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Design and Performance Analysis of Convolutional Encoder and Viterbi Decoder ...IJERA Editor
In digital communication forward error correction methods have a great practical importance when channel is
noisy. Convolutional error correction code can correct both type of errors random and burst. Convolution
encoding has been used in digital communication systems including deep space communication and wireless
communication. The error correction capability of convolutional code depends on code rate and constraint
length. The low code rate and high constraint length has more error correction capabilities but that also
introduce large overhead. This paper introduces convolutional encoders for various constraint lengths. By
increasing the constraint length the error correction capability can be increased. The performance and error
correction also depends on the selection of generator polynomial. This paper also introduces a good generator
polynomial which has high performance and error correction capabilities.
This paper investigates the use of a new hybrid vector quantizer called Switched Multi stage vector quantization (SWMSVQ) technique using hard and soft decision schemes, for coding of narrow band speech signals. This technique is a hybrid of Switch vector quantization technique and Multi stage vector quantization technique. SWMSVQ quantizes the linear predictive coefficients (LPC) in terms of the line spectral frequencies (LSF). The spectral distortion performance, computational complexity and memory requirements of SWMSVQ using hard and soft decision schemes are compared with Split vector quantization (SVQ) technique, Multi stage vector quantization (MSVQ) technique, Switched Split vector quantization (SSVQ) technique using hard decision scheme, and Multi Switched Split Vector quantization (MSSVQ) technique using hard decision scheme. From results it is proved that SWMSVQ using soft decision scheme is having less spectral distortion, computational complexity and memory requirements when compared to SVQ, MSVQ, SSVQ and SWMSVQ using hard decision scheme, but high when compared to MSSVQ using hard decision scheme. So from results it is proved that SWMSVQ using soft decision scheme is better when compared to SVQ, MSVQ, SSVQ and SWMSVQ using hard decision schemes in terms of spectral distortion, computational complexity and memory requirements but is having greater spectral distortion, computational complexity and memory requirements when compared to MSSVQ using hard decision.
Fixed Point Realization of Iterative LR-Aided Soft MIMO Decoding AlgorithmCSCJournals
Multiple-input multiple-output (MIMO) systems have been widely acclaimed in order to provide high data rates. Recently Lattice Reduction (LR) aided detectors have been proposed to achieve near Maximum Likelihood (ML) performance with low complexity. In this paper, we develop the fixed point design of an iterative soft decision based LR-aided K-best decoder, which reduces the complexity of existing sphere decoder. A simulation based word-length optimization is presented for physical implementation of the K-best decoder. Simulations show that the fixed point result of 16 bit precision can keep bit error rate (BER) degradation within 0.3 dB for 8×8 MIMO systems with different modulation schemes.
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
Optimization of Cmos 0.18 µM Low Noise Amplifier Using Nsga-Ii for UWB Applic...VLSICS Design
A design and optimization of 3-5 GHz single ended Radio Frequency (RF) Low Noise Amplifier (LNA) for
ultra-wide-band (UWB) applications using standard UMC 0.18 μm CMOS technology is reported.
Designing of RF circuit components is a challenging job, since even after performing lengthy calculations
and finding parameter values it is less guarantee that the design performs as expected. In view of this the
optimization tool; Elitist Non-Dominated Sorting Genetic Algorithm (NSGA-II); has been employed to get
the optimized starting values of components in the proposed LNA design. The obtained NSGA-II
parameters were simulated using Cadence Spectre- RF simulator. The designed Low Noise Amplifier
achieves a power gain of 22 dB and a minimum Noise Figure of 3 dB is achieved. It dissipates 12.5 mW of
power out of 1.8 V supply.
Design and Performance Analysis of Convolutional Encoder and Viterbi Decoder ...IJERA Editor
In digital communication forward error correction methods have a great practical importance when channel is
noisy. Convolutional error correction code can correct both type of errors random and burst. Convolution
encoding has been used in digital communication systems including deep space communication and wireless
communication. The error correction capability of convolutional code depends on code rate and constraint
length. The low code rate and high constraint length has more error correction capabilities but that also
introduce large overhead. This paper introduces convolutional encoders for various constraint lengths. By
increasing the constraint length the error correction capability can be increased. The performance and error
correction also depends on the selection of generator polynomial. This paper also introduces a good generator
polynomial which has high performance and error correction capabilities.
This paper investigates the use of a new hybrid vector quantizer called Switched Multi stage vector quantization (SWMSVQ) technique using hard and soft decision schemes, for coding of narrow band speech signals. This technique is a hybrid of Switch vector quantization technique and Multi stage vector quantization technique. SWMSVQ quantizes the linear predictive coefficients (LPC) in terms of the line spectral frequencies (LSF). The spectral distortion performance, computational complexity and memory requirements of SWMSVQ using hard and soft decision schemes are compared with Split vector quantization (SVQ) technique, Multi stage vector quantization (MSVQ) technique, Switched Split vector quantization (SSVQ) technique using hard decision scheme, and Multi Switched Split Vector quantization (MSSVQ) technique using hard decision scheme. From results it is proved that SWMSVQ using soft decision scheme is having less spectral distortion, computational complexity and memory requirements when compared to SVQ, MSVQ, SSVQ and SWMSVQ using hard decision scheme, but high when compared to MSSVQ using hard decision scheme. So from results it is proved that SWMSVQ using soft decision scheme is better when compared to SVQ, MSVQ, SSVQ and SWMSVQ using hard decision schemes in terms of spectral distortion, computational complexity and memory requirements but is having greater spectral distortion, computational complexity and memory requirements when compared to MSSVQ using hard decision.
