Showing papers by "Sarat Kumar Patra published in 2012"
TL;DR: The result of the AdaBoost algorithm was compared with other algorithms such as Least Square, Best Linear Unbiased Estimator (BLUE), and Minimum Mean Square Error (MMSE) for channel estimation of Orthogonal Frequency Division Multiplexing systems.
Abstract: In this work we have applied Adapive Boosting (AdaBoost) for channel estimation of Orthogonal Frequency Division Multiplexing (OFDM) systems. The result of the AdaBoost algorithm was compared with other algorithms such Least Square (LS), Best Linear Unbiased Estimator (BLUE) and Minimum Mean Square Error (MMSE).
16 citations
TL;DR: In this paper, a planar antenna with 3.5/5/8.2 GHz triple band-notched characteristics was proposed for ultrawide band (UWB) applications.
Abstract: This article presents the compact planar antenna with 3.5/5.5/8.2 GHz triple band-notched characteristics. The antenna consists of an octagon shape patch with 50 Ω transmission line. By etching two C-shaped slots in the patch and adding pair of L-shaped resonator coupled to the radiating patch, band-rejected filtering properties in the WiMAX/WLAN/ITU bands are achieved. The proposed ultrawide band (UWB) antenna is optimized to operate in the frequency band from 3 to 11 GHz for VSWR < 2. Measured results confirm that the antenna is suitable for UWB applications because of its compact size and high performance. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:539–543, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26581
8 citations
15 Mar 2012
TL;DR: This paper analyzes how PAPR reduction is achieved using selected mapping (SLM) technique and simultaneously without sending the side information (SI) along with the OFDM symbol to WiMAX standard IEEE 802.16e.
Abstract: WiMAX with its standard IEEE 802.16d/e is the advanced technology used for long range communication with high data rate. It is well known that theorthogonal frequency division multiplexing (OFDM) is a promising technique for getting high data rate in multi path fading environment. Hence the physical layer of WiMAX uses OFDM. But the main disadvantage of OFDM is the high peak to average power ratio (PAPR). In this paper we analyze how PAPR reduction is achieved using selected mapping (SLM) technique and simultaneously without sending the side information (SI) along with the OFDM symbol. Here the PAPR performance using complimentary cumulative distribution function (CCDF) plot and the probability of SI detection error performance have been evaluated as the criteria for WiMAX standard IEEE 802.16e.
8 citations
15 Mar 2012
TL;DR: A theoretical review on the design of encoder and decoder for the Block codes followed by the fundamentals of various modified Block codes and it is shown that LDPC coded OFDM provides very low bit error rate compared to OFDM without coding case with a gain in transmitter power and thus making the link power efficient.
Abstract: OFDM with Quadrature amplitude modulation (QAM) technique can be used for high speed optical applications. As the order of modulation increases, the bit error rate (BER) increases. Forward Error correction (FEC) coding like LDPC coding is generally used to Improve BER performance. LDPC provides large minimum distance and also the power efficiency of the LDPC code increases significantly with the code length. Here we have given a theoretical review on the design of encoder and decoder for the Block codes followed by the fundamentals of various modified Block codes. Finally using a long Irregular LDPC code, it is shown that LDPC coded OFDM provides very low bit error rate compared to OFDM without coding case with a gain in transmitter power and thus making the link power efficient.
7 citations
TL;DR: A long Irregular LDPC coded OFDM with soft decision decoding provides very lower bit error rate as well as a larger gain in transmitter power and thus making the link more power efficient than the case with hard decision decoding.
