally, the readers want to
synthesize their coding, so non synthesizable construct should
be used only for test benches [12-14].
2. OVERVIEW SYSTEM
Figure 1 shows the operation of Code Division Multiple
Access process. At the transmitter, two data sources generated
digital data sequences which are individually multiplied using
two orthogonal code sequences. Both of data user is identified
by its unique code. The serial data sequences are multiplied
by their corresponding PN sequences. The PN code sequence
can be easily generated using Linear Feedback Shift Register
(LFSR). The orthogonal code sequences are generated by
periodically repeating orthogonal codes are at a rate much
greater than the source data rate. The modulated sequence has
wider frequency spectrum more than the original source
sequence. It is called spread spectrum data sequence. The two
spread spectrum data sequences are finally summed up and
transmitted over a common channel.
Figure 1: Block Diagram of Code Division Multiple Access
2.1 pseudo-noise(PN) Generator Operation
This operation consist 7-bit PN code generator by using three
stages Linear Feedback Shift Register (LFSR). The logic
circuit diagram of three stage LFSR implement in Verilog
coding is shown in figure above. This operation of three stage
of LFSR used D flip flop gate. PN generators are separated by
two parts, which entities were implemented, one of each for
two sources. The 3-bit initialize (seed) was set within the
Verilog coding itself for each entity. The PN generator for
source 1 is initialized with (S2 S1 S0) = 110. This input are
generates PN code 1100101. For PN generator for source 2 is
initialized with (S2 S1 S0) = 111. This input are generates PN
code 1110010. The operation of PN generator by using three
stages LFSR shows at figure 2 below. The PN generator
components generate the respective PN sequences for two
sources. To ensure that seven chips in the PN sequence align
exactly with one bit of serial data, the PN sequence is
generated at the master clock rate example master clock rate is
assumed to be 7x. The serial data sequence is generated at one
seven rate of master clock. This operation also used XOR
gate.
Figure 2: Three stage of LFSR
2.2 Linear Feedback Shift Register (LFSR)
The PN generator for spread spectrum is usually implemented
as a circuit consisting of exclusive OR gates and a shift
register, called a Liner Feedback Shift Register (LFSR)[7-8].
The LFSR is a string of 1-bit storage devices. Each device has
an output line, which indicates the value currently stored, and
an input line. At discrete time instants, known as clock times,
the value in the storage device is replaced by the value
indicated by its input line. The entire LFSR is clocked
simultaneously, causing a 1-bit shift along the entire register.
2.3 Data Source
This component reads in 8-bit data from keyboard interface
and shifts out the data serially. It is composed of two entities
Divide by eight and an 8-bit Parallel In Serial Out (piso.vhd)
This component is driven by clock of one seventh master
3. International Journal of Science and Engineering Applications
Volume 3 Issue 2, 2014, ISSN-2319-7560 (Online)
www.ijsea.com 8
clock rate and the output bit changes every 7th master clock
cycle. The serial output is synchronized with PN sequence
such that one data bit period equals seven PN code chips.
2.4 Channel
Channel is the medium through which the signals are
transmitted by using fiber optic cable [7]. A communication
channel can be generally characterized as liner filters and
signals transmitted over the channel suffer distortion due to
channel response and noise. In CDMA, since all user channels
operate simultaneously in the same RF band, the interference
due to the multiple users in same RF channel become more
important factor and it plays vital role in deciding the
performance of the communication system. A mobile channel
includes effects of multipath fading and noise. In the
simulation however, only Additive White Gaussian Noise
(AWGN) channel has been used, which is the simplest
channel models, from analysis point of view. A built in
command awgn() was used to model AWGN channel.
In the simulation communication link has been modeled as a
forward channel where each user data is uniquely identified
and spread using Walsh codes. As mentioned earlier, the
perfect orthogonality of Walsh codes significantly reduces the
probability of error at receiver. In order to simulate bit errors
due to multipath effect, intercellular interferers, random non
orthogonal data were added onto the AWGN channel. These
interfering signals are not orthogonal with the Walsh codes
used for the channels in the concerned cell and thus causes
substantial amount of error. However in order to simulate
error due to the multipath interferences from the users
operating in the same cell or the interferences coming from
users in other cells, random data was added in the channel that
may not be exactly orthogonal to the Walsh codes. At PN
generator operation use three stages Linear Feedback Shift
Register (LFSR). Whereby use three gate XOR to shift the
binary code.
3. EXPERIMENTAL RESULTS
At the PN Generator process, we need to use the three stages
LFSR to generate the output data. Input 110 seed to PN
Generator and will shift using three stages of LFSR used XOR
gate. The output after process shows in table 1 below.
Input 110 = Output 1100101
Table 1. PN generator for input 110
Figure 3: Simulation result for PN generator 110
At the PN Generator process, we need to use the three stages
LFSR to generate the output data. Input 111 seed to PN
Generator and will shift using three stages of LFSR used XOR
gate. The output after process shows in table 2 below.