Fixed Point Realization of Iterative LR-Aided Soft MIMO Decoding AlgorithmCSCJournals
Multiple-input multiple-output (MIMO) systems have been widely acclaimed in order to provide high data rates. Recently Lattice Reduction (LR) aided detectors have been proposed to achieve near Maximum Likelihood (ML) performance with low complexity. In this paper, we develop the fixed point design of an iterative soft decision based LR-aided K-best decoder, which reduces the complexity of existing sphere decoder. A simulation based word-length optimization is presented for physical implementation of the K-best decoder. Simulations show that the fixed point result of 16 bit precision can keep bit error rate (BER) degradation within 0.3 dB for 8×8 MIMO systems with different modulation schemes.
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
Optimization of Cmos 0.18 µM Low Noise Amplifier Using Nsga-Ii for UWB Applic...VLSICS Design
A design and optimization of 3-5 GHz single ended Radio Frequency (RF) Low Noise Amplifier (LNA) for
ultra-wide-band (UWB) applications using standard UMC 0.18 μm CMOS technology is reported.
Designing of RF circuit components is a challenging job, since even after performing lengthy calculations
and finding parameter values it is less guarantee that the design performs as expected. In view of this the
optimization tool; Elitist Non-Dominated Sorting Genetic Algorithm (NSGA-II); has been employed to get
the optimized starting values of components in the proposed LNA design. The obtained NSGA-II
parameters were simulated using Cadence Spectre- RF simulator. The designed Low Noise Amplifier
achieves a power gain of 22 dB and a minimum Noise Figure of 3 dB is achieved. It dissipates 12.5 mW of
power out of 1.8 V supply.
Low complexity design of non binary ldpc decoder using extended min-sum algor...eSAT Journals
Abstract
Low Density Parity Check (LDPC) codes, is a linear block code having the decoding performance closer to Shannon’s limit. Nonbinary
LDPC is the class of binary LDPC, which works on the higher order Galois field. The decoding performance of non-binary
(NB) LDPC is better than binary LDPC for moderate code lengths. The increased computation with the increased order of field is
the major challenge in hardware realization of NB-LDPC. The extension of conventional sum-product algorithm, known as
extended Min-Sum (EMS) algorithm, with reduced computational complexity is used in this paper. However, a tradeoff exists
between computational complexity and decoding performance.
This paper aims at reducing the computational complexity by focusing on the Parity Check Matrix (PCM) modifications. The
bottleneck of the design is large memory requirement and more computation intensive. The modification in the EMS algorithm
can be incorporated to design low complexity hardware architecture of NB-LDPC decoder.
Keywords—Non-binary; LDPC; EMS algorithm; PCM
Hamming net based Low Complexity Successive Cancellation Polar DecoderRSIS International
This paper aims to implement hybrid based Polar
encoder using the knowledge of mutual information and channel
capacity. Further a Hamming weight successive cancellation
decoder is simulated with QPSK modulation technique in
presence of additive white gaussian noise. The experimentation
performed with the effect of channel polarization has shown that
for 256- bit data stream, 30% channels has zero bit and 49%
channels are with a one bit capacity. The decoding complexity is
reduced to almost half as compared to conventional successive
cancellation decoding algorithm. However, the required SNR of
7 dB is achieved at the targeted BER of 10 -4. The penalty paid is
in terms of training time required at the decoding end.
Error control coding using bose chaudhuri hocquenghem bch codesIAEME Publication
Information and coding theory has applications in telecommunication, where error detection
and correction techniques enable reliable delivery of data over unreliable communication channels.
Many communication channels are subject to noise. BCH technique is one of the most reliable error
control techniques and the most important advantage of BCH technique is both detection and
correction can be performed. The technique aims at detecting and correcting of two bit errors in a
code-word of length 15 bits. A seven bit message was specifically chosen so that ASCII characters
can be easily transmitted.
Design and Implementation of Variable Radius Sphere Decoding Algorithmcsandit
Sphere Decoding (SD) algorithm is an implement deco
ding algorithm based on Zero Forcing
(ZF) algorithm in the real number field. The classi
cal SD algorithm is famous for its
outstanding Bit Error Rate (BER) performance and de
coding strategy. The algorithm gets its
maximum likelihood solution by recursive shrinking
the searching radius gradually. However, it
is too complicated to use the method of shrinking t
he searching radius in ground
communication system. This paper proposed a Variabl
e Radius Sphere Decoding (VR-SD)
algorithm based on ZF algorithm in order to simplif
y the complex searching steps. We prove the
advantages of VR-SD algorithm by analyzing from the
derivation of mathematical formulas and
the simulation of the BER performance between SD an
d VR-SD algorithm.
Iterative Soft Decision Based Complex K-best MIMO DecoderCSCJournals
This paper presents an iterative soft decision based complex multiple input multiple output (MIMO) decoding algorithm, which reduces the complexity of Maximum Likelihood (ML) detector. We develop a novel iterative complex K-best decoder exploiting the techniques of lattice reduction for 8×8 MIMO. Besides list size, a new adjustable variable has been introduced in order to control the on-demand child expansion. Following this method, we obtain 6.9 to 8.0 dB improvement over real domain K-best decoder and 1.4 to 2.5 dB better performance compared to iterative conventional complex decoder for 4th iteration and 64-QAM modulation scheme. We also demonstrate the significance of new parameter on bit error rate. The proposed decoder not only increases the performance, but also reduces the computational complexity to a certain level.
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
Mimo radar detection in compound gaussian clutter using orthogonal discrete f...ijma
This paper proposes orthogonal Discrete Frequency Coding Space Time Waveforms (DFCSTW) for
Multiple Input and Multiple Output (MIMO) radar detection in compound Gaussian clutter. The proposed
orthogonal waveforms are designed considering the position and angle of the transmitting antenna when
viewed from origin. These orthogonally optimized show good resolution in spikier clutter with Generalized
Likelihood Ratio Test (GLRT) detector. The simulation results show that this waveform provides better
detection performance in spikier Clutter.
SpecialPrint - Presentazione per convegno "Nobilitare uno stampato"Cultura Digitale
Presentazione di Claudio Parietti - SpecialPrint - in occasione del convegno "Nobilitare uno stampato? Si può, si deve!" che si è svolto a Bergamo il 24 maggio 2007
JAMBO BUKOBA e. V. *** AIDS Aufklaerung, Maedchen staerken und Bildung verbes...Jambo Bukoba e. V.