Abstract: OFDM with quadrature amplitude modulation (QAM) technique can be used for high speed optical applications. Increasing the order of modulation, the bit error rate (BER) increases. Forward Error correction (FEC) coding like LDPC coding is generally used to improve the BER performance. LDPC provides large minimum distance and also the power efficiency of the LDPC code increases significantly with the code length. In this paper we have compared the Soft decision and Hard decision algorithms of LDPC codes. A long Irregular LDPC code is simulated over the BIAWGN channel demonstrating the fact that LDPC coded OFDM with soft decision decoding provides very lower bit error rate as well as a larger gain in transmitter power and thus making the link more power efficient than the case with hard decision decoding. Through simulation, we have shown the advantages of using this long Irregular LDPC coded OFDM link in Optical wireless communication (OWC).
6 citations
Journal Article•
20 Jun 2012-World Academy of Science, Engineering and Technology, International Journal of Electrical, Computer, Energetic, Electronic and Communication Engineering
TL;DR: Simulation results suggest that the performance of the proposed system is superior to many existing systems, and the significance of cross-correlation factor in alleviating multi-access interference is also discussed.
Abstract: The successful use of CDMA technology is based on the construction of large families of encoding sequences with good correlation properties. This paper discusses PN sequence generation based on Residue Arithmetic with an effort to improve the performance of existing interference-limited CDMA technology for mobile cellular systems. All spreading codes with residual number system proposed earlier did not consider external interferences, multipath propagation, Doppler effect etc. In literature the use of residual arithmetic in DS-CDMA was restricted to encoding of already spread sequence; where spreading of sequence is done by some existing techniques. The novelty of this paper is the use of residual number system in generation of the PN sequences which is used to spread the message signal. The significance of cross-correlation factor in alleviating multi-access interference is also discussed. The RNS based PN sequence has superior performance than most of the existing codes that are widely used in DS-CDMA applications. Simulation results suggest that the performance of the proposed system is superior to many existing systems. Keywords—Direct-Sequence Code Division Multiple Access (DSCDMA), Multiple-Access Interference (MAI), PN Sequence, Residue Number System (RNS).
6 citations
Proceedings Article•
30 Mar 2012TL;DR: A novel RWA algorithm considering BER constraints due to non-ideal wavelength de-multiplexing and space switching at each node of an optical WDM/DWDM network is proposed.
Abstract: In this paper, the impact of in-band crosstalk on transmission performance of a transparent WDM/DWDM network incorporating optical add drop multiplexer & space switches is studied. Error probabilities and power penalties produced by crosstalk are investigated. A traditional RWA scheme pays a little regard to the physical layer impairments and cannot provide optimized network performance in practical networks. Here we proposed a novel RWA algorithm considering BER constraints due to non-ideal wavelength de-multiplexing and space switching at each node of an optical WDM/DWDM network.
6 citations
TL;DR: This work explores how to compute a fine-grained QoS for dynamic OVPN connection request based on system components such as connectors, splices, etc by applying the virtual private network concept to WDM.
Abstract: Traditional optical networks such as synchronous optical network/synchronous digital hierarchy (SONET/SDH) have been perceived as high transmission rate networks without providing any QoS to different connection request. Recently, some attention has been given to coarse-grain QoS using differentiated optical services. Some designs for static VPN have been proposed in literature. However, little research work has been considered to provide dynamic VPN on optical networks. By applying the virtual private network concept to WDM, which is called as Optical Virtual Private Network (OVPN), we explore how to compute a fine-grained QoS for dynamic OVPN connection request based on system components such as connectors, splices, etc. An important problem in WDM network design is to construct an algorithm to determine the optimal OVPN Connection from a set of possible connections in a network topology, which can maximize the quality of service to the OVPN clients. By keeping that in mind, we proposed a method...
5 citations
01 Dec 2012
TL;DR: Subtractive Clustering with ANFIS based adaptive technique is proposed so that it works intelligently to select particular radio configuration and is seen to be better than the neural network and AnFIS scheme.
