Pub Date : 2010-04-29DOI: 10.1109/WSA.2010.5456382
J. Costa, F. Roemer, M. Weis, M. Haardt
R-dimensional parameter estimation problems are common in a variety of signal processing applications. In order to solve such problems, we propose a robust multidimensional model order selection scheme and a robust multidimensional parameter estimation scheme using the closed-form PARAFAC algorithm, which is a recently proposed way to compute the PARAFAC decomposition based on several simultaneous diagonalizations. In general, R-dimensional (R-D) model order selection (MOS) techniques, e.g., the R-D Exponential Fitting Test (R-D EFT), are designed for multidimensional data by taking into account its multidimensional structure. However, the R-D MOS techniques assume that the data is contaminated by white Gaussian noise. To deal with colored noise, we propose the closed-form PARAFAC based model order selection (CFP-MOS) technique based on multiple estimates of the factor matrices provided as an intermediate step by the closed-form PARAFAC algorithm. Additionally, we propose the closed-form PARAFAC based parameter estimator (CFP-PE), which can be applied to extract spatial frequencies in case of arbitrary array geometries.
{"title":"Robust R-D parameter estimation via closed-form PARAFAC","authors":"J. Costa, F. Roemer, M. Weis, M. Haardt","doi":"10.1109/WSA.2010.5456382","DOIUrl":"https://doi.org/10.1109/WSA.2010.5456382","url":null,"abstract":"R-dimensional parameter estimation problems are common in a variety of signal processing applications. In order to solve such problems, we propose a robust multidimensional model order selection scheme and a robust multidimensional parameter estimation scheme using the closed-form PARAFAC algorithm, which is a recently proposed way to compute the PARAFAC decomposition based on several simultaneous diagonalizations. In general, R-dimensional (R-D) model order selection (MOS) techniques, e.g., the R-D Exponential Fitting Test (R-D EFT), are designed for multidimensional data by taking into account its multidimensional structure. However, the R-D MOS techniques assume that the data is contaminated by white Gaussian noise. To deal with colored noise, we propose the closed-form PARAFAC based model order selection (CFP-MOS) technique based on multiple estimates of the factor matrices provided as an intermediate step by the closed-form PARAFAC algorithm. Additionally, we propose the closed-form PARAFAC based parameter estimator (CFP-PE), which can be applied to extract spatial frequencies in case of arbitrary array geometries.","PeriodicalId":311394,"journal":{"name":"2010 International ITG Workshop on Smart Antennas (WSA)","volume":"82 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129377074","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-04-29DOI: 10.1109/WSA.2010.5456437
J. Giese, M. A. Amin
Coordinated Multipoint (CoMP) transmission techniques have been considered as tools to improve cell-edge and average data throughput for LTE-Advanced. First investigations of CoMP techniques in homogeneous hexagonal macro layouts have shown that interference coordination needs to involve dominant interferers to allow significant gain. Therefore, in the present paper the application of CoMP in a heterogeneous network is considered where a planned macro deployment coexists with randomly placed femtocells resulting in a scenario where dominant interference can potentially be mitigated more effectively. The impacts of a heterogeneous layout on the interference characteristics in the downlink are evaluated by simulation and an assessment of gains achieved through coordination is provided.
{"title":"Performance upper bounds for coordinated beam selection in LTE-Advanced","authors":"J. Giese, M. A. Amin","doi":"10.1109/WSA.2010.5456437","DOIUrl":"https://doi.org/10.1109/WSA.2010.5456437","url":null,"abstract":"Coordinated Multipoint (CoMP) transmission techniques have been considered as tools to improve cell-edge and average data throughput for LTE-Advanced. First investigations of CoMP techniques in homogeneous hexagonal macro layouts have shown that interference coordination needs to involve dominant interferers to allow significant gain. Therefore, in the present paper the application of CoMP in a heterogeneous network is considered where a planned macro deployment coexists with randomly placed femtocells resulting in a scenario where dominant interference can potentially be mitigated more effectively. The impacts of a heterogeneous layout on the interference characteristics in the downlink are evaluated by simulation and an assessment of gains achieved through coordination is provided.","PeriodicalId":311394,"journal":{"name":"2010 International ITG Workshop on Smart Antennas (WSA)","volume":"182 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115580413","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-04-29DOI: 10.1109/WSA.2010.5456391
K. Anwar, T. Matsumoto
This paper proposes a structure that combines iterative equalization and turbo decoding, denoted as spatial turbo coding (STC), for single carrier signaling to achieve near capacity performance in multipath-rich fading channels. Instead of multiplexing the encoded bits in the time domain as in the standard turbo codes, the proposed STC transmits coded bits in the space domain by employing multiple-input multiple-output (MIMO) transceiver to exploit space diversity, path diversity and coding gains through the decoding branches at the receiver. The considered MIMO detector is a MIMO frequency domain soft-cancelation and minimum mean square error equalizer (FD/SC-MMSE). Extrinsic Information Transfer (EXIT) chart analysis confirms that bit-error-rate (BER) pinch-off is achieved in 64-path Rayleigh fading channels with equal average path gains power which is just by about 1dB away from the static channel capacity/dimension of 2×2 MIMO systems.
