의석 심 - Academia.edu (original) (raw)

Papers by 의석 심

Research paper thumbnail of Pilot Subset Partitioning Based Integer Frequency Offset Estimation for OFDM Systems With Cyclic Delay Diversity

Ieee Transactions on Broadcasting, Dec 1, 2010

Cyclic delay diversity (CDD) is a simple transmit diversity technique for coded OFDM systems with... more Cyclic delay diversity (CDD) is a simple transmit diversity technique for coded OFDM systems with multiple transmit antennas. However, high frequency selectivity caused by CDD degrades the performance of post-FFT estimation, i.e., integer frequency offset (IFO). This paper suggests a simple way of improving the performance of the IFO estimator based on the pilot subset partitioning which is designed to reduce the effect of frequency selective fading by adopting the CDD. By partitioning uncorrelated pilot subcarriers into subsets to satisfy high correlation, and performing frequency estimation for each pilot subset, a robust IFO estimation scheme is derived. The simulation results show that the proposed method can provide benefit to the overall system performance.

Research paper thumbnail of A simple IQ imbalance compensation scheme for OFDM systems

2008 14th Asia Pacific Conference on Communications, 2008

... Hyun Yang Eu-Suk Shim Hyoung-Kyu Song and Young-Hwan You uT Communication Research Institute ... more ... Hyun Yang Eu-Suk Shim Hyoung-Kyu Song and Young-Hwan You uT Communication Research Institute Sejong University, Korea Email: yhyou@sejong.ac.kr ... of the FFf of receiver during the l-th period in the presence of IQ mismatch is given by l'l(k) == UHl(k)Xl(k) +vHt(N - k)Xt ...

Research paper thumbnail of OFDM Timing Estimation Method without Training Symbol

Ieice Transactions on Communications, May 1, 2006

Research paper thumbnail of GI-Based Estimation of Integer Carrier Offset for Multicarrier Transmission Systems

Ieice Transactions on Communications, Dec 1, 2006

ABSTRACT

Research paper thumbnail of Transmitter, Receiver and Method for Estimating Variable Frame Structure Using Preamble Signals

Research paper thumbnail of Improved pilot-symbol assisted estimation of integer frequency offset for OFDM system with cyclic delay diversity

2008 14th Asia Pacific Conference on Communications, Oct 1, 2008

... 0.2 CDrn c: 0 Co ~ (.) ~ i .= 0.1 ~c: ~u '0 CD ~ ll. ---+1I_ _-----___1.-r-~.-r---- -_ _... more ... 0.2 CDrn c: 0 Co ~ (.) ~ i .= 0.1 ~c: ~u '0 CD ~ ll. ---+1I_ _-----___1.-r-~.-r---- -_ _ et_ --et-- - - 8 1 -++J>-+--_____4i~----I+-+--~_+_+---+1r--~+__-82 ... (8), the IFO detector has the form Ai ~ argmax{ t ItHI,t(ki +r)e-j27Ck~t/N Irl~M i=l t=O X E Xl(k +r)Pt(k) kESi +~iWI(k)~*(k)l} ...

Research paper thumbnail of Low-Complexity Coarse Frequency Offset Estimation for OFDM Systems with Non-uniform Phased Pilots

Ieice Transactions on Fundamentals of Electronics Communications and Computer Sciences, 2011

Research paper thumbnail of The improved SFO estimation method for DRM Plus with cyclic delay diversity

2013 International Conference on ICT Convergence (ICTC), 2013

Research paper thumbnail of Parameter Estimation and Error Reduction in Multicarrier Systems by Time-Domain Spreading

Progress In Electromagnetics Research B, 2008

This paper suggests parameter estimation and error reduction scheme in a multicarrier transmissio... more This paper suggests parameter estimation and error reduction scheme in a multicarrier transmission system. A multicarrier orthogonal frequency division multiplexing (OFDM) signal by using a time-domain spreading (TDS) coupled with a cyclic time shift enables a pilot-less synchronization. Exploiting the modified OFDM signal endowed with the TDS, the proposed synchronization receiver can accurately estimate the carrier-frequency offset as well as the timing offset of OFDM signals without the use of training symbol.