Input 111 = Output 1110010
Table 2. PN generator for input 111
Clk Q2 Q1 Q0 Output Sequence
1 1 1 1 1
2 0 1 1 1
3 0 0 1 1
4 1 0 0 0
5 0 1 0 0
6 1 0 1 1
7 1 1 0 0
8 1 1 1 1
9 0 1 1 1
10 1 0 1 1
11 1 1 0 0
12 1 1 1 1
Figure 4: Simulation result for coding 111
Clk Q2 Q1 Q0 Output Sequence
1 0 1 1 1
2 0 0 1 1
3 1 0 0 0
4 0 1 0 0
5 1 0 1 1
6 1 1 0 0
7 1 1 1 1
8 0 1 1 1
9 0 0 1 1
10 1 0 0 0
11 0 1 0 0
12 1 0 1 1
4. International Journal of Science and Engineering Applications
Volume 3 Issue 2, 2014, ISSN-2319-7560 (Online)
www.ijsea.com 9
The final output for transmitted data encoder can prove from
calculation.
Input from data 1 was set as AA for encoder 0
Encoder 0 = AA + PN code 110
= 10101010 + 1100101
= 1OF [Eqn 1]
Input from data 2 was set as 55 for encoder 1
Encoder 1 = 55 + PN code 111
= 1010101 + 1110010
= C7 [Eqn 2]
Encoder final = Encoder 0 + Encoder 1
= 10F + C7
= 1D6 [Eqn 3]
Figure 5: Simulation result for final encoder (Transmit)
Figure 5 above shows the simulation result for final encoder
(transmitted) data using FPGA as a controller. The simulation
result has shown at figure above. After running simulation
complete, the result for encoder 0 is 1OF and for encoder 1 is
C7. For final encoder the data transmit is 1D6. The output is 8
bit and show in hex code. The value of 1 is carry flag.
4. CONCLUSION
This paper was carried out two major objectives of
implementing a CDMA system at simulating a CDMA
communication system in Verilog. The first objective was
successfully developed and for the second objective was
successfully accomplished after extensive designing, coding
and testing. A two users CDMA system was implemented in
Verilog and synthesized onto an FPGA board. The operation
of the system was successfully verified. The various PN
Generator topologies were studied and they were synthesized
using Xilinx ISE software. Device Utilization and No of
Logic Blocks of each topology were noted down and
compared with each other. The simulations have done by
using Verilog code.
5. ACKNOWLEDGMENTS
This research is funded by the grant from Faculty of
Electronic and Computer Engineering, Universiti Teknikal
Malaysia Melaka (UTeM) with project number of
PJP/2013/FKEKK(47B)/S01274.
6. REFERENCES
[1] Harold P.E. Stern, Samy A. Mahmoud, “Theory of Code
Division Multiplexing, Communication Systems:
Analysis and Design”, Prentice Hall PTR.
[2] Y. Wang, et al., "Design and experiment of an all-optical
label using FBG-based encoder/decoders," 2009, pp.
727811-1.
[3] M. S. Ab-Rahman, et al., "Development of Low-cost
OCDMA Encoder based on Arrayed Waveguide
Gratings (AWGs) and Optical Switches," World
Academy of Science, Engineering and Technology, vol.
46, 2008.
[4] Shah, “Code Division Multiple Access : A Tutorial”, p6-
10,Wireless Communication, Rowan University,1999.
[5] C. Zhang, et al., "Experimental demonstration of tunable
multiple optical orthogonal codes sequences-based
optical label for optical packets switching," Optics
Communications, vol. 283, pp. 932-938, 2010.
[6] B. Zeidman and Z. Consulting, Introduction to verilog:
IEEE Press, 2000.
[7] K. Skahill, “VHDL for Programmable Logic”, Addison-
Wesley,1999.
[8] A. Dhital, "CDMA System: Simulation and
Implementation," 2006.
[9] S. Prakash, et al., "Compact field programmable gate
array (FPGA) controller for aircraft/aerospace
structures," 2008.
[10] M. Akiyama, et al., "High-performance pulsed-power
generator controlled by FPGA," Plasma Science, IEEE
Transactions on, vol. 38, pp. 2588-2592, 2010.
[11] M. Zainudin, H. Radi, and S. Abdullah, “Face
Recognition using Principle Component Analysis (PCA)
and Linear Discriminant Analysis (LDA),” ijens.org, no.
05, 2012.
[12] A. Jaafar, N. Arasid, N. Hashim, A. Latiff, and H. Rafis,
“Three Bit Subtraction Circuit via Field Programmable
Gate Array,” ijaret.org, vol. 1, no. Viii, pp. 1–13, 2013.
[13] Jaafar, A., Hamidon A.H., A.A. Latiff, Hazli Rafis,
H.H.M. Yusof, W.H.M. Saad, “Modelling of swarm
communication,” Int. J. Adv. Res. Electr. Electron.
Instrum. Eng., vol. 2, no. 8, pp. 3725–3731, 2013
[14] Latiff, A. A., et al. "Comparative Study on Single-And
Double-Pass Configurations for Serial Dual-Stage High
Concentration EDFA.", Int. J. of Research in Eng. and
Tech., vol. 2, no.12,pp. 139-143,2013.