{"title":"MIMO spatial turbo coding with iterative equalization","authors":"K. Anwar, T. Matsumoto","doi":"10.1109/WSA.2010.5456391","DOIUrl":"https://doi.org/10.1109/WSA.2010.5456391","url":null,"abstract":"This paper proposes a structure that combines iterative equalization and turbo decoding, denoted as spatial turbo coding (STC), for single carrier signaling to achieve near capacity performance in multipath-rich fading channels. Instead of multiplexing the encoded bits in the time domain as in the standard turbo codes, the proposed STC transmits coded bits in the space domain by employing multiple-input multiple-output (MIMO) transceiver to exploit space diversity, path diversity and coding gains through the decoding branches at the receiver. The considered MIMO detector is a MIMO frequency domain soft-cancelation and minimum mean square error equalizer (FD/SC-MMSE). Extrinsic Information Transfer (EXIT) chart analysis confirms that bit-error-rate (BER) pinch-off is achieved in 64-path Rayleigh fading channels with equal average path gains power which is just by about 1dB away from the static channel capacity/dimension of 2×2 MIMO systems.","PeriodicalId":311394,"journal":{"name":"2010 International ITG Workshop on Smart Antennas (WSA)","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126633711","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-04-29DOI: 10.1109/WSA.2010.5456460
Yidong Lang, D. Wübben, K. Kammeyer
In this paper we consider a two-way relaying system with two sources A, B and one relay R, where the two sources desire to exchange information through the relay. The transmission consists of two states: multiple access (MAC) stage, where A and B transmit the channel-coded signals to R simultaneously, and broadcast (BC) stage, where R transmits towards both A and B. One critical process at R is to decode the superimposed signal from A and B in such a way that A and B could decode the information from each other reliably at the BC stage. Instead of decoding the individual information belonging to A and B separately, R aims to decode the superimposed signal to the network-coded combination of the two source information, i.e., the binary XOR of the two source information. We refer this decoding process as the joint channel decoding and physical network encoding (JCNC). In this paper, a novel iterative decoding algorithm is presented for the physical network coding scheme, which is applicable to any linear channel code, e.g. Low-Density Parity-Check (LDPC) code. Furthermore, the two-way relaying scheme is extended to distributed multiple input multiple output (MIMO) multi-hop networks. Based on an antenna selection criterion within each virtual antenna array (VAA), the end-to-end (e2e) BER of the multi-hop system can be further reduced. Simulation results show that the proposed scheme outperforms other recently proposed network coding schemes with slightly increased complexity.
{"title":"An improved physical layer network coding scheme for two-way relay systems","authors":"Yidong Lang, D. Wübben, K. Kammeyer","doi":"10.1109/WSA.2010.5456460","DOIUrl":"https://doi.org/10.1109/WSA.2010.5456460","url":null,"abstract":"In this paper we consider a two-way relaying system with two sources A, B and one relay R, where the two sources desire to exchange information through the relay. The transmission consists of two states: multiple access (MAC) stage, where A and B transmit the channel-coded signals to R simultaneously, and broadcast (BC) stage, where R transmits towards both A and B. One critical process at R is to decode the superimposed signal from A and B in such a way that A and B could decode the information from each other reliably at the BC stage. Instead of decoding the individual information belonging to A and B separately, R aims to decode the superimposed signal to the network-coded combination of the two source information, i.e., the binary XOR of the two source information. We refer this decoding process as the joint channel decoding and physical network encoding (JCNC). In this paper, a novel iterative decoding algorithm is presented for the physical network coding scheme, which is applicable to any linear channel code, e.g. Low-Density Parity-Check (LDPC) code. Furthermore, the two-way relaying scheme is extended to distributed multiple input multiple output (MIMO) multi-hop networks. Based on an antenna selection criterion within each virtual antenna array (VAA), the end-to-end (e2e) BER of the multi-hop system can be further reduced. Simulation results show that the proposed scheme outperforms other recently proposed network coding schemes with slightly increased complexity.","PeriodicalId":311394,"journal":{"name":"2010 International ITG Workshop on Smart Antennas (WSA)","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126187420","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-04-29DOI: 10.1109/WSA.2010.5456395
U. L. Dang, Michael A. Ruder, W. Gerstacker, R. Schober
We consider transmit beamforming algorithms for single-carrier frequency-division multiple access (SC-FDMA) transmission over frequency-selective multiple-input multiple-output (MIMO) channels. The beamforming filters are designed for optimum performance of MIMO minimum mean-squared error decision-feedback equalization (MMSE-DFE). It turns out that eigenbeamforming diagonalizing the overall channel is optimum, and in addition an optimum power allocation has to be performed which is similar in spirit to classical results for the optimum continuous-time transmit filter for linear modulation formats obtained by Yang and Roy. Simulation results indicate that the proposed solution is beneficial for the block error rate performance of an SC-FDMA transmission scheme with strong channel coding and error-free decisions in the feedback path of MMSE-DFE, which can be guaranteed e.g. by equivalent Tomlinson-Harashima precoding at the transmitter side.
