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Narayan B Mandayam  One of the best experts on this subject based on the ideXlab platform.

uplink linear receivers for multi cell multiuser mimo with pilot contamination large System Analysis
2014CoAuthors: Narayanan Krishnan, Roy D Yates, Narayan B MandayamAbstract:Base stations with a large number of transmit antennas can potentially serve a large number of users at high rates. However, the receiver processing in the uplink relies on channel estimates, which are known to suffer from pilot interference. In this paper, making use of the similarity of the uplink received signal in CDMA with that of a multicell multiantenna System, we perform a large System Analysis when the receiver employs an MMSE filter with a pilot contaminated estimate. We assume a Rayleigh fading channel with different received powers from users. We find the asymptotic signal to interference plus noise ratio (SINR) as the number of antennas and number of users per base station grow larger while maintaining a fixed ratio. Through the SINR expression we explore the scenario where the number of users being served are comparable to the number of antennas at the base station. The SINR explicitly captures the effect of pilot contamination and is found to be the same as that employing a matched filter with a pilot contaminated estimate. We also find the exact expression for the interference suppression obtained using an MMSE filter, which is an important factor when there are a significant number of users in the System as compared to the number of antennas. In a typical set up, in terms of the five percentile SINR, the MMSE filter is shown to provide significant gains over matched filtering and is within 5 dB of MMSE filter with perfect channel estimate. Simulation results for achievable rates are close to large System limits for even a 10antenna base station with 3 or more users per cell.

uplink linear receivers for multi cell multiuser mimo with pilot contamination large System Analysis
2013CoAuthors: Narayanan Krishnan, Roy D Yates, Narayan B MandayamAbstract:Base stations with a large number of transmit antennas have the potential to serve a large number of users at high rates. However, the receiver processing in the uplink relies on channel estimates which are known to suffer from pilot interference. In this work, making use of the similarity of the uplink received signal in CDMA with that of a multicell multiantenna System, we perform a large System Analysis when the receiver employs an MMSE filter with a pilot contaminated estimate. We assume a Rayleigh fading channel with different received powers from users. We find the asymptotic Signal to Interference plus Noise Ratio (SINR) as the number of antennas and number of users per base station grow large while maintaining a fixed ratio. Through the SINR expression we explore the scenario where the number of users being served are comparable to the number of antennas at the base station. The SINR explicitly captures the effect of pilot contamination and is found to be the same as that employing a matched filter with a pilot contaminated estimate. We also find the exact expression for the interference suppression obtained using an MMSE filter which is an important factor when there are significant number of users in the System as compared to the number of antennas. In a typical set up, in terms of the five percentile SINR, the MMSE filter is shown to provide significant gains over matched filtering and is within 5 dB of MMSE filter with perfect channel estimate. Simulation results for achievable rates are close to large System limits for even a 10antenna base station with 3 or more users per cell.

cellular Systems with many antennas large System Analysis under pilot contamination
2012CoAuthors: Narayanan Krishnan, Roy D Yates, Narayan B MandayamAbstract:Base stations with a large number of transmit antennas have the potential to serve a large number of users simultaneously at higher rates. They also promise a lower power consumption due to coherent combining at the receiver. However, the receiver processing in the uplink relies on the channel estimates which are known to suffer from pilot interference. In this work, we perform an uplink large System Analysis of multicell multiantenna System when the receiver employs a matched filtering with a pilot contaminated estimate. We find the asymptotic Signal to Interference plus Noise Ratio (SINR) as the number of antennas and number of users per base station grow large while maintaining a fixed ratio. To do this, we make use of the similarity of the uplink received signal in a multiantenna System to the representation of the received signal in CDMA Systems. The asymptotic SINR expression explicitly captures the effect of pilot contamination and that of interference averaging. This also explains the SINR performance of receiver processing schemes at different regimes such as instances when the number of antennas are comparable to number of users as well as when antennas exceed greatly the number of users. Finally, we also propose that the adaptive MMSE symbol detection scheme, which does not require the explicit channel knowledge, can be employed for cellular Systems with large number of antennas.
Narayanan Krishnan  One of the best experts on this subject based on the ideXlab platform.