Wir machen Kinder durch Sport stark in Tansania!
Jambo Bukoba e. V. nutzt in Tansania Sportunterricht um über HIV/AIDS aufzuklaeren, Chancengleichheit für Maedchen zu foerdern und die Bildungssituation zu verbessern. Dazu bilden wir Tansanische SportlehrerInnen zu Mittler und Vorbilder aus.
Low complexity design of non binary ldpc decoder using extended min-sum algor...eSAT Journals
Abstract
Low Density Parity Check (LDPC) codes, is a linear block code having the decoding performance closer to Shannon’s limit. Nonbinary
LDPC is the class of binary LDPC, which works on the higher order Galois field. The decoding performance of non-binary
(NB) LDPC is better than binary LDPC for moderate code lengths. The increased computation with the increased order of field is
the major challenge in hardware realization of NB-LDPC. The extension of conventional sum-product algorithm, known as
extended Min-Sum (EMS) algorithm, with reduced computational complexity is used in this paper. However, a tradeoff exists
between computational complexity and decoding performance.
This paper aims at reducing the computational complexity by focusing on the Parity Check Matrix (PCM) modifications. The
bottleneck of the design is large memory requirement and more computation intensive. The modification in the EMS algorithm
can be incorporated to design low complexity hardware architecture of NB-LDPC decoder.
Keywords—Non-binary; LDPC; EMS algorithm; PCM
Hamming net based Low Complexity Successive Cancellation Polar DecoderRSIS International
This paper aims to implement hybrid based Polar
encoder using the knowledge of mutual information and channel
capacity. Further a Hamming weight successive cancellation
decoder is simulated with QPSK modulation technique in
presence of additive white gaussian noise. The experimentation
performed with the effect of channel polarization has shown that
for 256- bit data stream, 30% channels has zero bit and 49%
channels are with a one bit capacity. The decoding complexity is
reduced to almost half as compared to conventional successive
cancellation decoding algorithm. However, the required SNR of
7 dB is achieved at the targeted BER of 10 -4. The penalty paid is
in terms of training time required at the decoding end.
Error control coding using bose chaudhuri hocquenghem bch codesIAEME Publication
Information and coding theory has applications in telecommunication, where error detection
and correction techniques enable reliable delivery of data over unreliable communication channels.
Many communication channels are subject to noise. BCH technique is one of the most reliable error
control techniques and the most important advantage of BCH technique is both detection and
correction can be performed. The technique aims at detecting and correcting of two bit errors in a
code-word of length 15 bits. A seven bit message was specifically chosen so that ASCII characters
can be easily transmitted.
Design and Implementation of Variable Radius Sphere Decoding Algorithmcsandit
Sphere Decoding (SD) algorithm is an implement deco
ding algorithm based on Zero Forcing
(ZF) algorithm in the real number field. The classi
cal SD algorithm is famous for its
outstanding Bit Error Rate (BER) performance and de
coding strategy. The algorithm gets its
maximum likelihood solution by recursive shrinking
the searching radius gradually. However, it
is too complicated to use the method of shrinking t
he searching radius in ground
communication system. This paper proposed a Variabl
e Radius Sphere Decoding (VR-SD)
algorithm based on ZF algorithm in order to simplif
y the complex searching steps. We prove the
advantages of VR-SD algorithm by analyzing from the
derivation of mathematical formulas and
the simulation of the BER performance between SD an
d VR-SD algorithm.
Iterative Soft Decision Based Complex K-best MIMO DecoderCSCJournals
This paper presents an iterative soft decision based complex multiple input multiple output (MIMO) decoding algorithm, which reduces the complexity of Maximum Likelihood (ML) detector. We develop a novel iterative complex K-best decoder exploiting the techniques of lattice reduction for 8×8 MIMO. Besides list size, a new adjustable variable has been introduced in order to control the on-demand child expansion. Following this method, we obtain 6.9 to 8.0 dB improvement over real domain K-best decoder and 1.4 to 2.5 dB better performance compared to iterative conventional complex decoder for 4th iteration and 64-QAM modulation scheme. We also demonstrate the significance of new parameter on bit error rate. The proposed decoder not only increases the performance, but also reduces the computational complexity to a certain level.
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
Mimo radar detection in compound gaussian clutter using orthogonal discrete f...ijma
This paper proposes orthogonal Discrete Frequency Coding Space Time Waveforms (DFCSTW) for
Multiple Input and Multiple Output (MIMO) radar detection in compound Gaussian clutter. The proposed
orthogonal waveforms are designed considering the position and angle of the transmitting antenna when
viewed from origin. These orthogonally optimized show good resolution in spikier clutter with Generalized
Likelihood Ratio Test (GLRT) detector. The simulation results show that this waveform provides better
detection performance in spikier Clutter.
SpecialPrint - Presentazione per convegno "Nobilitare uno stampato"Cultura Digitale
Presentazione di Claudio Parietti - SpecialPrint - in occasione del convegno "Nobilitare uno stampato? Si può, si deve!" che si è svolto a Bergamo il 24 maggio 2007
JAMBO BUKOBA e. V. *** AIDS Aufklaerung, Maedchen staerken und Bildung verbes...Jambo Bukoba e. V.
Wir machen Kinder durch Sport stark in Tansania!
Jambo Bukoba e. V. nutzt in Tansania Sportunterricht um über HIV/AIDS aufzuklaeren, Chancengleichheit für Maedchen zu foerdern und die Bildungssituation zu verbessern. Dazu bilden wir Tansanische SportlehrerInnen zu Mittler und Vorbilder aus.
On September 11, in Pittsburgh, Future Bike will meet at the intersections of difference to create a vision for bicycling that elevates new voices, engages local communities and reimagines how we create streets that are vibrant public spaces that bring us together.
