The Experts below are selected from a list of 9078 Experts worldwide ranked by ideXlab platform
Markus Rupp - One of the best experts on this subject based on the ideXlab platform.
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ICASSP - On Pilot-Symbol aided channel estimation in FBMC-OQAM
2016 IEEE International Conference on Acoustics Speech and Signal Processing (ICASSP), 2016Co-Authors: Ronald Nissel, Markus RuppAbstract:Filter bank multicarrier modulation is considered as a possible candidate for 5G. In this paper, we consider Pilot-Symbol aided channel estimation and address the problem of canceling the imaginary interference at the Pilot positions. We develop a matrix formulation for the transmission system which allows us to formulate general conditions on the auxiliary Pilot Symbols, capturing also the interde-pendency of closely spaced Pilots and an arbitrary number of auxiliary Pilot Symbols. By using two auxiliary Symbols per Pilot instead of one, we are able to improve the peak-to-average power ratio as well as the achievable capacity for small to medium signal-to-noise ratios. The achievable capacity can further be increased by interference cancellation based on linear precoding for which we propose an algorithm to find the coding matrix required. Finally, we compare auxiliary Pilot Symbols and linear precoding in terms of complexity and performance.
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bit error probability for Pilot Symbol aided ofdm channel estimation in doubly selective channels
International ITG Workshop on Smart Antennas, 2014Co-Authors: Ronald Nissel, Michal Simko, Martin Lerch, Markus RuppAbstract:In this paper, we derive a closed-form expression for the Bit Error Probability (BEP) of an orthogonal frequencydivision multiplexing system that utilizes Pilot-Symbol-aided channel estimation. We assume Rayleigh fading, additive white Gaussian noise, and that the interpolation is linear but otherwise completely arbitrary. It is shown that the minimum mean squared error interpolation also minimizes the BEP. For a Signal-to-Interference Ratio (SIR) smaller than the signal-to-noise ratio, simulations confirm our analytical results. However, for higher SIR they exhibit differences because the inter-carrier interference is not normally distributed, violating our assumptions.
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adaptive Pilot Symbol patterns for mimo ofdm systems
IEEE Transactions on Wireless Communications, 2013Co-Authors: Michal Simko, Paulo S R Diniz, Qi Wang, Markus RuppAbstract:Recent standards for cellular transmission systems offer a lot of flexibility, such as the choice of transmission modes, modulation alphabets, coding rates, and precoding matrices. Despite this trend, Pilot-Symbol patterns in today's standards remain fixed, although such an approach is suboptimal. In this paper, we show how to design optimal Pilot-Symbol patterns by maximizing an upper bound of a constrained capacity that takes channel estimation errors and Inter Carrier Interference into account. Furthermore, we propose adaptive Pilot-Symbol patterns that follow changing channel statistics. As a proof of concept, we present throughput simulation results of two competitive systems, a transmission system compliant with the Long Term Evolution (LTE)-standard and an improved system utilizing the proposed adaptive Pilot patterns. The transmission system utilizing adaptive Pilot patterns outperforms an LTE-standard compliant system in all considered scenarios. The throughput gain for a single input single output system ranges between 3% and 80%. For a 4 × 4 transmission system, the performance gain is significantly higher and can reach up to 850% compared to a conventional LTE system.
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WCNC - New insights in optimal Pilot Symbol patterns for OFDM systems
2013 IEEE Wireless Communications and Networking Conference (WCNC), 2013Co-Authors: Michal Simko, Paulo S R Diniz, Qi Wang, Markus RuppAbstract:Nowadays, most wireless communication systems utilize coherent detection which implies the necessity of multiplexing reference Symbols between data-Symbols for the purpose of channel estimation. In Long Term Evolution (LTE), these reference Symbols can consume up to 14.2% of the total bandwidth. In this work, we search for an optimal Pilot-Symbol pattern design using a post-equalization Signal to Interference and Noise Ratio (SINR) framework. We show how close to optimally choose the distance between adjacent Pilot-Symbols and how to distribute the available power between Pilot and data Symbol at the same time. We confirm the performance of our analytical solution by means of simulation. Compared to a system with a fixed distance between Pilot-Symbol and unit power distribution, the proposed system configuration yields a gain of around 30% in terms of capacity.