Research paper thumbnail of Pilot-Less Synchronization Receiver for UWB-OFDM Systems

2008 IEEE 10th International Symposium on Spread Spectrum Techniques and Applications, 2008

Carrier frequency offset (CFO) is one of the most important problems in an orthogonal frequency d... more Carrier frequency offset (CFO) is one of the most important problems in an orthogonal frequency division mul- tiplexing (OFDM) system, which seriously degrades the perfor- mance of the systems due to its time-variant behavior. This paper suggests a pilot-less residual CFO estimator for ultra-wideband OFDM (UWB-OFDM) systems. The proposed scheme uses a time-domain spreaded data samples which is provided in UWB Wimedia OFDM system. To demonstrate the efficiency of the proposed pilot-less CFO estimator, analytical expression of the mean square error (MSE) is reported and comparisons are made with the conventional pilot-aided CFO estimator in terms of MSE, bit error rate (BER), and throughput.

Research paper thumbnail of Robust Integer Frequency Offset Estimation for OFDM System

The 2nd International Conference on Wireless Broadband and Ultra Wideband Communications (AusWireless 2007), 2007

Orthogonal frequency division multiplexing (OFDM) systems are highly sensitive to carrier frequen... more Orthogonal frequency division multiplexing (OFDM) systems are highly sensitive to carrier frequency offset and symbol timing error. This paper deals with estimation method of integer frequency offset (IFO) without the aid of pilot symbols. The proposed IFO estimator exploits two consecutive identical OFDM data symbols with only change of phase. To demonstrate the efficiency of the proposed IFO estimators, comparisons are made with other existing estimators in terms of error performance, estimation range, and complexity.

Research paper thumbnail of Frequency Estimation by Pilot Set Partitioning for Ofdm Systems with Multiple Transmit Antennas

Progress In Electromagnetics Research M, 2008

Cyclic delay diversity (CDD) is a simple approach to increase the frequency selectivity of the ch... more Cyclic delay diversity (CDD) is a simple approach to increase the frequency selectivity of the channel in an orthogonal frequency division multiplexing (OFDM) based transmission scheme. However, CDD can cause serious degradation in the performance of channel and frequency estimation in the frequency domain. This paper suggests a post-FFT frequency estimation scheme suitable for arbitrary cyclic delays in the CDD-OFDM system. By partitioning uncorrelated pilot subcarriers into subsets to be flat, and performing frequency estimation for each pilot subset, a robust integer frequency offset estimation scheme is derived.

Research paper thumbnail of OFDM Integer Frequency Offset Estimator in Rapidly Time-Varying Channels

2006 Asia-Pacific Conference on Communications, 2006

In this paper, we present a simple way of estimating the integer frequency offset of orthogonal f... more In this paper, we present a simple way of estimating the integer frequency offset of orthogonal frequency division multiplexing (OFDM) system over a rapidly time-varying channel. By utilizing the channel responses of neighboring subcarriers within one pilot symbol, the frequency offset estimator is derived. We show by simulation that the proposed estimator can accurately estimate the integer frequency offset with

Research paper thumbnail of Performance of MB-OFDM UWB Systems with Extra Diversity

The 2nd International Conference on Wireless Broadband and Ultra Wideband Communications (AusWireless 2007), 2007

ABSTRACT

Research paper thumbnail of An Improved Autocorrelation Based Single Frequency Estimator with Reduced Complexity

The 2nd International Conference on Wireless Broadband and Ultra Wideband Communications (AusWireless 2007), 2007

ABSTRACT

Research paper thumbnail of Improved Pilot Symbol-Assisted Estimation of Integer Frequency Offset for OFDM

The 2nd International Conference on Wireless Broadband and Ultra Wideband Communications (AusWireless 2007), 2007

ABSTRACT

Research paper thumbnail of A Residual and Sampling Frequency Offset Estimation Scheme for Multiband OFDM

The 2nd International Conference on Wireless Broadband and Ultra Wideband Communications (AusWireless 2007), 2007

In this paper, a residual frequency offset (RFO) and sampling frequency offset (SFO) estimator is... more In this paper, a residual frequency offset (RFO) and sampling frequency offset (SFO) estimator is proposed for ultra- wideband multi-band orthogonal frequency division multiplexing (UWB MB-OFDM) systems. The proposed scheme uses a time-domain spreaded data samples which is provided in MB-OFDM system. To demonstrate the efficiency of the proposed RFO and SFO estimator, comparisons are made with other existing estimator.