Organized by the League of American Bicyclists, this half-day event will include dynamic discussions on leadership, messaging, engagement, education, planning, and technology.
Learn more and register at bikeleague.org/futurebike
Climax Media makes business social. We create concept designs and construct exhibition stands to make your business presence competitive, and leave a lasting impression with a well organized presentation. To achieve this, we exploit various avenues, including social media to captivate your audience. Climax Media strives go the extra mile to make events work for you. Our proposal is to create a platform for you that will present your company as professional, stable and trustworthy thus favorable for viable business partnership, customer satisfaction and growth.
Guida al mantenimento e alla pulizia dei divani in pelle. Ditre Italia ha realizzato e distribuito questo utile manuale in italiano, inglese, francese e tedesco.
Cross Spectral Density Analysis for Various Codes Suitable for Spread Spectru...IJMER
International Journal of Modern Engineering Research (IJMER) is Peer reviewed, online Journal. It serves as an international archival forum of scholarly research related to engineering and science education.
International Journal of Modern Engineering Research (IJMER) covers all the fields of engineering and science: Electrical Engineering, Mechanical Engineering, Civil Engineering, Chemical Engineering, Computer Engineering, Agricultural Engineering, Aerospace Engineering, Thermodynamics, Structural Engineering, Control Engineering, Robotics, Mechatronics, Fluid Mechanics, Nanotechnology, Simulators, Web-based Learning, Remote Laboratories, Engineering Design Methods, Education Research, Students' Satisfaction and Motivation, Global Projects, and Assessment…. And many more.
Performance Study of RS (255, 239) and RS (255.233) Used Respectively in DVB-...IJERA Editor
The error correction codes have a wide range of applications in digital communication (satellite, wireless) and digital data storage. This paper presents a comparative study of performance between RS (255, 239) and RS (255.233) used respectively in the Digital Video Broadcasting – Terrestrial (DVB-T) and National Aeronautics and Space Administration (NASA). The performances were evaluated by applying modulation scheme in additive white Gaussian noise (AWGN) channel. Performances of modulation with RS codes are evaluated in bit error rate (BER) and signal energy -to- noise power density ratio (Eb / No). The analysis is studied with the help of MATLAB simulator to analyze a communication link with AWGN Channel, and different modulations.
Improving The Performance of Viterbi Decoder using Window System IJECEIAES
An efficient Viterbi decoder is introduced in this paper; it is called Viterbi decoder with window system. The simulation results, over Gaussian channels, are performed from rate 1/2, 1/3 and 2/3 joined to TCM encoder with memory in order of 2, 3. These results show that the proposed scheme outperforms the classical Viterbi by a gain of 1 dB. On the other hand, we propose a function called RSCPOLY2TRELLIS, for recursive systematic convolutional (RSC) encoder which creates the trellis structure of a recursive systematic convolutional encoder from the matrix “H”. Moreover, we present a comparison between the decoding algorithms of the TCM encoder like Viterbi soft and hard, and the variants of the MAP decoder known as BCJR or forward-backward algorithm which is very performant in decoding TCM, but depends on the size of the code, the memory, and the CPU requirements of the application.
In OFDM-IDMA scheme, intersymbol interference (ISI) is resolved by the OFDM layer and multiple access interference (MAI) is suppressed by the IDMA layer at low cost . However OFDM-IDMA scheme suffers high peakto-average power ratio (PAPR) problem. For removing high PAPR problem a hybrid multiple access scheme SC-FDM-IDMA has been proposed. In this paper, bit error rate (BER) performance comparison of SC-FDM-IDMA scheme, OFDM-IDMA scheme and IDMA scheme have been duly presented. Moreover, the BER performance of various subcarrier mapping methods for SC-FDM-IDMA scheme as well as other results with variation of different parameters have also been demonstrated. Finally simulation result for BER performance improvement has been shown employing BCH code. All the simulation results demonstrate the suitability of SC-FDMIDMA scheme for wireless communication under AWGN channel environment.
In this paper, low linear architectures for analyzing the first two maximum or minimum values are of paramount importance in several uses, including iterative decoders. The min-sum giving out step is to that it produces only two diverse output magnitude values irrespective of the number of incoming bit-to check communication. These new micro-architecture structures would utilize the minimum number of comparators by exploiting the concept of survivors in the search. These would result in reduced number of comparisons and consequently reduced energy use. Multipliers are complex units and play an important role in finding the overall area, speed and power consumption of digital designs. By using the multiplier we can minimize the parameters like latency, complexity and power consumption. The decoding algorithms we propose generalize and unify the decoding schemes originally presented the product codes and those of low-density parity-check codes.
PERFORMANCE EVALUATION OF BER FOR AWGN, AWGN MULTIPATH AND RAYLEIGH FADING CH...IJEEE
The objectives of this paper are to study, analyze and evaluate the performance of BER (Bit Error Rate) in mobile multipath fading propagation channel. The parameters which are considered for the performance evaluation are AWGN, AWGN Multipath, Rayleigh fading channel and Hadamard code generator.
Reduced Energy Min-Max Decoding Algorithm for Ldpc Code with Adder Correction...ijceronline
In this paper, high linear architectures for analysing the first two maximum or minimum values are of paramount importance in several uses, including iterative decoders. We proposed the adder and LDPC. The min-sum processing step that it gives only two different output magnitude values irrespective of the number of incoming bit-to check messages. These new micro-architecture layouts would employ the minimum number of comparators by exploiting the concept of survivors in the search. These would result in reduced number of comparisons and consequently reduced energy use. Multipliers are complex units and play an important role in finding the overall area, speed and power consumption of digital designs. By using the multiplier we can minimize the parameters like latency, complexity and power consumption.