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optimal Pilot Symbol power allocation in lte
Vehicular Technology Conference, 2011Co-Authors: Michal Simko, Qi Wang, Stefan Pendl, Stefan Schwarz, Josep Colom Ikuno, Markus RuppAbstract:The UMTS Long Term Evolution (LTE) allows the Pilot Symbol power to be adjusted with respect to that of the data Symbols. Such power increase at the Pilot Symbols results in a more accurate channel estimate, but in turn reduces the amount of power available for the data transmission. In this paper, we derive optimal Pilot Symbol power allocation based on maximization of the post-equalization Signal to Interference and Noise Ratio (SINR) under imperfect channel knowledge. Simulation validates our analytical mode for optimal Pilot Symbol power allocation.
Lajos Hanzo - One of the best experts on this subject based on the ideXlab platform.
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generalized mimo transmit preprocessing using Pilot Symbol assisted rateless codes
Vehicular Technology Conference, 2010Co-Authors: N. Bonello, Sheng Chen, Du Yang, Lajos HanzoAbstract:In this paper, we propose a generalized multiple-input multiple-output (MIMO) transmit preprocessing system, where both the channel coding and the linear MIMO transmit precoding components exploit the knowledge of the channel. Moreover, we also propose a novel technique, hereby referred to as Pilot Symbol assisted rateless (PSAR) coding, where a predetermined fraction of binary Pilot Symbols is interspersed with the channel-coded bits at the channel coding stage, instead of multiplexing the Pilots with the data Symbols at the modulation stage, as in classic Pilot Symbol assisted modulation (PSAM). We will subsequently demonstrate that the PSAR code-aided transmit preprocessing scheme succeeds in gleaning more beneficial knowledge from the inserted Pilots, because the Pilot bits are not only useful for estimating the channel at the receiver, but they are also beneficial in terms of significantly reducing the computational complexity of the rateless channel decoder.
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VTC Spring - Generalized MIMO Transmit Preprocessing Using Pilot Symbol Assisted Rateless Codes
2010 IEEE 71st Vehicular Technology Conference, 2010Co-Authors: N. Bonello, Sheng Chen, Du Yang, Lajos HanzoAbstract:In this paper, we propose a generalized multiple-input multiple-output (MIMO) transmit preprocessing system, where both the channel coding and the linear MIMO transmit precoding components exploit the knowledge of the channel. Moreover, we also propose a novel technique, hereby referred to as Pilot Symbol assisted rateless (PSAR) coding, where a predetermined fraction of binary Pilot Symbols is interspersed with the channel-coded bits at the channel coding stage, instead of multiplexing the Pilots with the data Symbols at the modulation stage, as in classic Pilot Symbol assisted modulation (PSAM). We will subsequently demonstrate that the PSAR code-aided transmit preprocessing scheme succeeds in gleaning more beneficial knowledge from the inserted Pilots, because the Pilot bits are not only useful for estimating the channel at the receiver, but they are also beneficial in terms of significantly reducing the computational complexity of the rateless channel decoder.