Research paper thumbnail of Synchronization Receiver for OFDM-Based FM Broadcasting Systems

Wireless Personal Communications, 2011

The digital radio mondiale (DRM) consortium is now preparing to test and verify the design of DRM... more The digital radio mondiale (DRM) consortium is now preparing to test and verify the design of DRM plus, prior to standardization, produce a revision to the existing DRM system specification. This paper presents an overview of the OFDM-based DRM system, planned to operate in FM bands, utilizing important receiver aspects, such as timing and frequency synchronization, which can provide benefits to the overall system performance. In particular, algorithms are devised or selected for the sequential estimation of symbol timing and carrier frequency offsets by exploiting the structure of the data and pilot. The performance of using the proposed algorithms is demonstrated via several examples in the channel models for FM bands.

Research paper thumbnail of A Frame Detector for Zero-Padded OFDM Systems

IEICE Transactions on Communications, 2006

ABSTRACT

Research paper thumbnail of Low-overhead sampling clock frequency synchronization for OFDM-based DRM systems

IEICE Electronics Express, 2010

In this paper, an improved and low-complexity sampling clock frequency offset (SFO) estimation sc... more In this paper, an improved and low-complexity sampling clock frequency offset (SFO) estimation scheme is proposed for orthogonal frequency division multiplexing (OFDM) based digital radio mondiale (DRM) systems. In order to devise the low-complexity SFO estimator, some modifications on the conventional estimator are highlighted with an emphasis on the selection of pilot subcarrier.

Research paper thumbnail of Pilot Subset Partitioning Based Integer Frequency Offset Estimation for OFDM Systems With Cyclic Delay Diversity

Ieee Transactions on Broadcasting, Dec 1, 2010

Cyclic delay diversity (CDD) is a simple transmit diversity technique for coded OFDM systems with... more Cyclic delay diversity (CDD) is a simple transmit diversity technique for coded OFDM systems with multiple transmit antennas. However, high frequency selectivity caused by CDD degrades the performance of post-FFT estimation, i.e., integer frequency offset (IFO). This paper suggests a simple way of improving the performance of the IFO estimator based on the pilot subset partitioning which is designed to reduce the effect of frequency selective fading by adopting the CDD. By partitioning uncorrelated pilot subcarriers into subsets to satisfy high correlation, and performing frequency estimation for each pilot subset, a robust IFO estimation scheme is derived. The simulation results show that the proposed method can provide benefit to the overall system performance.

Research paper thumbnail of A simple IQ imbalance compensation scheme for OFDM systems

2008 14th Asia Pacific Conference on Communications, 2008

... Hyun Yang Eu-Suk Shim Hyoung-Kyu Song and Young-Hwan You uT Communication Research Institute ... more ... Hyun Yang Eu-Suk Shim Hyoung-Kyu Song and Young-Hwan You uT Communication Research Institute Sejong University, Korea Email: yhyou@sejong.ac.kr ... of the FFf of receiver during the l-th period in the presence of IQ mismatch is given by l'l(k) == UHl(k)Xl(k) +vHt(N - k)Xt ...