{"title":"Beamforming for SC-FDMA transmission over MIMO ISI channels with decision-feedback equalization","authors":"U. L. Dang, Michael A. Ruder, W. Gerstacker, R. Schober","doi":"10.1109/WSA.2010.5456395","DOIUrl":"https://doi.org/10.1109/WSA.2010.5456395","url":null,"abstract":"We consider transmit beamforming algorithms for single-carrier frequency-division multiple access (SC-FDMA) transmission over frequency-selective multiple-input multiple-output (MIMO) channels. The beamforming filters are designed for optimum performance of MIMO minimum mean-squared error decision-feedback equalization (MMSE-DFE). It turns out that eigenbeamforming diagonalizing the overall channel is optimum, and in addition an optimum power allocation has to be performed which is similar in spirit to classical results for the optimum continuous-time transmit filter for linear modulation formats obtained by Yang and Roy. Simulation results indicate that the proposed solution is beneficial for the block error rate performance of an SC-FDMA transmission scheme with strong channel coding and error-free decisions in the feedback path of MMSE-DFE, which can be guaranteed e.g. by equivalent Tomlinson-Harashima precoding at the transmitter side.","PeriodicalId":311394,"journal":{"name":"2010 International ITG Workshop on Smart Antennas (WSA)","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131901321","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-04-29DOI: 10.1109/WSA.2010.5456424
T. Wiegand, F. Ludwig, S. Paul
Synchronization is a major topic in OFDM. Small remaining timing offsets, which are less than the cyclic prefix, are commonly compensated by the equalizer in the receiver. Therefore, separate detection and compensation of the timing offset, especially the fractional timing offset is not mandatory. Considering a reciprocal communication system, i.e., the uplink channel is assumed to be equal to the transposed downlink channel, for example, downlink precoding can be done by using the estimated uplink channel matrix. In this case a small remaining timing offset, effecting the transfer matrix, corrupts the assumption of reciprocity, and this can cause degradations in the BER. In this paper we consider this effect and show how it can be compensated within the transfer matrix. Furthermore, we analyze in which way the effect differs for different systems mainly caused by the D/A-converter and interpolation filter.
{"title":"Synchronization aspects while using reciprocity for precoding in MIMO-OFDM","authors":"T. Wiegand, F. Ludwig, S. Paul","doi":"10.1109/WSA.2010.5456424","DOIUrl":"https://doi.org/10.1109/WSA.2010.5456424","url":null,"abstract":"Synchronization is a major topic in OFDM. Small remaining timing offsets, which are less than the cyclic prefix, are commonly compensated by the equalizer in the receiver. Therefore, separate detection and compensation of the timing offset, especially the fractional timing offset is not mandatory. Considering a reciprocal communication system, i.e., the uplink channel is assumed to be equal to the transposed downlink channel, for example, downlink precoding can be done by using the estimated uplink channel matrix. In this case a small remaining timing offset, effecting the transfer matrix, corrupts the assumption of reciprocity, and this can cause degradations in the BER. In this paper we consider this effect and show how it can be compensated within the transfer matrix. Furthermore, we analyze in which way the effect differs for different systems mainly caused by the D/A-converter and interpolation filter.","PeriodicalId":311394,"journal":{"name":"2010 International ITG Workshop on Smart Antennas (WSA)","volume":"79 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115081092","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-04-29DOI: 10.1109/WSA.2010.5456392
A. Amah, T. Frank, A. Klein
In this paper, we combine two different multiple access, namely, Space Division Multiple Access (SDMA) and Block-Interleaved Division Multiple Access (B-IFDMA), for uplink transmission, and we name the combined multiple access SD/B-IFDMA. Since SDMA suffers from multiple access interference (MAI) and B-IFDMA from intersymbol interference (ISI), a multi-user detector that can counteract both MAI and ISI is needed for SD/B-IFDMA. We propose three low complexity linear multi-user detectors for SD/B-IFDMA, namely, Zero Forcing (ZF), Minimum Mean Square Error (MMSE) and Non-Iterative Constrained Least Squares (NICLS). The NICLS is a heuristic multi-user detector that tries to improve the performance of ZF without the necessity of having to estimate the noise variance. Additionally, we also address the channel estimation procedure for SD/B-IFDMA by applying orthogonal time multiplexing training and using Chu sequence as the training sequence. Two estimators are considered for channel estimation for SD/B-IFDMA, namely, frequency domain Least Squares (LS) and time domain low complexity Maximum Likelihood (lcML). From bit error performance, it is shown that the MMSE multiuser detector performs best followed by NICLS and ZF. For performance assessment of the channel estimators, ZF multiuser detection is used. It is shown that the lcML outperforms LS with the penalty of having higher computational complexity.