uplink linear receivers for multi cell multiuser mimo with pilot contamination large System Analysis
2014CoAuthors: Narayanan Krishnan, Roy D Yates, Narayan B MandayamAbstract:Base stations with a large number of transmit antennas can potentially serve a large number of users at high rates. However, the receiver processing in the uplink relies on channel estimates, which are known to suffer from pilot interference. In this paper, making use of the similarity of the uplink received signal in CDMA with that of a multicell multiantenna System, we perform a large System Analysis when the receiver employs an MMSE filter with a pilot contaminated estimate. We assume a Rayleigh fading channel with different received powers from users. We find the asymptotic signal to interference plus noise ratio (SINR) as the number of antennas and number of users per base station grow larger while maintaining a fixed ratio. Through the SINR expression we explore the scenario where the number of users being served are comparable to the number of antennas at the base station. The SINR explicitly captures the effect of pilot contamination and is found to be the same as that employing a matched filter with a pilot contaminated estimate. We also find the exact expression for the interference suppression obtained using an MMSE filter, which is an important factor when there are a significant number of users in the System as compared to the number of antennas. In a typical set up, in terms of the five percentile SINR, the MMSE filter is shown to provide significant gains over matched filtering and is within 5 dB of MMSE filter with perfect channel estimate. Simulation results for achievable rates are close to large System limits for even a 10antenna base station with 3 or more users per cell.

uplink linear receivers for multi cell multiuser mimo with pilot contamination large System Analysis
2013CoAuthors: Narayanan Krishnan, Roy D Yates, Narayan B MandayamAbstract:Base stations with a large number of transmit antennas have the potential to serve a large number of users at high rates. However, the receiver processing in the uplink relies on channel estimates which are known to suffer from pilot interference. In this work, making use of the similarity of the uplink received signal in CDMA with that of a multicell multiantenna System, we perform a large System Analysis when the receiver employs an MMSE filter with a pilot contaminated estimate. We assume a Rayleigh fading channel with different received powers from users. We find the asymptotic Signal to Interference plus Noise Ratio (SINR) as the number of antennas and number of users per base station grow large while maintaining a fixed ratio. Through the SINR expression we explore the scenario where the number of users being served are comparable to the number of antennas at the base station. The SINR explicitly captures the effect of pilot contamination and is found to be the same as that employing a matched filter with a pilot contaminated estimate. We also find the exact expression for the interference suppression obtained using an MMSE filter which is an important factor when there are significant number of users in the System as compared to the number of antennas. In a typical set up, in terms of the five percentile SINR, the MMSE filter is shown to provide significant gains over matched filtering and is within 5 dB of MMSE filter with perfect channel estimate. Simulation results for achievable rates are close to large System limits for even a 10antenna base station with 3 or more users per cell.

cellular Systems with many antennas large System Analysis under pilot contamination
2012CoAuthors: Narayanan Krishnan, Roy D Yates, Narayan B MandayamAbstract:Base stations with a large number of transmit antennas have the potential to serve a large number of users simultaneously at higher rates. They also promise a lower power consumption due to coherent combining at the receiver. However, the receiver processing in the uplink relies on the channel estimates which are known to suffer from pilot interference. In this work, we perform an uplink large System Analysis of multicell multiantenna System when the receiver employs a matched filtering with a pilot contaminated estimate. We find the asymptotic Signal to Interference plus Noise Ratio (SINR) as the number of antennas and number of users per base station grow large while maintaining a fixed ratio. To do this, we make use of the similarity of the uplink received signal in a multiantenna System to the representation of the received signal in CDMA Systems. The asymptotic SINR expression explicitly captures the effect of pilot contamination and that of interference averaging. This also explains the SINR performance of receiver processing schemes at different regimes such as instances when the number of antennas are comparable to number of users as well as when antennas exceed greatly the number of users. Finally, we also propose that the adaptive MMSE symbol detection scheme, which does not require the explicit channel knowledge, can be employed for cellular Systems with large number of antennas.
Federico Milano  One of the best experts on this subject based on the ideXlab platform.

