The Experts below are selected from a list of 38040 Experts worldwide ranked by ideXlab platform
Mamoru Sawahashi - One of the best experts on this subject based on the ideXlab platform.
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field experiments on real time 1 gbps high speed packet transmission in mimo ofdm broadband packet radio access
IEICE Transactions on Communications, 2009Co-Authors: Hidekazu Taoka, Kenichi Higuchi, Mamoru SawahashiAbstract:This paper presents experimental results in real propagation channel environments of real-time 1-Gbps packet transmission using Antenna-dependent adaptive modulation and channel coding (AMC) with 4-by-4 MIMO multiplexing in the downlink Orthogonal Frequency Division Multiplexing (OFDM) radio access. In the experiment, Maximum Likelihood Detection employing QR decomposition and the M-algorithm (QRM-MLD) with adaptive selection of the surviving symbol replica candidates (ASESS) is employed to achieve such a high data rate at a lower received signal-to-interference plus background noise power ratio (SINR). The field experiments, which are conducted at the average moving speed of 30km/h, show that real-time packet transmission of greater than 1Gbps in a 100-MHz channel bandwidth (i.e., 10bits/second/Hz) is achieved at the average received SINR of approximately 13.5dB using 16QAM modulation and turbo coding with the coding rate of 8/9. Furthermore, we show that the measured throughput of greater than 1Gbps is achieved at the probability of approximately 98% in a measurement course, where the maximum distance from the cell site was approximately 300m with the respective transmitter and Receiver Antenna separation of 1.5m and 40cm with the total transmission power of 10W. The results also clarify that the minimum required Receiver Antenna spacing is approximately 10cm (1.5 carrier wave length) to suppress the loss in the required received SINR at 1-Gbps throughput to within 1dB compared to that assuming the fading correlation between Antennas of zero both under non-line-of-sight (NLOS) and line-of-sight (LOS) conditions.
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field experiments on mimo multiplexing with peak frequency efficiency of 50 bit second hz using mld based signal detection for ofdm high speed packet access
IEEE Journal on Selected Areas in Communications, 2008Co-Authors: Hidekazu Taoka, Kenichi Higuchi, Mamoru SawahashiAbstract:This paper presents indoor and field experimental results on extremely high-speed packet transmissions of 4.92 Gbps in a 100 -MHz channel bandwidth, i.e., the frequency efficiency of approximately 50 bit/second/Hz, in the downlink OFDM radio access. The required received signal-to-noise power ratio (SNR) is less than 30dB, which is almost the upper limit in cellular environments near a cell site even with a light channel load, with the aim of application to future universal broadband packet radio access. We apply 12-by-12 MIMO multiplexing using the maximum likelihood detection employing QR decomposition and the M-algorithm (QRM-MLD) with adaptive selection of the surviving symbol replica candidates (ASESS),64QAM data modulation, and Turbo coding with the coding rate of R = 8/9 to achieve an extremely high frequency efficiency level. In the field experiments conducted in the Yokosuka Research Park (YRP) district of Yokosuka city, we show that the measured throughput of 4.92 Gbps is achieved at the average received SNR per Receiver Antenna of approximately 28.0 and 28.5 dB when the respective Receiver Antenna separation is 40 cm (6.2lambda) and 10 cm (1.5lambda) and the transmitter Antenna separation is 70 cm (10.9lambda) at the average speed of 10 km/h under non-line-of-sight (NLOS) conditions.