{"title":"On combining SDMA and B-IFDMA: Multi-user detection and channel estimation","authors":"A. Amah, T. Frank, A. Klein","doi":"10.1109/WSA.2010.5456392","DOIUrl":"https://doi.org/10.1109/WSA.2010.5456392","url":null,"abstract":"In this paper, we combine two different multiple access, namely, Space Division Multiple Access (SDMA) and Block-Interleaved Division Multiple Access (B-IFDMA), for uplink transmission, and we name the combined multiple access SD/B-IFDMA. Since SDMA suffers from multiple access interference (MAI) and B-IFDMA from intersymbol interference (ISI), a multi-user detector that can counteract both MAI and ISI is needed for SD/B-IFDMA. We propose three low complexity linear multi-user detectors for SD/B-IFDMA, namely, Zero Forcing (ZF), Minimum Mean Square Error (MMSE) and Non-Iterative Constrained Least Squares (NICLS). The NICLS is a heuristic multi-user detector that tries to improve the performance of ZF without the necessity of having to estimate the noise variance. Additionally, we also address the channel estimation procedure for SD/B-IFDMA by applying orthogonal time multiplexing training and using Chu sequence as the training sequence. Two estimators are considered for channel estimation for SD/B-IFDMA, namely, frequency domain Least Squares (LS) and time domain low complexity Maximum Likelihood (lcML). From bit error performance, it is shown that the MMSE multiuser detector performs best followed by NICLS and ZF. For performance assessment of the channel estimators, ZF multiuser detection is used. It is shown that the lcML outperforms LS with the penalty of having higher computational complexity.","PeriodicalId":311394,"journal":{"name":"2010 International ITG Workshop on Smart Antennas (WSA)","volume":"23 11‐12","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120851536","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-04-29DOI: 10.1109/WSA.2010.5456440
Hamed Mohsenian Rad, J. Mietzner, R. Schober, V. Wong
In this paper, we propose a novel optimization-based pre-equalization filter (PEF) design for multiple-input single-output (MISO) direct-sequence ultra-wideband (DS-UWB) systems with pre-Rake combining. The key feature in our design is that we explicitly take into account spectral mask constraints which are usually imposed by telecommunications regulation and standardization bodies. This avoids the need for an inefficient power back-off, which is necessary for existing pre-equalizer and pre-Rake designs that are designed solely based on average transmit power constraints. Simulation results confirm that the proposed PEF design leads to significant performance gains over UWB PEF structures without any explicit spectral mask considerations. Furthermore, the use of multiple transmit antennas is shown to provide substantial combining gains compared to single-antenna transmitter structures. We also investigate the impact of certain system and optimization parameters on the performance of the proposed PEF design.