a python based software tool for power System Analysis
2013CoAuthors: Federico MilanoAbstract:This paper presents a power System Analysis tool, called DOME, entirely based on Python scripting language as well as on public domain efficient C and Fortran libraries. The objects of the paper are twofold. First, the paper discusses the features that makes the Python language an adequate tool for research, massive numerical simulations and education. Then the paper describes the architecture of the developed software tool and provides a variety of examples to show the advanced features and the performance of the developed tool.

experience with psat power System Analysis toolbox as free and open source software for power System education and research
2010CoAuthors: Luigi Vanfretti, Federico MilanoAbstract:This paper describes the assessment of a free and opensource software tool for power System Analysis and modeling, namely Power System Analysis Toolbox (PSAT). PSAT is currently used in several universities for undergraduate and graduate courses and research. Several applications of PSAT as an educational and research tool are discussed here. The paper also describes the PSAT Web forum, which provides support to students and researchers all around the world. Finally, the paper presents and discusses the results of a survey on PSAT fi lled out by the members of the PSAT forum and PSAT users.

an open source power System Analysis toolbox
2006CoAuthors: Federico MilanoAbstract:Summary form only given. This paper describes the power System Analysis toolbox (PSAT), an open source Matlab and GNU/Octavebased software package for Analysis and design of small to medium size electric power Systems. PSAT includes power flow, continuation power flow, optimal power flow, small signal stability Analysis and time domain simulation as well as several static and dynamic models, including nonconventional loads, synchronous and synchronous machines, regulators and FACTS. PSAT is also provided with a complete set of userfriendly graphical interfaces and a Simulinkbased editor of oneline network diagrams. Basic features, algorithms and a variety of case studies are presented in this paper to illustrate the capabilities of the presented tool and its suitability for educational and research purposes.

an open source power System Analysis toolbox
2005CoAuthors: Federico MilanoAbstract:This paper describes the Power System Analysis Toolbox (PSAT), an open source Matlab and GNU/Octavebased software package for Analysis and design of small to medium size electric power Systems. PSAT includes power flow, continuation power flow, optimal power flow, smallsignal stability Analysis, and timedomain simulation, as well as several static and dynamic models, including nonconventional loads, synchronous and asynchronous machines, regulators, and FACTS. PSAT is also provided with a complete set of userfriendly graphical interfaces and a Simulinkbased editor of oneline network diagrams. Basic features, algorithms, and a variety of case studies are presented in this paper to illustrate the capabilities of the presented tool and its suitability for educational and research purposes.
Roy D Yates  One of the best experts on this subject based on the ideXlab platform.

uplink linear receivers for multi cell multiuser mimo with pilot contamination large System Analysis
2014CoAuthors: Narayanan Krishnan, Roy D Yates, Narayan B MandayamAbstract:Base stations with a large number of transmit antennas can potentially serve a large number of users at high rates. However, the receiver processing in the uplink relies on channel estimates, which are known to suffer from pilot interference. In this paper, making use of the similarity of the uplink received signal in CDMA with that of a multicell multiantenna System, we perform a large System Analysis when the receiver employs an MMSE filter with a pilot contaminated estimate. We assume a Rayleigh fading channel with different received powers from users. We find the asymptotic signal to interference plus noise ratio (SINR) as the number of antennas and number of users per base station grow larger while maintaining a fixed ratio. Through the SINR expression we explore the scenario where the number of users being served are comparable to the number of antennas at the base station. The SINR explicitly captures the effect of pilot contamination and is found to be the same as that employing a matched filter with a pilot contaminated estimate. We also find the exact expression for the interference suppression obtained using an MMSE filter, which is an important factor when there are a significant number of users in the System as compared to the number of antennas. In a typical set up, in terms of the five percentile SINR, the MMSE filter is shown to provide significant gains over matched filtering and is within 5 dB of MMSE filter with perfect channel estimate. Simulation results for achievable rates are close to large System limits for even a 10antenna base station with 3 or more users per cell.