Abstract: Cognitive radio has emerged as intelligent wireless technology for solving the ever-growing demand of radio spectrum.Cognitive radio is a context aware radio, capable of observing the channel and networks parameters and make autonomously decisions on the best transceiver configuration. Cognitive radio can be made adaptive by utilizing intelligent software techniques. In this paper, we propose Subtractive Clustering with ANFIS based adaptive technique so that it works intelligently to select particular radio configuration. The system considers different time zones and subtractive clustering is used to assist ANFIS in selecting optimum number of rules and membership function. The performance of this is seen to be better than the neural network and ANFIS scheme. KeywordsCognitive radio (CR), spectrumhole, cognition cycle, ANFIS, subtractive clustering, extended scheme
5 citations
01 Dec 2012
TL;DR: Subtractive Clustering with ANFIS based adaptive technique is proposed so that it works intelligently to select particular radio configuration and is seen to be better than the neural network andANFIS scheme.
Abstract: Cognitive radio has emerged as intelligent wireless technology for solving the ever-growing demand of radio spectrum Cognitive radio is a context aware radio, capable of observing the channel and networks parameters and make autonomously decisions on the best transceiver configuration Cognitive radio can be made adaptive by utilizing intelligent software techniques In this paper, we propose Subtractive Clustering with ANFIS based adaptive technique so that it works intelligently to select particular radio configuration The system considers different time zones and subtractive clustering is used to assist ANFIS in selecting optimum number of rules and membership function The performance of this is seen to be better than the neural network and ANFIS scheme
5 citations
TL;DR: A centralized OVPN control mechanism over DWDM/GMPLS network based on the existing OVPN traffic is presented and it is important to understand the process that provide the QoS information to the centralized Traffic control manager.
Abstract: Due to the demand of clients, the service provider network needs to provide functionalities such as dynamic OVPN connection provisioning, de-provisioning and rerouting in order to provide guaranteed Quality of service (QoS). In corporate with that, we present a centralized OVPN control mechanism over DWDM/GMPLS network based on the existing OVPN traffic. It is important to understand the process that provide the QoS information to the centralized Traffic control manager and use this information efficiently to compute feasible OVPN connection for the prospective of client OVPN connection requirements.
01 Jan 2012
TL;DR: The design methodology says how to understand the process that provide PLI information to the control plane protocols and use this information efficiently to compute feasible connections to satisfy OVPN client's necessary requirement of QoS.
Abstract: In optic al virtual private network (OVPN), the quality of connection depends not only on network layer information, but also on physical layer impairments (PLIs) constraints, which are incurred by non-ideal optical transmission media and accumulates along with the optical connection. It is important to analysis PLIs in-order to satisfy OVPN client's necessary requirement of QoS for their connection setup. In-corporate to the above point, the design methodology says how to understand the process that provide PLI information to the control plane protocols and use this information efficiently to compute feasible connections. Based on the PLI constraints, it is proposed a centralized PLI based routing algorithm for the selection of OVPN connections.
TL;DR: A centralised PLI-based routing algorithm is proposed for the selection of data-paths based on the PLI impairments like fibre attenuation, Chromatic Dispersion and Polarisation Mode Dispersion, which reflects the Quality of service factors (Q-Factor).
Abstract: In optical networks, Physical Layer Impairments (PLIs) incurred by non-ideal optical transmission media accumulate along the optical path. The overall effect of PLIs determines the feasibility of the light-paths. It is important to understand the process that provide PLI information to the central manager and use this information efficiently to compute feasible routes and wavelengths. Based on the PLI impairments like fibre attenuation, Chromatic Dispersion (CD) and Polarisation Mode Dispersion (PMD), which reflects the Quality of service factors (Q-Factor); a centralised PLI-based routing algorithm is proposed for the selection of data-paths.
01 Jan 2012
TL;DR: The goal of the work is to dynamically provide a best OVPN connection during frequent arrival of connection requests with QoS requirements with the effect of polarization mode dispersion for the computation of Q-Factors which is prominent effect at high speed networks.