Research paper thumbnail of OFDM Timing Estimation Method without Training Symbol

Ieice Transactions on Communications, May 1, 2006

Research paper thumbnail of GI-Based Estimation of Integer Carrier Offset for Multicarrier Transmission Systems

Ieice Transactions on Communications, Dec 1, 2006

ABSTRACT

Research paper thumbnail of Transmitter, Receiver and Method for Estimating Variable Frame Structure Using Preamble Signals

Research paper thumbnail of Improved pilot-symbol assisted estimation of integer frequency offset for OFDM system with cyclic delay diversity

2008 14th Asia Pacific Conference on Communications, Oct 1, 2008

... 0.2 CDrn c: 0 Co ~ (.) ~ i .= 0.1 ~c: ~u '0 CD ~ ll. ---+1I_ _-----___1.-r-~.-r---- -_ _... more ... 0.2 CDrn c: 0 Co ~ (.) ~ i .= 0.1 ~c: ~u '0 CD ~ ll. ---+1I_ _-----___1.-r-~.-r---- -_ _ et_ --et-- - - 8 1 -++J>-+--_____4i~----I+-+--~_+_+---+1r--~+__-82 ... (8), the IFO detector has the form Ai ~ argmax{ t ItHI,t(ki +r)e-j27Ck~t/N Irl~M i=l t=O X E Xl(k +r)Pt(k) kESi +~iWI(k)~*(k)l} ...

Research paper thumbnail of Low-Complexity Coarse Frequency Offset Estimation for OFDM Systems with Non-uniform Phased Pilots

Ieice Transactions on Fundamentals of Electronics Communications and Computer Sciences, 2011

Research paper thumbnail of The improved SFO estimation method for DRM Plus with cyclic delay diversity

2013 International Conference on ICT Convergence (ICTC), 2013

Research paper thumbnail of Parameter Estimation and Error Reduction in Multicarrier Systems by Time-Domain Spreading

Progress In Electromagnetics Research B, 2008

This paper suggests parameter estimation and error reduction scheme in a multicarrier transmissio... more This paper suggests parameter estimation and error reduction scheme in a multicarrier transmission system. A multicarrier orthogonal frequency division multiplexing (OFDM) signal by using a time-domain spreading (TDS) coupled with a cyclic time shift enables a pilot-less synchronization. Exploiting the modified OFDM signal endowed with the TDS, the proposed synchronization receiver can accurately estimate the carrier-frequency offset as well as the timing offset of OFDM signals without the use of training symbol.

Research paper thumbnail of Pilot-Less Synchronization Receiver for UWB-OFDM Systems

2008 IEEE 10th International Symposium on Spread Spectrum Techniques and Applications, 2008

Carrier frequency offset (CFO) is one of the most important problems in an orthogonal frequency d... more Carrier frequency offset (CFO) is one of the most important problems in an orthogonal frequency division mul- tiplexing (OFDM) system, which seriously degrades the perfor- mance of the systems due to its time-variant behavior. This paper suggests a pilot-less residual CFO estimator for ultra-wideband OFDM (UWB-OFDM) systems. The proposed scheme uses a time-domain spreaded data samples which is provided in UWB Wimedia OFDM system. To demonstrate the efficiency of the proposed pilot-less CFO estimator, analytical expression of the mean square error (MSE) is reported and comparisons are made with the conventional pilot-aided CFO estimator in terms of MSE, bit error rate (BER), and throughput.

Research paper thumbnail of Robust Integer Frequency Offset Estimation for OFDM System

The 2nd International Conference on Wireless Broadband and Ultra Wideband Communications (AusWireless 2007), 2007

Orthogonal frequency division multiplexing (OFDM) systems are highly sensitive to carrier frequen... more Orthogonal frequency division multiplexing (OFDM) systems are highly sensitive to carrier frequency offset and symbol timing error. This paper deals with estimation method of integer frequency offset (IFO) without the aid of pilot symbols. The proposed IFO estimator exploits two consecutive identical OFDM data symbols with only change of phase. To demonstrate the efficiency of the proposed IFO estimators, comparisons are made with other existing estimators in terms of error performance, estimation range, and complexity.