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Generalized MIMO transmit preprocessing using Pilot Symbol assisted rateless codes
IEEE Transactions on Wireless Communications, 2010Co-Authors: N. Bonello, Sheng Chen, Du Yang, Lajos HanzoAbstract:In this paper, we propose a generalized multipleinput multiple-output (MIMO) transmit preprocessing system, where both the channel coding and the linear MIMO transmit precoding components exploit the knowledge of the channel. This was achieved by exploiting the inherently flexible nature of a specific family of rateless codes that are capable of modifying their code-rate as well as their degree distribution based on the channel state information (CSI), in an attempt to adapt to the time-varying nature of the channel. Moreover, we also propose a novel technique, hereby referred to as Pilot Symbol assisted rateless (PSAR) coding, where a predetermined fraction of binary Pilot Symbols is interspersed with the channel-coded bits at the channel coding stage, instead of multiplexing the Pilots with the data Symbols at the modulation stage, as in classic Pilot Symbol assisted modulation (PSAM). We will subsequently demonstrate that the PSAR code-aided transmit preprocessing scheme succeeds in gleaning more beneficial knowledge from the inserted Pilots, because the Pilot bits are not only useful for estimating the channel at the receiver, but they are also beneficial in terms of significantly reducing the computational complexity of the rateless channel decoder. Our results suggest that more than a 30% reduction in the decoder's computational complexity can be attained by the proposed system, when compared to a corresponding benchmarker scheme having the same Pilot overhead but using the PSAM technique.
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Pilot Symbol assisted coding
Electronics Letters, 2009Co-Authors: N. Bonello, Sheng Chen, Lajos HanzoAbstract:Proposed is a novel technique, hereby referred to as Pilot Symbol assisted coding (PSAC), where a predetermined fraction of binary Pilot Symbols is interspersed with the channel-coded bits at the channel coding stage, instead of multiplexing the Pilots with the data Symbols at the modulation stage, as in classic Pilot Symbol assisted modulation (PSAM). It is demonstrated that the PSAC succeeds in gleaning more benefits from the Pilot overhead investment, than just simply the capability of channel estimation such as in the PSAM technique.
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On the Design of Pilot Symbol Assisted Codes
2009 IEEE 70th Vehicular Technology Conference Fall, 2009Co-Authors: N. Bonello, Sheng Chen, Lajos HanzoAbstract:We propose a novel technique, hereby referred to as Pilot Symbol assisted coding (PSAC), where a predetermined fraction of binary Pilot Symbols is interspersed with the channel-coded bits at the channel coding stage, instead of multiplexing the Pilots with the data Symbols at the modulation stage, as in classic Pilot Symbol assisted modulation (PSAM). We will subsequently demonstrate that the PSACaided scheme succeeds in gleaning more beneficial knowledge from the inserted Pilots, because the Pilot bits are not only useful for estimating the channel at the receiver, but they are also beneficial in terms of significantly reducing the computational complexity of the channel decoder. Our results suggest that in the specific application example considered the PSAC-aided scheme requires up to 45% fewer messagepassing updates per decoded bit than the corresponding channel coded PSAM benchmarker scheme.
Michal Simko - One of the best experts on this subject based on the ideXlab platform.
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bit error probability for Pilot Symbol aided ofdm channel estimation in doubly selective channels
International ITG Workshop on Smart Antennas, 2014Co-Authors: Ronald Nissel, Michal Simko, Martin Lerch, Markus RuppAbstract:In this paper, we derive a closed-form expression for the Bit Error Probability (BEP) of an orthogonal frequencydivision multiplexing system that utilizes Pilot-Symbol-aided channel estimation. We assume Rayleigh fading, additive white Gaussian noise, and that the interpolation is linear but otherwise completely arbitrary. It is shown that the minimum mean squared error interpolation also minimizes the BEP. For a Signal-to-Interference Ratio (SIR) smaller than the signal-to-noise ratio, simulations confirm our analytical results. However, for higher SIR they exhibit differences because the inter-carrier interference is not normally distributed, violating our assumptions.