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field experiments on ultimate frequency efficiency exceeding 30 bit second hz using mld signal detection in mimo ofdm broadband packet radio access
Vehicular Technology Conference, 2007Co-Authors: Hidekazu Taoka, K Dai, Kenichi Higuchi, Mamoru SawahashiAbstract:This paper presents indoor and field experimental results on extremely high-speed packet transmissions of 4.92 Gbps in a 100-MHz channel bandwidth, i.e., the frequency efficiency of approximately 50 bit/second/Hz, in the downlink orthogonal frequency division multiplexing (OFDM) radio access. The required received signal-to-noise power ratio (SNR) is less than 30 dB, which approaches the almost upper limit in cellular environments near a cell site even with a light channel load, with the aim of the application to future universal broadband packet radio access. We apply 12-by-12 MIMO multiplexing using the maximum likelihood detection employing QR decomposition and the M-algorithm (QRM-MLD) with adaptive selection of the surviving symbol replica candidates (ASESS), 64QAM data modulation, and turbo coding with the coding rate of R = 8/9 to achieve an extremely high frequency efficiency level. In the field experiments conducted in the Yokosuka Research Park (YRP) district of Yokosuka city, we show that the measured throughput of 4.92 Gbps is achieved at the average received SNR per Receiver Antenna of approximately 28.0 and 28.5 dB when the Receiver Antenna spacing is 40 cm (6.2lambda), and 10 cm (1.5lambda) at the average speed of 10 km/h, respectively.
Josef Blanz - One of the best experts on this subject based on the ideXlab platform.
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joint detection with coherent Receiver Antenna diversity in cdma mobile radio systems
IEEE Transactions on Vehicular Technology, 1995Co-Authors: Peter Jung, Josef BlanzAbstract:In code division multiple access (CDMA) mobile radio systems, both intersymbol interference and multiple access interference arise which can be combated by using either elaborate optimum or favorable suboptimum joint detection (JD) techniques. Furthermore, the time variation of the radio channels leads to degradations of the Receiver performance. These degradations can be reduced by applying diversity techniques. Using coherent Receiver Antenna diversity (CRAD) is especially attractive because only the signal processing at the Receiver must be modified. In the present paper, the application of CRAD to the more critical uplink of CDMA mobile radio systems with suboptimum JD techniques is investigated for maximal-ratio combining. The authors study six different suboptimum JD techniques based on decorrelating matched filtering, Gauss-Markov estimation, and minimum mean square error estimation with and without decision feedback. These six suboptimum JD techniques which are well-known for single Antenna Receivers are extended for the application to CRAD. A main concern of the paper is the determining of the SNR performance of the presented JD techniques for CRAD and the achievable average uncoded bit error probabilities for the transmission over rural area, typical urban and bad urban mobile radio channels are determined.
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performance of a cellular hybrid c tdma mobile radio system applying joint detection and coherent Receiver Antenna diversity
IEEE Journal on Selected Areas in Communications, 1994Co-Authors: Josef Blanz, Anja Klein, M Nasshan, A SteilAbstract:For future mobile radio systems, an appropriately chosen multiple access technique is a critical issue. Multiple access techniques presently under discussion are code division multiple access (CDMA), time division multiple access (TDMA), and hybrids of both. In the paper, a hybrid C/TDMA system using joint detection (JD-C/TDMA) with coherent Receiver Antenna diversity (CRAD) at the base station (BS) Receiver is proposed. Some attractive features of the JD-C/TDMA system are the possibility to flexibly offer voice and data services with different bit rates, soft capacity, inherent frequency and interferer diversity, and high system capacity due to JD. Furthermore, due to JD, a cluster size equal to 1 can be realized without needing soft handover. The single cell E/sub b//N/sub 0/ performance and the interference situation in a cellular environment of the uplink of a JD-C/TDMA mobile radio system with CRAD is investigated in detail. It is shown that the cellular spectrum efficiency is remarkably high, taking values up to 0.2 bit/s/Hz/BS in the uplink, depending on the actual transmission conditions. >
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performance of a cellular hybrid c tdma mobile radio system applying joint detection and coherent Receiver Antenna diversity
MILCOM '93, 1994Co-Authors: Josef Blanz, Anja Klein, M Nasshan, A SteilAbstract:For future mobile radio systems, an appropriately chosen multiple access technique is a critical issue. Multiple access techniques presently under discussion are code division multiple access (CDMA), time division multiple access (TDMA), and hybrids of both. In this paper, a hybrid C/TDMA system using joint detection (JD-C/TDMA) with coherent Receiver Antenna diversity (CRAD) at the base station (BS) Receiver is proposed. Some attractive features of the JD-C/TDMA system are the possibility to flexibly offer voice and data services with different bit rates, soft capacity, inherent frequency and interferer diversity, and high system capacity due to JD. Furthermore, due to JD, a cluster size equal to 1 can be realized without needing soft handover
D Tholl - One of the best experts on this subject based on the ideXlab platform.