Research paper thumbnail of Frequency Estimation by Pilot Set Partitioning for Ofdm Systems with Multiple Transmit Antennas

Progress In Electromagnetics Research M, 2008

Cyclic delay diversity (CDD) is a simple approach to increase the frequency selectivity of the ch... more Cyclic delay diversity (CDD) is a simple approach to increase the frequency selectivity of the channel in an orthogonal frequency division multiplexing (OFDM) based transmission scheme. However, CDD can cause serious degradation in the performance of channel and frequency estimation in the frequency domain. This paper suggests a post-FFT frequency estimation scheme suitable for arbitrary cyclic delays in the CDD-OFDM system. By partitioning uncorrelated pilot subcarriers into subsets to be flat, and performing frequency estimation for each pilot subset, a robust integer frequency offset estimation scheme is derived.

Research paper thumbnail of OFDM Integer Frequency Offset Estimator in Rapidly Time-Varying Channels

2006 Asia-Pacific Conference on Communications, 2006

In this paper, we present a simple way of estimating the integer frequency offset of orthogonal f... more In this paper, we present a simple way of estimating the integer frequency offset of orthogonal frequency division multiplexing (OFDM) system over a rapidly time-varying channel. By utilizing the channel responses of neighboring subcarriers within one pilot symbol, the frequency offset estimator is derived. We show by simulation that the proposed estimator can accurately estimate the integer frequency offset with

Research paper thumbnail of Performance of MB-OFDM UWB Systems with Extra Diversity

The 2nd International Conference on Wireless Broadband and Ultra Wideband Communications (AusWireless 2007), 2007

ABSTRACT

Research paper thumbnail of An Improved Autocorrelation Based Single Frequency Estimator with Reduced Complexity

The 2nd International Conference on Wireless Broadband and Ultra Wideband Communications (AusWireless 2007), 2007

ABSTRACT

Research paper thumbnail of Improved Pilot Symbol-Assisted Estimation of Integer Frequency Offset for OFDM

The 2nd International Conference on Wireless Broadband and Ultra Wideband Communications (AusWireless 2007), 2007

ABSTRACT

Research paper thumbnail of A Residual and Sampling Frequency Offset Estimation Scheme for Multiband OFDM

The 2nd International Conference on Wireless Broadband and Ultra Wideband Communications (AusWireless 2007), 2007

In this paper, a residual frequency offset (RFO) and sampling frequency offset (SFO) estimator is... more In this paper, a residual frequency offset (RFO) and sampling frequency offset (SFO) estimator is proposed for ultra- wideband multi-band orthogonal frequency division multiplexing (UWB MB-OFDM) systems. The proposed scheme uses a time-domain spreaded data samples which is provided in MB-OFDM system. To demonstrate the efficiency of the proposed RFO and SFO estimator, comparisons are made with other existing estimator.

Research paper thumbnail of Synchronization Receiver for OFDM-Based FM Broadcasting Systems

Wireless Personal Communications, 2011

The digital radio mondiale (DRM) consortium is now preparing to test and verify the design of DRM... more The digital radio mondiale (DRM) consortium is now preparing to test and verify the design of DRM plus, prior to standardization, produce a revision to the existing DRM system specification. This paper presents an overview of the OFDM-based DRM system, planned to operate in FM bands, utilizing important receiver aspects, such as timing and frequency synchronization, which can provide benefits to the overall system performance. In particular, algorithms are devised or selected for the sequential estimation of symbol timing and carrier frequency offsets by exploiting the structure of the data and pilot. The performance of using the proposed algorithms is demonstrated via several examples in the channel models for FM bands.

Research paper thumbnail of A Frame Detector for Zero-Padded OFDM Systems

IEICE Transactions on Communications, 2006

ABSTRACT

Research paper thumbnail of Low-overhead sampling clock frequency synchronization for OFDM-based DRM systems

IEICE Electronics Express, 2010

In this paper, an improved and low-complexity sampling clock frequency offset (SFO) estimation sc... more In this paper, an improved and low-complexity sampling clock frequency offset (SFO) estimation scheme is proposed for orthogonal frequency division multiplexing (OFDM) based digital radio mondiale (DRM) systems. In order to devise the low-complexity SFO estimator, some modifications on the conventional estimator are highlighted with an emphasis on the selection of pilot subcarrier.