Abstract: Due to high demand of optical virtual private network (OVPN) connection setup with guaranteed quality of service (QoS) requirement, it is necessary to provide such application by the provider network. In order to support this we propose a QoS based OVPN connection set up mechanism over WDM network to the end customer, which also maintains the minimum blocking probability. The proposed WDM network model can be specified in terms of QoS parameters such as bandwidth and delay. We estimated those QoS parameters based on available resources and QoS requirements in terms of quality factor (Q-Factor). In this mechanism the OVPN connections also can be created or deleted according to the availability of the resources. In this paper we have considered the effect of polarization mode dispersion for the computation of Q-Factors which is prominent effect at high speed networks. The goal of the work is to dynamically provide a best OVPN connection during frequent arrival of connection requests with QoS requirements. .
01 Nov 2012
TL;DR: This paper presents a general purpose and easily configurable fuzzy logic based controller which can work with 4 inputs and generates a control action based on the knowledge base and analyses the system performance with reference to the Fuzzy Logic Toolbox of Matlab.
Abstract: A Fuzzy Logic Controller (FLC) is designed with heuristic knowledge of the plant. There are several application based Fuzzy Logic Controllers in literature. However, application specific controllers lack reusability and are expensive, if not produced in bulk. This paper presents a general purpose and easily configurable fuzzy logic based controller which can work with 4 inputs and generates a control action based on the knowledge base. Expert operator knowledge can also be directly programmed into the knowledge base (also known as rule base) of the designed controller without ceasing the control operation. The ease of file handling and user interactivity of DSP processors is heavily exploited and TMS320C6713 DSP was chosen as the hardware platform. Further this paper also analyses the system performance with reference to the Fuzzy Logic Toolbox of Matlab.
TL;DR: The little dependence of BER performance on various channels is explored here along with the conjecture of the concept of computational cutoff rate that represents an upper limit on rate of transmission for practically instrumentable reliable communications.
Abstract: A long Irregular LDPC code that performs at rates extremely close to the Shannon capacity has been taken. The code has carefully chosen degree patterns. Simulations has been done with Hard and Soft-decision decoding to compare the performance of this code with the rates 1/2 ,1/3, 1/4 ,2/3 ,2/5, 3/4, 3/5, 4/5, 5/6, 8/9 and 9/10 over various channels like AWGN channel, Rayleigh fading channel and Rician fading channel. The little dependence of BER performance on various channels is explored here along with the conjecture of the concept of computational cutoff rate that represents an upper limit on rate of transmission for practically instrumentable reliable communications . General Terms Orthogonal frequency division multiplexing (OFDM), Quadrature Amplitude Modulation (QAM) Keywords LDPC (Low Density parity check), Upper Bound, Cut off Rate, Bhattacharyya bound, Hard-decision, Soft-decision 1. INTRODUCTION For any channel, the bandwidth, data rate, noise and error rate are related to each other. The greater the bandwidth, the greater will be the cost. All transmission channels of any practical interest are limited in bandwidth due to the constrained physical properties of the transmission medium. For digital data transmission, in order to use bandwidth efficiently it is required to get higher possible data rate at a particular limit of error rate for a given bandwidth and to which the main constraint is the noise. If binary signals are transmitted then the supported data rate will be twice the bandwidth. But, using multilevel signaling the data rate can be increased by a factor of log
01 Dec 2012
TL;DR: A novel, reduced complexity implementation of the Partial Transmit Sequence technique for reducing the Peak to Average Power Ratio (PAPR) of OFDM signals by reducing the number of IFFT blocks and replacing parallel processing by serial processing reduces the computational complexity.
Abstract: This paper discusses a novel, reduced complexity implementation of the Partial Transmit Sequence technique (PTS) for reducing the Peak to Average Power Ratio (PAPR) of OFDM signals. The original PTS provides good PAPR reduction at the cost of computational complexity. The use of large number of IFFT blocks in PTS has been replaced by a single IFFT block. The parallel processing of the PTSs has been replaced by serial processing. Reducing the number of IFFT blocks and replacing parallel processing by serial processing reduces the computational complexity. The simulation results demonstrate that the proposed technique provides performance as good as standard PTS.