Generation of Orthogonal Minimum Correlation Spreading Code for CDMA Systemidescitation
Code Division Multiple Access (CDMA) is one of the
most promising tools for multiple access in future generation
wireless communication systems. In CDMA system, within
the specific bandwidth a large number of users could be served
by assigning specific code to each user. In this paper, an attempt
has been made to generate a novel orthogonal spreading code
to support a large number of users for CDMA system by
maintaining minimum correlation values between them. The
proposed “Orthogonal Minimum Correlation Spreading
Code” (OMCSC) would be able to provide a large number of
spreading codes by simultaneously reducing the effect of
M ultiple Access Interference (MAI) in CDM A system.
Moreover, the Bit Error Rate (BER) performance of the
proposed code has been compared with different existing codes
in order to establish the supremacy of the proposed code over
the others under multi-user scenario.
International Journal of Engineering Research and Development (IJERD)IJERD Editor
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International Journal of Engineering Research and Development (IJERD)IJERD Editor
journal publishing, how to publish research paper, Call For research paper, international journal, publishing a paper, IJERD, journal of science and technology, how to get a research paper published, publishing a paper, publishing of journal, publishing of research paper, reserach and review articles, IJERD Journal, How to publish your research paper, publish research paper, open access engineering journal, Engineering journal, Mathemetics journal, Physics journal, Chemistry journal, Computer Engineering, Computer Science journal, how to submit your paper, peer reviw journal, indexed journal, reserach and review articles, engineering journal, www.ijerd.com, research journals,
yahoo journals, bing journals, International Journal of Engineering Research and Development, google journals, hard copy of journal
Performance Analysis of DRA Based OFDM Data Transmission With Respect to Nove...IJERA Editor
In this paper, we have analyzed the performance characteristics of OFDM data transmission with regard to a new high speed RS decoding algorithm. The various characteristics identified are mainly speed and accuracy of the transmission irrespective of channel behaviour. We consider two cases viz. data transmission without error control and data transmission with error control. Each of these cases are duly analyzed and it is proven that high speed RS decoding algorithms can actually benefit OFDM data transmission for advanced communication systems only if implemented at the hardware (VLSI) level because of significant processing overhead involved in software based implementation even though the algorithm may have lower computational complexity.
LDPC Encoding and Hamming Encoding using MATLAB.
An LDPC code is a linear block code characterised by a very sparse parity-check matrix. This means that the parity check matrix has a very low concentration of 1’s in it, hence the name is “low-density parity-check” code. The sparseness of LDPC codes is what as it can lead to excellent performance in terms of bit error rates.
GF(q) LDPC encoder and decoder FPGA implementation using group shuffled beli...IJECEIAES
This paper presents field programmable gate array (FPGA) exercises of the GF(q) low-density parity-check (LDPC) encoder and interpreter utilizing the group shuffled belief propagation (GSBP) algorithm are presented in this study. For small blocks, non-dual LDPC codes have been shown to have a greater error correction rate than dual codes. The reduction behavior of non-binary LDPC codes over GF (16) (also known as GF(q)-LDPC codes) over the additive white Gaussian noise (AWGN) channel has been demonstrated to be close to the Shannon limit and employs a short block length (N=600 bits). At the same time, it also provides a non-binary LDPC (NB-LDPC) code set program. Furthermore, the simplified bubble check treasure event count is implemented through the use of first in first out (FIFO), which is based on an elegant design. The structure of the interpreter and the creation of the residential area he built were planned in very high speed integrated circuit (VHSIC) hardware description language (VHDL) and simulated in MODELSIM 6.5. The combined output of the Cyclone II FPGA is combined with the simulation output.
PERFORMANCE ANALYSIS OF QOS PARAMETERS LIKE PSNR, MAE & RMSE USED IN IMAGE TR...Journal For Research
Wireless designers constantly seek to improve the spectrum efficiency/capacity, coverage of wireless networks and link reliability. In this direction, Space-time wireless technology that uses multiple antennas along with appropriate signaling and receiver techniques that offers a powerful tool for improving the wireless performance is used in this thesis work. A special version of STBC called ‘Alamouti code’ is used. PSK modulation scheme is used for modulation of data. In this thesis work, the Space-Time Block Codes (STBC) is used in WLAN wireless network that uses multiple numbers of antennas at both transmitter and receiver. The STBC which includes the Alamouti Scheme for 2 transmit antenna and a different number of receiving antenna has been studied, simulated and analyzed. The simulation has been done in MATLAB. Throughput and several parameter performance has been analyzed using the MATLAB.A sample image is transmitted to compare the performance of various parameters like RMSE, PSNR, MAE etc. All the parameters are plotted against SNR (in dB) values ranging from -18 to 30. Various observations being made for the improvement in various parameters with increasing SNR and/or with changing diversity scheme. AWGN channel is used here for communication of sampled image data.
Analysis and Simulation of Pseudo Ranging Noise codes for Geo-Stationary Sate...IDES Editor
The Geo-Stationary Navigation Satellite System
will provides basically two types of services 1) Standard
Positioning Service (SPS) and 2) Restricted Service (RS).
Both of these services are provided at two frequencies of L
and S-Band. The code sequences used in SPS and RS are
Pseudo Ranging Noise (PRN) codes. In SPS downlink, it is
planned to use Gold Codes for navigation data transmission.
The RS navigation down link has signals with pilot component
and data component. The pilot component uses primary code
and secondary code to get final code known as tiered code.
The primary code is truncated Gold code. The secondary
code is PRN sequence code. The data component of RS service
uses truncated PRN sequence code. This paper presents the
performance analysis and simulation results of auto
correlation function (ACF) and Cross correlation function
(CCF) properties for Gold code, Kasami codes and it’s
truncation effect. Apart from ACF and CCF, Doppler
frequency shift on L & S-band carrier frequencies and
Doppler frequency shift on L & S band Codes are carried
out. The simulations of ACF & CCF on codes and Doppler
effects were analyzed using Matlab and System View design
tool and results are compared with Welch bound. The
simulated test results are well within the theoretical limits.