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measurements and modeling of temporal variations of the indoor radio propagation channel
IEEE Transactions on Vehicular Technology, 1994Co-Authors: H Hashemi, M Mcguire, T Vlasschaert, D ThollAbstract:The paper reports the results of extensive measurements and analysis of an indoor radio propagation channel's temporal variations. The empirical data base consists of 192 one-min recordings of CW envelope fading waveforms with both Antennas stationary. Measurements were carried out in an office environment at 1100 MHz with four transmitter-Receiver Antenna separations of 5, 10, 20, and 30 m. Effects of controlled degrees of motion with 0, 1, 2, 3, or 4 individuals walking around the high Antenna only, around the low Antenna only, and around both Antennas were investigated. The reported results include amplitude fading distributions, correlation properties, level crossing rates, duration of fades statistics, and spectrum widths of the frequency domain data, The results can be used in fixed wireless computer communication applications, and in supplementing the available spatial variation models of the indoor radio propagation channel. >
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measurements and modeling of temporal variations of the indoor radio propagation channel
IEEE Transactions on Vehicular Technology, 1994Co-Authors: H Hashemi, M Mcguire, T Vlasschaert, D ThollAbstract:The paper reports the results of extensive measurements and analysis of an indoor radio propagation channel's temporal variations. The empirical data base consists of 192 one-min recordings of CW envelope fading waveforms with both Antennas stationary. Measurements were carried out in an office environment at 1100 MHz with four transmitter-Receiver Antenna separations of 5, 10, 20, and 30 m. Effects of controlled degrees of motion with 0, 1, 2, 3, or 4 individuals walking around the high Antenna only, around the low Antenna only, and around both Antennas were investigated. The reported results include amplitude fading distributions, correlation properties, level crossing rates, duration of fades statistics, and spectrum widths of the frequency domain data, The results can be used in fixed wireless computer communication applications, and in supplementing the available spatial variation models of the indoor radio propagation channel. >
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statistical modeling and simulation of the rms delay spread of indoor radio propagation channels
IEEE Transactions on Vehicular Technology, 1994Co-Authors: H Hashemi, D ThollAbstract:Using a large empirical data base of 12000 impulse response estimates collected in two office buildings the root mean square (rms) delay spread for the individual impulse responses have been calculated and analyzed. Statistical modeling of /spl tau//sub rms/ includes investigation of the local and global distributions, correlations in space, dependence on transmitter-Receiver Antenna separation, correlations with large scale path losses, and dependence on the dynamic range of measurements. Using the results of the statistical analysis, a simulation model capable of generating a set of /spl tau//sub rms/ values for spatially-adjacent points has been developed. >
M Nasshan - One of the best experts on this subject based on the ideXlab platform.
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results on turbo codes for speech transmission in a joint detection cdma mobile radio system with coherent Receiver Antenna diversity
IEEE Transactions on Vehicular Technology, 1997Co-Authors: Peter Jung, M NasshanAbstract:Turbo-codes which are applicable to speech transmission in digital mobile radio systems are treated. Three turbo-codes of different complexity are presented. The proposed turbo-codes are suitable for the application to speech transmission in the joint detection code-division multiple access (JD-CDMA) mobile radio system with coherent Receiver Antenna diversity (CRAD) which are described concisely. The performance of the designed turbo-codes in terms of bit and frame error rates are shown in the case of additive white Gaussian noise (AWGN) channels, flat Rayleigh fading channels, and in the uplink of the aforementioned JD-CDMA mobile radio system.