21 Mar 2012
TL;DR: The paper discusses the improvement in blocking probably for incoming requests while performing routing by proposed algorithm and the traditional shortest path algorithm.
Abstract: In this paper, we explore the issue of connection provisioning and performance analysis in WDM network ensuring the QoS requirement of the connection requests from the client in the network Each connection request can be specified with a Q-Factor requirement which is defined in terms of bandwidth and delay associated with the light path The paper discusses the improvement in blocking probably for incoming requests while performing routing by proposed algorithm and the traditional shortest path algorithm
01 Oct 2012
Book•
22 Sep 2012
TL;DR: This thesis work shows that RNS based PN sequence has enhanced performance to that of other CDMA codes by comparing the bit error probability in multi- user and multipath environment thus contributing a little towards the evolution of next generation CDMA technology.
Abstract: Code Division Multiple Access (CDMA) based on Spread Signal (SS) has emerged as one of the most important multiple access technologies for Second Generation
(2G) and Third Generation (3G) wireless communication systems by its wide applications in many important mobile cellular standards. CDMA technique relies on spreading codes to separate dierent users or channels and its properties will govern the performance of the system. So many of the problems of communication systems based on CDMA technology stem from the spreading codes/sequences, which includes two sub-categories, one being the orthogonal codes, such as Walsh Hadamard (WH) codes and Orthogonal Variable Spreading Factor (OVSF) codes, and the other being pseudo-noise or Pseudo Random (PN) sequences, such as Gold sequences, Kasami sequences, m-sequences, etc. In this thesis a PN sequence generation based on Residue Arithmetic is investigated with an eort to improve the performance of existing interference-limited CDMA technology for mobile cellular systems. This interference-limited performance is due to the fact that all the existing CDMA codes used in mobile cellular standards does not consider external interferences, multipath propagation, Doppler eect etc. So the non-ideal correlation properties of the pseudo-random CDMA codes results in MAI when used in a multi-user system. The PN codes appear random yet they are completely deterministic in nature with a small set of initial conditions. Consequently this work focuses on CDMA code design approach based on Residue Number System (RNS) which should take into account as many real operational conditions as possible and to maintain a suciently large code set size.First, the thesis reviews RNS, DS-CDMA and CDMA codes that are already implemented in various mobile cellular standards. Then the new PN Sequencegenerator design based on RNS is discussed. Comparison of the generated PN sequence with respect to other standard sequence is done in terms of number of
codes and correlation properties. Monte-Carlo simulations with the generated sequence are carried out for performance analysis under multi-path environment. The system has been evaluated in AWGN, Rayleigh Fading channel and dierent
Stationary Multipath Channels for dierent cross-correlation threshold. It is known that orthogonal Codes are used to multiplex more than one signal for downlink transmission over cellular networks. This downlink transmission is
prone to self interference caused by the loss of orthogonality between spreading codes due to multipath propagation. This issue is investigated in detail with
respect to WCDMA standards, which is very good representative for CDMA based 3G mobile cellular systems where the channelization code is OVSF code. The code assignment blocking (CAB) (If a particular code in the tree is used in a cell, then all its parent codes and child codes should not be used in the same cell to maintain orthogonality among the users) problem of OVSF codes restricts the number of available codes for a given cell. Since the 3rd generation WCDMA mobile communication systems apply the same multiple access technique, the generated sequence can also be the channelization code for downlink WCDMA system to mitigate the the same. The performance of the system is compared with Walsh Hadamard code over multipath AWGN and dierent Fading channels. This thesis work shows that RNS based PN sequence has enhanced performance
to that of other CDMA codes by comparing the bit error probability in multi- user and multipath environment thus contributing a little towards the evolution of next generation CDMA technology.