LDPC Encoding is explained in this ppt. for MATLAB code and more information you can visit link given below:
http://www.slideshare.net/bhagwatsinghmahecha/itc-final-report
Performances Concatenated LDPC based STBC-OFDM System and MRC Receivers IJECEIAES
This paper presents the bit error rate performance of the low density parity check (LDPC) with the concatenation of convolutional channel coding based orthogonal frequency-division-multiplexing (OFDM) using space time block coded (STBC). The OFDM wireless communication system incorporates 3/4rated convolutional encoder under various digital modulations (BPSK, QPSK and QAM) over an additative white gaussian noise (AWGN) and fading (Raleigh and Rician) channels. At the receiving section of the simulated system, Maximum Ratio combining (MRC) channel equalization technique has been implemented to extract transmitted symbols without enhancing noise power.
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Performance Analysis of GDFT with Non Linear Phase on Real Time System
1. International Journal of Engineering Inventions
e-ISSN: 2278-7461, p-ISSN: 2319-6491
Volume 2, Issue 8 (May 2013) PP: 60-66
www.ijeijournal.com Page | 60
PerformanceAnalysis of GDFTwith NonLinearPhaseon RealTime
System
Mr. Umesh Sakhare1
, Prof. Lalit Dole2
1, 2
Department of Computer Science & Engineering, G. H. Raisoni College of Engineering, Nagpur,
Maharashtra, India
Abstract: Cellular phone communication (CPC) has been developed throughout the world. During the
development of CPC, Quality of Service (QoS) needs to maintain. To maintain QoS the requirement of CPC is to
be satisfied. For CPC there are two techniques which are dominating with each other GSM and CDMA. This
paper is dealing with CDMA technology and their requirement. CDMA technology uses the spreading code in
order to improve frequency band spectrum. CDMA technology is based on wide-band and to improve the band
spectrum, spreading code is used. Binary sequence like pseudo random sequence (PN-Sequence), m-ary
sequences can be used as spreading code in wireless communication. Spreading codes are used to increase the
spread spectrum and proper utilization of the bandwidth. Spreading code is having better result in wireless
communication. The various spreading codes like M-ary Binary sequences, Gold codes, Walsh codes and
Constant modulus function set (GDFT) used in various applications like Discrete Multi-tone, Orthogonal
Frequency Division Multiple Access (OFDM), and Code Division Multiple Access (CDMA).
This paper deals with simulation of spreading code like Gold, Walsh and Generalized Discrete Fourier
Transform codes on real time system by using MATLAB environment. In this model Gold and Walsh and GDFT
spreading codes are modulated with voice or speech signal. Performance result can be analyzed in terms of Bit-
Error-Rate (BER), Signal-to-Noise ratio (SNR) and Mean Square Value of auto-correlation and Mean Square
Value of Cross-Correlation. The experimental result shows the efficient technique used in CDMA.
Keywords: Generalized Discrete Fourier Transform, Bandwidth, Auto-Correlation function, Cross-Cross
Correlation function, Bit Interference, PN Sequence, CDMA, Gold Codes, Walsh Codes, Discrete Fourier
Transform
I. Introduction
CDMA is one of the techniques of cellular phone communication. CDMA provides better voice quality as
compare to GSM.
1.1 Gold Code
Combining two m-sequences creates Gold codes. These codes are used in asynchronous CDMA
systems. Gold sequences are important class of sequences that allow construction of long sequences with three
valued auto-correlation function ACF’s. Gold sequences are constructed from pairs of preferred m-sequences by
modulo-2 addition of two maximal sequences of same length.
Gold sequences are useful in non-orthogonal CDMA. Gold sequences have only three cross-correlation
peaks, which tend to get less important as the length of the code increases. They also have a single auto-
correlation peak at zero, just like ordinary PN sequences. The use of Gold sequences permits the transmission to
be asynchronous. The receiver can synchronize using the auto-correlation property of gold sequence.
1.2 Gold Theorem
Let G1(x) and G2(x) be a preferred pair of primitive polynomials of degree n whose corresponding shift
register generate m-sequences of period 2n
-1 and correlation function has a magnitude less than or equal to
2(n+1) / 2
+ 1 for n odd, or
2(n+2) / 2
+1 for n even and n≠0 mod
Then the shift registers corresponding to the product polynomial G1(X).G2(X) will generate 2n
+1 different
sequence, with each sequence having a period of 2n
-1 and the correlation sequence are defined in the next
section.
1.3 Correlation Properties of Gold Code Sequence
Consider a period of 2n
-1 =127 is considered. To generate such sequence for n=7, it needs a preferred
pair of PN sequences that satisfy as 2(n+1)
/2+1 =24+1=17. This requirement is satisfied by the PN sequences with
feedback taps (7, 4) and (7, 6, 5, 4). The gold sequence generator is shown in figure-2.A According to Gold’s
2. Performance Analysis of GDFT with Non Linear Phase on Real Time System
www.ijeijournal.com Page | 61
theorem there are a total of 2n
+1=27
+1=129 sequences that satisfy 2(n+1)
/2+1. In particular, the magnitude of the
cross correlation is less than or equal to 17.
1.4 Walsh Code
Walsh codes are created out of Hadamard is the matrix type from which Walsh created this codes.
Walsh codes have just one outstanding quality. In a family of Walsh codes all codes are orthogonal to each other
and are used to create channelization within the 1.25 MHz band. Walsh codes of length 2n
can be defined and
generated as different rows of a 2n
×2n
Hadamard matrix. The following recursive equation can be used to
generate higher order Hadamard matrices from lower once.
For example starting with a=1×1 matrix H1=[0], one can define Walsh codes of length 4 as follows
H1= [ 0 ]
Where W0 W1 are defined as different rows of a 4×4 Hadamard matrix and represented in binary or
bipolar format. These rows are mutually orthogonal to each other.