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performance of a cellular hybrid c tdma mobile radio system applying joint detection and coherent Receiver Antenna diversity
IEEE Journal on Selected Areas in Communications, 1994Co-Authors: Josef Blanz, Anja Klein, M Nasshan, A SteilAbstract:For future mobile radio systems, an appropriately chosen multiple access technique is a critical issue. Multiple access techniques presently under discussion are code division multiple access (CDMA), time division multiple access (TDMA), and hybrids of both. In the paper, a hybrid C/TDMA system using joint detection (JD-C/TDMA) with coherent Receiver Antenna diversity (CRAD) at the base station (BS) Receiver is proposed. Some attractive features of the JD-C/TDMA system are the possibility to flexibly offer voice and data services with different bit rates, soft capacity, inherent frequency and interferer diversity, and high system capacity due to JD. Furthermore, due to JD, a cluster size equal to 1 can be realized without needing soft handover. The single cell E/sub b//N/sub 0/ performance and the interference situation in a cellular environment of the uplink of a JD-C/TDMA mobile radio system with CRAD is investigated in detail. It is shown that the cellular spectrum efficiency is remarkably high, taking values up to 0.2 bit/s/Hz/BS in the uplink, depending on the actual transmission conditions. >
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performance of a cellular hybrid c tdma mobile radio system applying joint detection and coherent Receiver Antenna diversity
MILCOM '93, 1994Co-Authors: Josef Blanz, Anja Klein, M Nasshan, A SteilAbstract:For future mobile radio systems, an appropriately chosen multiple access technique is a critical issue. Multiple access techniques presently under discussion are code division multiple access (CDMA), time division multiple access (TDMA), and hybrids of both. In this paper, a hybrid C/TDMA system using joint detection (JD-C/TDMA) with coherent Receiver Antenna diversity (CRAD) at the base station (BS) Receiver is proposed. Some attractive features of the JD-C/TDMA system are the possibility to flexibly offer voice and data services with different bit rates, soft capacity, inherent frequency and interferer diversity, and high system capacity due to JD. Furthermore, due to JD, a cluster size equal to 1 can be realized without needing soft handover
Hidekazu Taoka - One of the best experts on this subject based on the ideXlab platform.
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experiments on peak spectral efficiency of 50 bps hz with 12 by 12 mimo multiplexing for future broadband packet radio access
International Symposium on Communications Control and Signal Processing, 2010Co-Authors: Hidekazu Taoka, Kenichi HiguchiAbstract:This paper presents field experimental results of peak frequency efficiency of approximately 50 bps/Hz, i.e., 4.9 Gbps packet transmission in a 100-MHz channel bandwidth, using 12-by-12 MIMO-OFDM focusing on the influence of fading correlation between the transmitter and Receiver Antennas using vertically polarized Antennas. Maximum likelihood detection (MLD)-based signal detection was employed to achieve such high frequency efficiency with the required received signal-to-noise power ratio (SNR) of less than 30 dB. From the field experimental results under non-line-of- sight conditions, we show that the required average received SNR to achieve the throughput of 4.9 Gbps is degraded by less than 0.5 dB when the Receiver Antenna separation is reduced from 40 cm (6.2λ) to 10 cm (1.5λ), while it is degraded by approximately 1.5 dB when the transmitter Antenna separation is decreased from 70 cm (10.9λ) to 20 cm (3.1λ). Furthermore, we clarify that the required minimum Antenna separations of the base station transmitter and mobile station Receiver are 20 cm and 10 cm, respectively, in order to achieve the peak throughput of 4.9 Gbps at the average received SNR of less than 30 dB in a field environment.
