Symbol Timing Estimation in Multiband Orthogonal Frequency Division Multiplexing based Ultrawide band System

Hafiz, None

doi:10.3844/ajassp.2012.505.509

Cited by 3 publications

(3 citation statements)

References 10 publications

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“…Because of the algorithm's recursive nature, it can run in real time using only the present input measurements and the previously calculated state; no additional past information is required (Nasseri and Bakhshi, 2010). From a theoretical standpoint, the main assumption of the Kalman filter is that the underlying system is a linear dynamical system and that all error terms and measurements have a Gaussian distribution (Schafhuber et al, 2003;Suresh et al, 2012).…”

Section: Kalman Filtering Algorithmmentioning

confidence: 99%

Enhanced Channel Estimation and Performance Analysis Using H-Infinity Filter for MIMO-Orthogonal Frequency Division Multiplexing Systems

Sekar¹,

Sankarappan²

2015

Journal of Computer Science

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This paper, deals with H-infinity channel estimation technique for Orthogonal Frequency Division Multiplexing (OFDM) systems, in fading channel. Channel estimation is important for wireless applications because, in practical transmission scenario, channel correlation functions are either not known or cannot be easily estimated. It is therefore desirable to have an estimator which is robust to mismatches between the assumed and the actual channel correlation functions. The wireless channel has fading characteristics and its time varying nature adds additional cost to estimator design. A simplified Kalman filter is proposed which reduces the noise effects of the least square estimation. While the Kalman filtering algorithm requires the noise process to be zero mean besides the requirement to know the standard deviation of the noise process, H-infinity filtering algorithm makes no assumption about the noise and hence is said to be more robust in the wake of uncertainty. The proposed channel estimation algorithm is more robust in terms of model uncertainty and is more suitable for OFDM systems. Further, the complexity of the H-infinity filter is not too high. Given the conditions, H-infinity poses a suitable filter than any other, for channel estimation.

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Section: Kalman Filtering Algorithmmentioning

confidence: 99%

Enhanced Channel Estimation and Performance Analysis Using H-Infinity Filter for MIMO-Orthogonal Frequency Division Multiplexing Systems

Sekar¹,

Sankarappan²

2015

Journal of Computer Science

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“…In February 2002, the Federal Communication Committee (FCC) approved the First Report and Order (R and O) for commercial use of UWB technology under strict power emission limits for various devices. The UWB signals must have an average power spectral density not more than -41 dBm/MHz in the 3.1-10.6 GHz band and a bandwidth greater than 500 MHz or fractional bandwidth larger than 20 percent at all times of transmission (Kim et al, 2010;Suresh et al, 2012). Since FCC force stringent power-emission limitations at the transmitter and due to the additional transmission path loss, the received UWB signal exhibits very low Power Spectral Density (PSD) at the receiver antenna.…”

Section: Introductionmentioning

confidence: 99%

A 2-12 GHz Low Noise Amplifier Design for Ultra Wide Band Applications

Vaithianathan¹,

Raja²,

Srinivasan³

2012

American Journal of Applied Sciences

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Problem statement: The Low Noise Amplifier (LNA) is a core block of an Ultra Wide Band (UWB) receiver since it amplifies a very weak signal received at the antenna to acceptable levels while introducing less self-generated noise and distortions. The LNA design poses a unique challenge as it requires simultaneous optimization of various performance parameters like power gain, input matching, noise figure, power consumption and linearity over the entire UWB band. Approach: In this study, a three stage LNA is proposed with a resistive current reuse network as a first stage, a cascode amplifier with shunt-series peaking and a local active feedback as a second stage and a voltage buffer as a third stage. A resistive current reuse network is used to achieve better linearity, low noise figure, better input matching with lesser power consumption. A cascode stage with shunt-series peaking and a local active feedback is used to enhance the bandwidth and reverse isolation. A voltage buffer is used as an output stage to achieve better output matching. Results: The proposed LNA is designed using 0.18 Âµm CMOS technology and is simulated to verify its performance. It achieves a power gain of greater than 17.3 dB, a noise figure less than 2.45 dB with an input matching less than -11.2 dB over a 3-dB bandwidth of 2-12 GHz. The achieved output matching is below -12 dB, the reverse isolation is below -68 dB with a Rolletâs stability factor is greater than 1000 to ensure better stability. This LNA also ensures better linearity with an IIP₃ of 3 dBm at 7.5 GHz with low power consumption of 10.7 mW. Conclusion/Recommendations: From the simulation results it is evident that the presented LNA claims the advantages of very high gain, better input matching with low noise figure and less power consumption.

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“…Kumaran et al (2013) analyzed the performance of OFDM based bidirectional relay network which employs Physical Layer Network Coding (PLNC) in the presence of phase noise. Suresh et al (2012) proposed a novel method to estimate fine symbol timing error for MB-OFDM based UWB system which will be suitable for MB-OFDM receivers for UWB positioning and UWB communication.…”

Section: Introductionmentioning

confidence: 99%

Analysis of Reduction in Complexity of Multiple Input- Multiple Output-Orthogonal Frequency Division Multiplexing Systems With Carrier Frequency Offset Estimation and Correction

Gauni¹,

Kumar²

2014

Journal of Computer Science

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Orthogonal Frequency Division Multiplexing (OFDM) is a promising research area in WirelessCommunication for high data rates. The Multiple Input-Multiple Output (MIMO) technology when incorporated with the OFDM system promise a significant boost in the performance. But, the MIMO-OFDM systems are very sensitive to Carrier Frequency Offset (CFO) as it deteriorates the system performance with the rise of Inter-Carrier-Interference (ICI). A theoretical analysis to evaluate the performance of Orthogonal Frequency Division Multiplexing (OFDM) systems is done here, under the combined influence of phase offset and frequency offset over rayleigh, Weibull and Nakagami fading channels using Binary Phase Shift Keying (BPSK) Modulation. The analysis of increase in Bit Error Rate (BER) caused by the presence of phase offset and frequency offset is evaluated assuming Gaussian probability density function. Hence the estimation and correction of CFO plays a vital role in MIMO-OFDM systems. A method for CFO estimation and correction is analyzed in the MIMO-OFDM system with 16-QAM modulation. In non-pilot-aided systems the CFO acquisition is done using Maximum Likelihood Estimation (MLE) algorithm. The proposed scheme uses the same block for CFO correction of MIMO-OFDM symbols. Since the same phase calculation block is used for the ML estimation along with the acquisition, the computational cost and the complexity of implementation is reduced.

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Symbol Timing Estimation in Multiband Orthogonal Frequency Division Multiplexing based Ultrawide band System

Cited by 3 publications

References 10 publications

Enhanced Channel Estimation and Performance Analysis Using H-Infinity Filter for MIMO-Orthogonal Frequency Division Multiplexing Systems

Enhanced Channel Estimation and Performance Analysis Using H-Infinity Filter for MIMO-Orthogonal Frequency Division Multiplexing Systems

A 2-12 GHz Low Noise Amplifier Design for Ultra Wide Band Applications

Analysis of Reduction in Complexity of Multiple Input- Multiple Output-Orthogonal Frequency Division Multiplexing Systems With Carrier Frequency Offset Estimation and Correction

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