1.5 Generalized Discrete Fourier Transform (GDFT)
An Nth
root of unity is a complex number z satisfying the polynomial equation.
zN
-1 = 0 N Є { 1, 2, 3 } ( 1)
All primitive Nth roots of unity satisfy the unique summation property of a geometric series expressed as
follows:
Now define a periodic, constant modulus complex sequence as the rth power of the first primitive Nth
roots of unity
Where n = 0,1,2,3,…N-1 and r = 0,1,2,..N-1 The complex sequence III over a finite discrete time interval in a
geometric series is expressed as follows [1][2]
Algorithm:
Step 1: Find N × N DFT
Step 2: Find G1 and G2 are constant modulus diagonal matrices and written as follows
and
3. Performance Analysis of GDFT with Non Linear Phase on Real Time System
www.ijeijournal.com Page | 62
Step 3: Calculate GDFT
Step 4: Find maximum value of out of phase Auto Correlation ( dam), maximum value of out of phaes Cross
Correlation (dcm), Mean Square Value of Auto Correlation Rac, Mean Square Value of Cross Correlation Rcc
and Merit Factor.
Step 5: Simulate using AWGN.
Step 6: Plot BER and SNR
II. Related Work
T.M. Nazmul Huda, Syed Islam analyzed correlation of Gold and Walsh code on the basis of
generation of code of little particular lengths. Here, random noise to the generated codes has been added and it
tried to find out how Gold and Walsh code act on application of random noise. Correlation is tested for the
codes, which shows better result. Here the code is generated on the basis of only a pair of m-sequences of length
five. Random noise is based on uniform distribution [1].
Vaishali Patil, Jaikaran Singh, Mukesh Tiwari simulated mathematical model of Gold Codes, Walsh
Codes and GDFT and analyzed the result in terms of BER and SNR. It has been observed that GDFT provides
better and efficient correlation function which can be exploited in optimum way of asynchronous CDMA
communication system rather than Gold and Walsh codes [2].
Ali Akanshu, Handan Agirman-Tosun proposed a mathematical model of Generalized Discrete Fourier
Transform (GDFT) to generate spreading code. GDFT can be derived by the definition of Discrete Fourier
Transform. GDFT provides a unified theoretical framework where popular constant modulus orthogonal
function set including DFT provides foundation to exploits the phase space to improve the correlation property
of constant modulus orthogonal set. It is found that GDFT improved correlation over popular DFT, Gold and
Walsh as well as Oppermann families, is leading to superior communication performance for the scenario
considered in this paper [3][5].
III. Proposed System
The proposed work is the MATLAB simulation of Gold and Walsh on a real time system. Real time system
model architecture designed as below
Fig. 1 Real Time System Model at Modulation Fig. 2 Real Time System Model at De-Modulation
In this proposed work, system work on input voice signal V(i) recorded by different person. This input
signal is modulated by Gold and Walsh code sequence. Same input signal is recovered back. Finally correlate
the original signal and recovered signal. The performance of Real Time System can be observed on BER, SNR
and Mean Square value. Real Time System approach works on various spreading coding techniques and
mentioned in below section.
3.1 Real Time System with Gold Code (RTSGC)
RTSGC uses Gold code as spreading code, here input voice signal V(i) is recorded with sampling
frequency (Fs) of 8000 Hz, and Number of samples (ns) is equal to Fs. Gain of input signal GN = 2 * ns. Graph
shows the input signal in time as well as frequency domain.
Input
(Voice)
Modul-
ation
Spread-
ing
Noise
(AWGN
)
OUTPUT
V(i).X(i)+
s(n)
OUTPU
T
V(i).X(i)
+ s(n)
DeModu
-lation
Original
Signal
V(i)
FilterDispreading /
Correlation
4. Performance Analysis of GDFT with Non Linear Phase on Real Time System
www.ijeijournal.com Page | 63
Fig 3. Input Signal in Time Fig 4. Input & Frequency Domain
A channel noise AWGN is added to input signal. Output after adding AWGN noise is y a ( i ) = v a ( i ) +AWGN.
Fig. Shows the output signal y a ( i ).
Fig. 5 AWGN noise with input signal Fig. 6 Gold Code Sample of 31 code length.
Here AWGN noise is varies from 0-40 DB.
Gold code is generated which is of 31 bits code length. Gold code is explained in above section. For
example the Gold Code G(x) is 1 -1 -1 -1 1 1 1 1 -1 -1 -1 -1 -1 1 1 1 1 -1 -1 1 1 1 -1 -1 -1 -1 1 1 -1 1 -1. Gold is
further used as spreading code, which will also acts as modulating code. Now, modulating signal is y(x) =
[v( i ) × G ( x )] + AWGN . Fig. shows the modulating signal in Time Vs Amplitude (Time Domain).
Now, Challenge is to recover the original signal as it is,
for that process of demodulation takes place. In the this
process, Gold code G( x ) of code length 31 bits has been
recovered by using correlation function. AWGN noise
added by the channel is removed by using filter. Filter
removes all the noise samples added to the system. Result
of this system is discussed in next section. Original signal
is recovered and compared with input signal and both
merely same signal. It is observed that in Real Time
System, some signal has been lost and not getting 100%
pure input signal, due to channel medium. Loss in signal
(SNR and BER) is represents in next section of
Experimental Results.
Now, Challenge is to recover the original signal as it is, for that process of demodulation takes place. In the this
process, Gold code G( x ) of code length 31 bits has been recovered by using correlation function. AWGN noise
added by the channel is removed by using filter. Filter removes all the noise samples added to the system. Result
of this system is discussed in next section. Original signal is recovered and compared with input signal and both
merely same signal. It is observed that in Real Time System, some signal has been lost and not getting 100%
pure input signal, due to channel medium. Loss in signal (SNR and BER) is represents in next section of
Experimental Results.
Fig. 7 Modulating Signal in Time Domain
5. Performance Analysis of GDFT with Non Linear Phase on Real Time System
www.ijeijournal.com Page | 64
Fig. 8 The process of De-Modulation
3.2 Real Time System with Walsh Code (RTSWC)
In the process of modulation, RTSWC uses Walsh code as spreading code, here again, input voice
signal V(i) is recorded with sampling frequency (Fs) of 8000 Hz, and Number of samples (ns) is equal to Fs.