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adaptive Pilot Symbol patterns for mimo ofdm systems
IEEE Transactions on Wireless Communications, 2013Co-Authors: Michal Simko, Paulo S R Diniz, Qi Wang, Markus RuppAbstract:Recent standards for cellular transmission systems offer a lot of flexibility, such as the choice of transmission modes, modulation alphabets, coding rates, and precoding matrices. Despite this trend, Pilot-Symbol patterns in today's standards remain fixed, although such an approach is suboptimal. In this paper, we show how to design optimal Pilot-Symbol patterns by maximizing an upper bound of a constrained capacity that takes channel estimation errors and Inter Carrier Interference into account. Furthermore, we propose adaptive Pilot-Symbol patterns that follow changing channel statistics. As a proof of concept, we present throughput simulation results of two competitive systems, a transmission system compliant with the Long Term Evolution (LTE)-standard and an improved system utilizing the proposed adaptive Pilot patterns. The transmission system utilizing adaptive Pilot patterns outperforms an LTE-standard compliant system in all considered scenarios. The throughput gain for a single input single output system ranges between 3% and 80%. For a 4 × 4 transmission system, the performance gain is significantly higher and can reach up to 850% compared to a conventional LTE system.
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WCNC - New insights in optimal Pilot Symbol patterns for OFDM systems
2013 IEEE Wireless Communications and Networking Conference (WCNC), 2013Co-Authors: Michal Simko, Paulo S R Diniz, Qi Wang, Markus RuppAbstract:Nowadays, most wireless communication systems utilize coherent detection which implies the necessity of multiplexing reference Symbols between data-Symbols for the purpose of channel estimation. In Long Term Evolution (LTE), these reference Symbols can consume up to 14.2% of the total bandwidth. In this work, we search for an optimal Pilot-Symbol pattern design using a post-equalization Signal to Interference and Noise Ratio (SINR) framework. We show how close to optimally choose the distance between adjacent Pilot-Symbols and how to distribute the available power between Pilot and data Symbol at the same time. We confirm the performance of our analytical solution by means of simulation. Compared to a system with a fixed distance between Pilot-Symbol and unit power distribution, the proposed system configuration yields a gain of around 30% in terms of capacity.
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optimal Pilot Symbol power allocation in lte
Vehicular Technology Conference, 2011Co-Authors: Michal Simko, Qi Wang, Stefan Pendl, Stefan Schwarz, Josep Colom Ikuno, Markus RuppAbstract:The UMTS Long Term Evolution (LTE) allows the Pilot Symbol power to be adjusted with respect to that of the data Symbols. Such power increase at the Pilot Symbols results in a more accurate channel estimate, but in turn reduces the amount of power available for the data transmission. In this paper, we derive optimal Pilot Symbol power allocation based on maximization of the post-equalization Signal to Interference and Noise Ratio (SINR) under imperfect channel knowledge. Simulation validates our analytical mode for optimal Pilot Symbol power allocation.
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VTC Fall - Optimal Pilot Symbol Power Allocation in LTE
2011 IEEE Vehicular Technology Conference (VTC Fall), 2011Co-Authors: Michal Simko, Qi Wang, Stefan Pendl, Stefan Schwarz, Josep Colom Ikuno, Markus RuppAbstract:The UMTS Long Term Evolution (LTE) allows the Pilot Symbol power to be adjusted with respect to that of the data Symbols. Such power increase at the Pilot Symbols results in a more accurate channel estimate, but in turn reduces the amount of power available for the data transmission. In this paper, we derive optimal Pilot Symbol power allocation based on maximization of the post-equalization Signal to Interference and Noise Ratio (SINR) under imperfect channel knowledge. Simulation validates our analytical mode for optimal Pilot Symbol power allocation.
N. Bonello - One of the best experts on this subject based on the ideXlab platform.
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generalized mimo transmit preprocessing using Pilot Symbol assisted rateless codes
Vehicular Technology Conference, 2010Co-Authors: N. Bonello, Sheng Chen, Du Yang, Lajos HanzoAbstract:In this paper, we propose a generalized multiple-input multiple-output (MIMO) transmit preprocessing system, where both the channel coding and the linear MIMO transmit precoding components exploit the knowledge of the channel. Moreover, we also propose a novel technique, hereby referred to as Pilot Symbol assisted rateless (PSAR) coding, where a predetermined fraction of binary Pilot Symbols is interspersed with the channel-coded bits at the channel coding stage, instead of multiplexing the Pilots with the data Symbols at the modulation stage, as in classic Pilot Symbol assisted modulation (PSAM). We will subsequently demonstrate that the PSAR code-aided transmit preprocessing scheme succeeds in gleaning more beneficial knowledge from the inserted Pilots, because the Pilot bits are not only useful for estimating the channel at the receiver, but they are also beneficial in terms of significantly reducing the computational complexity of the rateless channel decoder.