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field experiments on real time 1 gbps high speed packet transmission in mimo ofdm broadband packet radio access
IEICE Transactions on Communications, 2009Co-Authors: Hidekazu Taoka, Kenichi Higuchi, Mamoru SawahashiAbstract:This paper presents experimental results in real propagation channel environments of real-time 1-Gbps packet transmission using Antenna-dependent adaptive modulation and channel coding (AMC) with 4-by-4 MIMO multiplexing in the downlink Orthogonal Frequency Division Multiplexing (OFDM) radio access. In the experiment, Maximum Likelihood Detection employing QR decomposition and the M-algorithm (QRM-MLD) with adaptive selection of the surviving symbol replica candidates (ASESS) is employed to achieve such a high data rate at a lower received signal-to-interference plus background noise power ratio (SINR). The field experiments, which are conducted at the average moving speed of 30km/h, show that real-time packet transmission of greater than 1Gbps in a 100-MHz channel bandwidth (i.e., 10bits/second/Hz) is achieved at the average received SINR of approximately 13.5dB using 16QAM modulation and turbo coding with the coding rate of 8/9. Furthermore, we show that the measured throughput of greater than 1Gbps is achieved at the probability of approximately 98% in a measurement course, where the maximum distance from the cell site was approximately 300m with the respective transmitter and Receiver Antenna separation of 1.5m and 40cm with the total transmission power of 10W. The results also clarify that the minimum required Receiver Antenna spacing is approximately 10cm (1.5 carrier wave length) to suppress the loss in the required received SINR at 1-Gbps throughput to within 1dB compared to that assuming the fading correlation between Antennas of zero both under non-line-of-sight (NLOS) and line-of-sight (LOS) conditions.
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field experiments on mimo multiplexing with peak frequency efficiency of 50 bit second hz using mld based signal detection for ofdm high speed packet access
IEEE Journal on Selected Areas in Communications, 2008Co-Authors: Hidekazu Taoka, Kenichi Higuchi, Mamoru SawahashiAbstract:This paper presents indoor and field experimental results on extremely high-speed packet transmissions of 4.92 Gbps in a 100 -MHz channel bandwidth, i.e., the frequency efficiency of approximately 50 bit/second/Hz, in the downlink OFDM radio access. The required received signal-to-noise power ratio (SNR) is less than 30dB, which is almost the upper limit in cellular environments near a cell site even with a light channel load, with the aim of application to future universal broadband packet radio access. We apply 12-by-12 MIMO multiplexing using the maximum likelihood detection employing QR decomposition and the M-algorithm (QRM-MLD) with adaptive selection of the surviving symbol replica candidates (ASESS),64QAM data modulation, and Turbo coding with the coding rate of R = 8/9 to achieve an extremely high frequency efficiency level. In the field experiments conducted in the Yokosuka Research Park (YRP) district of Yokosuka city, we show that the measured throughput of 4.92 Gbps is achieved at the average received SNR per Receiver Antenna of approximately 28.0 and 28.5 dB when the respective Receiver Antenna separation is 40 cm (6.2lambda) and 10 cm (1.5lambda) and the transmitter Antenna separation is 70 cm (10.9lambda) at the average speed of 10 km/h under non-line-of-sight (NLOS) conditions.
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field experiments on ultimate frequency efficiency exceeding 30 bit second hz using mld signal detection in mimo ofdm broadband packet radio access
Vehicular Technology Conference, 2007Co-Authors: Hidekazu Taoka, K Dai, Kenichi Higuchi, Mamoru SawahashiAbstract:This paper presents indoor and field experimental results on extremely high-speed packet transmissions of 4.92 Gbps in a 100-MHz channel bandwidth, i.e., the frequency efficiency of approximately 50 bit/second/Hz, in the downlink orthogonal frequency division multiplexing (OFDM) radio access. The required received signal-to-noise power ratio (SNR) is less than 30 dB, which approaches the almost upper limit in cellular environments near a cell site even with a light channel load, with the aim of the application to future universal broadband packet radio access. We apply 12-by-12 MIMO multiplexing using the maximum likelihood detection employing QR decomposition and the M-algorithm (QRM-MLD) with adaptive selection of the surviving symbol replica candidates (ASESS), 64QAM data modulation, and turbo coding with the coding rate of R = 8/9 to achieve an extremely high frequency efficiency level. In the field experiments conducted in the Yokosuka Research Park (YRP) district of Yokosuka city, we show that the measured throughput of 4.92 Gbps is achieved at the average received SNR per Receiver Antenna of approximately 28.0 and 28.5 dB when the Receiver Antenna spacing is 40 cm (6.2lambda), and 10 cm (1.5lambda) at the average speed of 10 km/h, respectively.