Gain of input signal GN=2*ns. Again channel noise AWGN is added to input signal. Output after adding
AWGN noise is y b ( i ) = v b ( i ) + AWGN. Fig. Shows the output signal y b ( i ). Here AWGN noise is
varies from 0-40 DB.
Walsh code is generated which is of 31 bits code length. Every bit of Walsh code is orthogonal to each
other. Walsh code is explained in above section. The output signal after process of modulation is y(x) = v ( i ) +
AWGN × W ( x ) as shown in fig.
Fig. 9 The process of Modulation Fig. 10 The process of De Modulation
Now, again same challenge is to recover the original signal from modulated signal, for that, process of
demodulation takes place. In the this process, Walsh code W ( x ) of code length 31 bits has been recovered by
using correlation function. AWGN noise added by the channel is removed by using filter. Filter removes all the
noise samples added to the system. Here also original signal is recovered and compared with input signal and
both merely same signal. It is observed that in Real Time System, some sample of signal has been lost due to
noise and not getting 100% pure input signal. Loss in signal (SNR and BER) is discussed in next section of
Experimental Results. Above figure shows graph of Modulated signal, Walsh code signal and Original signal.
6. Performance Analysis of GDFT with Non Linear Phase on Real Time System
www.ijeijournal.com Page | 65
3.3 Real Time System with GDFT Code (RTSGDFT)
Fig. 10 shows er(n) which is the periodic constant modulus sequence and plays an important role in
Generalized Discrete Fourier Transform. It is the complex valued sequence as the rth
power of the first primitive
Nth root of unity. Hence it has zeros on the unit circle in Z- plane as shown in fig. 11
Fig.11 The periodic constant modulus sequences er(n) Fig. 12 Pole/Zero plot for primitive Nth root of unit
GDFT spreading code is used for the process of modulation. The fig. shows the process of modulation
where the AWGN channel noise is added with input signal. Output after modulation process is Y(x) = [V(i) ×
GDFT] AWGN. In DeModulation process spreading codes are to be dispread after transmission, the correlation
function is required for it. Noise is filter out by using wide band filter.
Fig. 13 The process of GDFT Modulation Fig. 14 Process of GDFT demodulation
IV. Result
Performance of Gold code, Walsh, and GDFT code
families and their correlation is analyzed in terms of
Signal to Noise ratio (SNR) and Bit Error Rate. As SNR
is increases the BER is decreases. The figure shows the
analysis of Gold code, Walsh and GDFT on Real time
system. From the figure it is clear that GDFT having
better result. However, due to its lower cross correlation
functi on value it gives the better result in Multipath
fading.
Fig. 15 Performance Comparison of Spreading
Again in order to compare performance of code families several objective performance metrics
codesare used. Table 1. Shows comparative results of Gold, Walsh and GDFT spreading family of their out of
phase Auto correlation (dam), out of phase cross correlation (dcm), Mean Square value of Auto Correlation
(RAC), Mean Square value of cross correlation (RCC).
7. Performance Analysis of GDFT with Non Linear Phase on Real Time System
www.ijeijournal.com Page | 66
Table 1: Performance Comparison of spreading code
V. Conclusion
In this paper we have implemented spreading code Gold, Walsh and GDFT. GDFT Spreading code can
be used in CDMA which is having better result and effective correlation function as compare to Gold, Walsh
and any other M-Ary binary sequences on real time system. The low value of RAC is desired to magnitude
multipath effect of the channel. Maximum Value of Merit Factor is best for CDMA communication. GDFT code
can improves QoS for CDMA. Especially Gold code is used in asynchronous data transmission in CDMA.
References
[1] T. M. Nazmul Huda, Syed Islam “Correlation Analysis of the Gold Codes and Walsh Codes in CDMA Technology”, IEEE, 2009
[2] Vaishali Patil, Jaikaran Singh, Mukesh Tiwari “Simulation of GDFT for CDMA”, MPGI National Muti-Conference 2012.
[3] Ali N. Akanshu, Handan Agirman “Generalized Discrete Fourier Transform”, IEEE Transaction on Signal Processing, vol 58, N0.9,
Septmber 2010.
[4] Hidenobu Fukumasa , Ryuji Kohno, and Hideki Imai “Design of Pseudo Random Noise Sequences with Good Odd and Even
Correlation Properties” IEEE Second International Symposius on Spread Sprectrum tech. and Application, Japan Nov 29 Dec 2, 1992
[5] Richard Haddad Ali Akansu “A new Orthogonal Transform for signal Coding”.
[6] Richard Haddad Ali Akansu “A new Orthogonal Transform for signal Coding”.
[7] Ian Oppermann “Orthogonal Complex Valued Spreading Sequences with a wide Range of Correlation Properties”, IEEE transaction
on communication Vol. 45, N0 11, Nov 1997.
[8] A. K. S. Al- Bayati and S. Prasad “Modified constant modulus algorithm for blind DS/CDMA”, Electronics Lett, 1999.
[9] Ian Oppermann and B.S. Vucetic “Complex Valued Spreading Sequences with a wide Range of Correlation Properties”, IEEE
transaction on communication Vol. 45,pp. 365-375 N0 11, March
[10] Cenk Kose, Keith M. Chugg and Thomos R. Halford “Constant Modulus Orthogonal Frequency Division Multiplexing”, 2010 IEEE
Military communication conferenece.
[11] Intitive Guide to principles of communications www.complextoreal.co Copy Right 2002 Charan Langton.
Code dam Dcm RAC RCC F
Gold 1 0.0312 0.442 0.00021 2.213867
Walsh 1 0.3605 0.127 0.00979 0.637889
GDFT 0.342616 0.4545 0.454 0.01414 0.006053