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VTC Spring - Generalized MIMO Transmit Preprocessing Using Pilot Symbol Assisted Rateless Codes
2010 IEEE 71st Vehicular Technology Conference, 2010Co-Authors: N. Bonello, Sheng Chen, Du Yang, Lajos HanzoAbstract:In this paper, we propose a generalized multiple-input multiple-output (MIMO) transmit preprocessing system, where both the channel coding and the linear MIMO transmit precoding components exploit the knowledge of the channel. Moreover, we also propose a novel technique, hereby referred to as Pilot Symbol assisted rateless (PSAR) coding, where a predetermined fraction of binary Pilot Symbols is interspersed with the channel-coded bits at the channel coding stage, instead of multiplexing the Pilots with the data Symbols at the modulation stage, as in classic Pilot Symbol assisted modulation (PSAM). We will subsequently demonstrate that the PSAR code-aided transmit preprocessing scheme succeeds in gleaning more beneficial knowledge from the inserted Pilots, because the Pilot bits are not only useful for estimating the channel at the receiver, but they are also beneficial in terms of significantly reducing the computational complexity of the rateless channel decoder.
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Generalized MIMO transmit preprocessing using Pilot Symbol assisted rateless codes
IEEE Transactions on Wireless Communications, 2010Co-Authors: N. Bonello, Sheng Chen, Du Yang, Lajos HanzoAbstract:In this paper, we propose a generalized multipleinput multiple-output (MIMO) transmit preprocessing system, where both the channel coding and the linear MIMO transmit precoding components exploit the knowledge of the channel. This was achieved by exploiting the inherently flexible nature of a specific family of rateless codes that are capable of modifying their code-rate as well as their degree distribution based on the channel state information (CSI), in an attempt to adapt to the time-varying nature of the channel. Moreover, we also propose a novel technique, hereby referred to as Pilot Symbol assisted rateless (PSAR) coding, where a predetermined fraction of binary Pilot Symbols is interspersed with the channel-coded bits at the channel coding stage, instead of multiplexing the Pilots with the data Symbols at the modulation stage, as in classic Pilot Symbol assisted modulation (PSAM). We will subsequently demonstrate that the PSAR code-aided transmit preprocessing scheme succeeds in gleaning more beneficial knowledge from the inserted Pilots, because the Pilot bits are not only useful for estimating the channel at the receiver, but they are also beneficial in terms of significantly reducing the computational complexity of the rateless channel decoder. Our results suggest that more than a 30% reduction in the decoder's computational complexity can be attained by the proposed system, when compared to a corresponding benchmarker scheme having the same Pilot overhead but using the PSAM technique.
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Pilot Symbol assisted coding
Electronics Letters, 2009Co-Authors: N. Bonello, Sheng Chen, Lajos HanzoAbstract:Proposed is a novel technique, hereby referred to as Pilot Symbol assisted coding (PSAC), where a predetermined fraction of binary Pilot Symbols is interspersed with the channel-coded bits at the channel coding stage, instead of multiplexing the Pilots with the data Symbols at the modulation stage, as in classic Pilot Symbol assisted modulation (PSAM). It is demonstrated that the PSAC succeeds in gleaning more benefits from the Pilot overhead investment, than just simply the capability of channel estimation such as in the PSAM technique.