{"title":"Optimal MISO UWB pre-equalizer design with spectral mask constraints","authors":"Hamed Mohsenian Rad, J. Mietzner, R. Schober, V. Wong","doi":"10.1109/WSA.2010.5456440","DOIUrl":"https://doi.org/10.1109/WSA.2010.5456440","url":null,"abstract":"In this paper, we propose a novel optimization-based pre-equalization filter (PEF) design for multiple-input single-output (MISO) direct-sequence ultra-wideband (DS-UWB) systems with pre-Rake combining. The key feature in our design is that we explicitly take into account spectral mask constraints which are usually imposed by telecommunications regulation and standardization bodies. This avoids the need for an inefficient power back-off, which is necessary for existing pre-equalizer and pre-Rake designs that are designed solely based on average transmit power constraints. Simulation results confirm that the proposed PEF design leads to significant performance gains over UWB PEF structures without any explicit spectral mask considerations. Furthermore, the use of multiple transmit antennas is shown to provide substantial combining gains compared to single-antenna transmitter structures. We also investigate the impact of certain system and optimization parameters on the performance of the proposed PEF design.","PeriodicalId":311394,"journal":{"name":"2010 International ITG Workshop on Smart Antennas (WSA)","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114964777","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-04-29DOI: 10.1109/WSA.2010.5456438
Nico Palleit, T. Weber
Having the channel state information of the channels over which the signals propagate from the transmitter to the receiver available at both sides of the transmission link is beneficial in many wireless applications. However, in frequency division duplex systems, a base station can only estimate the channel transfer function of the uplink channel based on the transmission of a-priori known training signals from the mobile station. A mobile station can only estimate the channel transfer function of the downlink channel based on the transmission of a-priori known training signals from the base station. Due to the frequency selective behavior of the mobile radio channel, the channel transfer functions of the uplink channel are different from the channel transfer functions of the downlink channel. In order to obtain the channel state information of the downlink channel in the base station or the channel state information of the uplink channel in the mobile station it is possible to feed back this information from the mobile station to the base station or from the base station to the mobile station. However, this feedback of the channel state information decreases the spectral efficiency. This paper introduces novel techniques to obtain the channel state information of the downlink channel in the base station based on the channel state information of the uplink channel in multiple antenna systems. Measurement results show the good performance of the investigated techniques. Thus, the signalling overhead can be reduced.
{"title":"Frequency prediction of the channel transfer function in multiple antenna systems","authors":"Nico Palleit, T. Weber","doi":"10.1109/WSA.2010.5456438","DOIUrl":"https://doi.org/10.1109/WSA.2010.5456438","url":null,"abstract":"Having the channel state information of the channels over which the signals propagate from the transmitter to the receiver available at both sides of the transmission link is beneficial in many wireless applications. However, in frequency division duplex systems, a base station can only estimate the channel transfer function of the uplink channel based on the transmission of a-priori known training signals from the mobile station. A mobile station can only estimate the channel transfer function of the downlink channel based on the transmission of a-priori known training signals from the base station. Due to the frequency selective behavior of the mobile radio channel, the channel transfer functions of the uplink channel are different from the channel transfer functions of the downlink channel. In order to obtain the channel state information of the downlink channel in the base station or the channel state information of the uplink channel in the mobile station it is possible to feed back this information from the mobile station to the base station or from the base station to the mobile station. However, this feedback of the channel state information decreases the spectral efficiency. This paper introduces novel techniques to obtain the channel state information of the downlink channel in the base station based on the channel state information of the uplink channel in multiple antenna systems. Measurement results show the good performance of the investigated techniques. Thus, the signalling overhead can be reduced.","PeriodicalId":311394,"journal":{"name":"2010 International ITG Workshop on Smart Antennas (WSA)","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114802441","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-04-29DOI: 10.1109/WSA.2010.5456428
M. Oispuu, U. Nickel
This paper investigates the three-dimensional passive source localization problem by a system of multiple antenna arrays. It is well-known that centralized and coherent processing of all sensor antenna outputs offers a performance benefit in comparison to decentralized processing, where the latter is easier to implement. We compare the Cramér-Rao bound on the source locations for both cases, review the decentralized direct position determination approach and outline the near-field source localization approach generalized to the three-dimensional problem. Finally, we discuss the trade-off between performance benefit and implementation complexity.
{"title":"3D passive source localization by a multi-array network: Noncoherent vs. coherent processing","authors":"M. Oispuu, U. Nickel","doi":"10.1109/WSA.2010.5456428","DOIUrl":"https://doi.org/10.1109/WSA.2010.5456428","url":null,"abstract":"This paper investigates the three-dimensional passive source localization problem by a system of multiple antenna arrays. It is well-known that centralized and coherent processing of all sensor antenna outputs offers a performance benefit in comparison to decentralized processing, where the latter is easier to implement. We compare the Cramér-Rao bound on the source locations for both cases, review the decentralized direct position determination approach and outline the near-field source localization approach generalized to the three-dimensional problem. Finally, we discuss the trade-off between performance benefit and implementation complexity.","PeriodicalId":311394,"journal":{"name":"2010 International ITG Workshop on Smart Antennas (WSA)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128515843","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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