uplink linear receivers for multi cell multiuser mimo with pilot contamination large System Analysis
2013CoAuthors: Narayanan Krishnan, Roy D Yates, Narayan B MandayamAbstract:Base stations with a large number of transmit antennas have the potential to serve a large number of users at high rates. However, the receiver processing in the uplink relies on channel estimates which are known to suffer from pilot interference. In this work, making use of the similarity of the uplink received signal in CDMA with that of a multicell multiantenna System, we perform a large System Analysis when the receiver employs an MMSE filter with a pilot contaminated estimate. We assume a Rayleigh fading channel with different received powers from users. We find the asymptotic Signal to Interference plus Noise Ratio (SINR) as the number of antennas and number of users per base station grow large while maintaining a fixed ratio. Through the SINR expression we explore the scenario where the number of users being served are comparable to the number of antennas at the base station. The SINR explicitly captures the effect of pilot contamination and is found to be the same as that employing a matched filter with a pilot contaminated estimate. We also find the exact expression for the interference suppression obtained using an MMSE filter which is an important factor when there are significant number of users in the System as compared to the number of antennas. In a typical set up, in terms of the five percentile SINR, the MMSE filter is shown to provide significant gains over matched filtering and is within 5 dB of MMSE filter with perfect channel estimate. Simulation results for achievable rates are close to large System limits for even a 10antenna base station with 3 or more users per cell.

cellular Systems with many antennas large System Analysis under pilot contamination
2012CoAuthors: Narayanan Krishnan, Roy D Yates, Narayan B MandayamAbstract:Base stations with a large number of transmit antennas have the potential to serve a large number of users simultaneously at higher rates. They also promise a lower power consumption due to coherent combining at the receiver. However, the receiver processing in the uplink relies on the channel estimates which are known to suffer from pilot interference. In this work, we perform an uplink large System Analysis of multicell multiantenna System when the receiver employs a matched filtering with a pilot contaminated estimate. We find the asymptotic Signal to Interference plus Noise Ratio (SINR) as the number of antennas and number of users per base station grow large while maintaining a fixed ratio. To do this, we make use of the similarity of the uplink received signal in a multiantenna System to the representation of the received signal in CDMA Systems. The asymptotic SINR expression explicitly captures the effect of pilot contamination and that of interference averaging. This also explains the SINR performance of receiver processing schemes at different regimes such as instances when the number of antennas are comparable to number of users as well as when antennas exceed greatly the number of users. Finally, we also propose that the adaptive MMSE symbol detection scheme, which does not require the explicit channel knowledge, can be employed for cellular Systems with large number of antennas.
S A Khaparde  One of the best experts on this subject based on the ideXlab platform.

design of generic direct sparse linear System solver in c for power System Analysis
2001CoAuthors: S Pandit, S A Soman, S A KhapardeAbstract:This article presents the design of the generic linear System solver (LSS) for a class of large sparse symmetric matrices over real and complex numbers. These matrices correspond to one of the following: (1) symmetric positive definite (SPD) matrices, (2) complex Hermitian matrices, or (3) complex matrices with SPD real and imaginary matrices. Such matrices arise in various power System Analysis applications like load flow Analysis and short circuit Analysis. A template facility of C++ is used to write a generic program on float, double, and complex data types. The design of the algorithm guarantees numerical stability and efficient sparsity implementation. A reusable class SET is defined to cater to graph theoretic computations. LSS problems with matrices up to 20,000 nodes have been tested. Another feature of the proposed LSS is the implementation of associative array, which allows subscripting an array with character strings, such as bus names. This helps in making the four power System Analysis software user friendly. The proposed LSS reflects an important development towards a truly objectoriented four power System Analysis software.