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On the Design of Pilot Symbol Assisted Codes
2009 IEEE 70th Vehicular Technology Conference Fall, 2009Co-Authors: N. Bonello, Sheng Chen, Lajos HanzoAbstract:We propose a novel technique, hereby referred to as Pilot Symbol assisted coding (PSAC), where a predetermined fraction of binary Pilot Symbols is interspersed with the channel-coded bits at the channel coding stage, instead of multiplexing the Pilots with the data Symbols at the modulation stage, as in classic Pilot Symbol assisted modulation (PSAM). We will subsequently demonstrate that the PSACaided scheme succeeds in gleaning more beneficial knowledge from the inserted Pilots, because the Pilot bits are not only useful for estimating the channel at the receiver, but they are also beneficial in terms of significantly reducing the computational complexity of the channel decoder. Our results suggest that in the specific application example considered the PSAC-aided scheme requires up to 45% fewer messagepassing updates per decoded bit than the corresponding channel coded PSAM benchmarker scheme.
J K Cavers - One of the best experts on this subject based on the ideXlab platform.
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Pilot Symbol assisted modulation and differential detection in fading and delay spread
IEEE Transactions on Communications, 1995Co-Authors: J K CaversAbstract:Pilot Symbol assisted modulation (PSAM) has previously been shown to give good performance in flat fading, noise and cochannel interference. The present paper analyzes its performance in ISI due to frequency selective fading, and provides a similar analysis of differential detection for comparison. The paper also introduces a method for performing the formidable average over transmitted data patterns simply, and with an analytical result, PSAM is shown to be sensitive to RMS delay spread, though it always gives better performance than differential detection. >
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Cochannel interference and Pilot Symbol assisted modulation
IEEE Transactions on Vehicular Technology, 1993Co-Authors: J K Cavers, J. VaraldiAbstract:Pilot Symbol assisted modulation (PSAM) has been shown to give good performance in Rayleigh fading and additive noise. In cellular systems, though, it is cochannel interference, more than noise, that limits the system. The paper is the first analytical investigation of the performance of PSAM in fading, interference, and noise. The investigation yields both an exact solution and an accurate but much more computationally efficient approximation. >
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a comparison of Pilot tone and Pilot Symbol techniques for digital mobile communication
Global Communications Conference, 1992Co-Authors: J K Cavers, M. LiaoAbstract:Both Pilot tone and Pilot Symbol assisted modulation (PTAM and PSAM, respectively) have been proposed for improving transmission performance over flat fading channels. It is shown that there are important practical advantages which favor the Pilot Symbol technique. PTAM is represented by TTIB (transparent tone-in-band), its most successful version. Bit error rate (BER) performance, the linearization effort required, spectral occupancy, delay, and complexity are considered. On all points but delay, PSAM is superior to PTAM. The strongest contrast is in BER performance, where, for any power amplifier, TTIB is typically 4 dB poorer than PSAM. >
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an analysis of Pilot Symbol assisted modulation for rayleigh fading channels mobile radio
IEEE Transactions on Vehicular Technology, 1991Co-Authors: J K CaversAbstract:The author presents Pilot-Symbol-assisted modulation (PSAM) on a solid analytical basis, a feature missing from previous work. Closed-form expressions are presented for the bit error rate (BER) in binary-phase-shift-keying (BPSK) and in quadrature-phase-shift-keying (QPSK), for a tight upper bound on the Symbol error rate in 16 quadrature-amplitude-modulation (16-QAM), and for the optimized receiver coefficients. The error rates obtained are lower than for differential detection for any combination of signal-to-noise ratio (SNR) and Doppler spread, and the performance is within 1 dB of a perfect reference system under slow-fading conditions and within 3 dB when the Doppler spread is 5% of the Symbol rate. >
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Pilot Symbol assisted modulation in fading and delay spread
IEEE 43rd Vehicular Technology Conference, 1Co-Authors: J K CaversAbstract:The performance of Pilot Symbol assisted modulation (PSAM) is analyzed in interSymbol interference (ISI) due to frequency selective fading. PSAM is shown to be sensitive to RMS delay spread, though it always gives better performance than differential detection.
