| 51. |
- Gustafson, Carl, et al.
(författare)
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On mm-Wave Multi-path Clustering and Channel Modeling
- 2014
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Ingår i: IEEE Transactions on Antennas and Propagation. - 0018-926X. ; 62:3, s. 1445-1455
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Tidskriftsartikel (refereegranskat)abstract
- Efficient and realistic mm-wave channel models are of vital importance for the development of novel mm-wave wireless technologies. Though many of the current 60 GHz channel models are based on the useful concept of multi-path clusters, only a limited number of 60 GHz channel measurements have been reported in the literature for this purpose. Therefore, there is still a need for further measurement based analyses of multi-path clustering in the 60 GHz band. This paper presents clustering results for a double-directional 60 GHz MIMO channel model. Based on these results, we derive a model which is validated with measured data. Statistical cluster parameters are evaluated and compared with existing channel models. It is shown that the cluster angular characteristics are closely related to the room geometry and environment, making it infeasible to model the delay and angular domains independently. We also show that when using ray tracing to model the channel, it is insufficient to only consider walls, ceiling, floor and tables; finer structures such as ceiling lamps, chairs and bookshelves need to be taken into account as well.
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| 52. |
- Haneda, Katsuyuki, et al.
(författare)
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Comparison of angular and delay spreads between channel measurements and the COST channel model
- 2010
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Ingår i: ; , s. 477-480
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Konferensbidrag (refereegranskat)abstract
- The COST2100 channel model is a reference channel model which provides dynamic multiple-input multiple-output channel responses for radio system simulations. In this paper, channels created by the COST2100 model were compared to channel measurements in order to understand behaviours of the model. Model parameters of the COST2100 model were derived by dynamic double-directional channel measurements with which the channel realizations from the COST2100 model were compared. Delay and angular spreads were used as a simple but important metric for the comparison. Despite a fundamental difference that the COST2100 model is a geometry- based stochastic model while the channel measurements are ob- tained in deterministic environments, the comparison revealed an acceptable level of agreement for practical channel simulations.
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| 53. |
- Haneda, Katsuyuki, et al.
(författare)
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Comparison of delay and angular spreads between channel measurements and the COST2100 channel model
- 2010
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Ingår i: 2010 Loughborough Antennas and Propagation Conference, LAPC 2010. - 9781424473052 ; , s. 477-480
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Konferensbidrag (refereegranskat)abstract
- The COST2100 channel model is a reference channel model which provides dynamic multiple-input multiple-output channel responses for radio system simulations. In this paper, channels created by the COST2100 model were compared to channel measurements in order to understand behaviours of the model. Model parameters of the COST2100 model were derived by dynamic double-directional channel measurements with which the channel realizations from the COST2100 model were compared. Delay and angular spreads were used as a simple but important metric for the comparison. Despite a fundamental difference that the COST2100 model is a geometry-based stochastic model while the channel measurements are obtained in deterministic environments, the comparison revealed an acceptable level of agreement for practical channel simulations
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| 54. |
- Haneda, Katsuyuki, et al.
(författare)
-
Feasibility study of a mm-wave impulse radio using measured radio channels
- 2011
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Ingår i: [Host publication title missing]. - 1550-2252. - 9781424483327
-
Konferensbidrag (refereegranskat)abstract
- Abstract in UndeterminedA millimeter-wave (mm-wave) impulse radio is an attractive alternative to existing high-speed mm- wave radio systems because of the potential for a simpler transceiver architecture. This paper studies the feasibility of a mm-wave impulse radio system for home and office use by considering state-of-the- art transceivers and multiple-input multiple-output measured propagation channels as well as the IEEE 802.15.3c channel model. Our analysis reveals that reliable data transmission is infeasible even in line-of-sight (LOS) scenarios because of a low power level at the Rx if we do not use beamforming. However, introducing 7×7 beamforming at the Tx dramatically improves the coverage beyond 5 m distance in the LOS scenario and up to 5 m in a non- line-of-sight (NLOS) scenario, though the performance varies in the NLOS scenario, depending on the Tx and Rx locations. We propose an adaptive transmit signaling scheme that adjusts the pulse repetition frequency depending on the delay dispersion of the propagation channel in order to avoid intersymbol interference and keep the Rx structure simple. The proposed transmit signaling scheme leads to a pulse transmission rate of 250 Mpulses/s in all measured channels while the rate is lower when the 802.15.3c model is considered because of a more multipath-rich characteristics than our measured channels.
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| 55. |
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| 56. |
- He, Ruisi, et al.
(författare)
-
Vehicle-to-vehicle channel models with large vehicle obstructions
- 2014
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Ingår i: [Host publication title missing]. ; , s. 5647-5652
-
Konferensbidrag (refereegranskat)abstract
- Vehicle-to-Vehicle (V2V) communication is an en-abler for improved traffic safety and congestion control. As for any wireless system the ultimate performance limit is determined by the propagation channel. A particular point of interest is the shadowing effect of large vehicles such as trucks and buses, as this might affect the communication range significantly. In this paper we present measurement results and model the propagation channel in which a bus acts as a shadowing object between two passenger cars. The measurement setup is based on a WARP FPGA software radio as transmitter, and a Tektronix RSA5106A real-time complex spectrum analyzer as receiver. We analyze the influence of the bus location and car separation distance on the large-scale path loss, shadowing, and small-scale fading. The main effect of the bus is that it is acting as an obstruction creating an additional 15-20 dB attenuation. A Nakagami distribution is found to describe the statistics of the small-scale fading, by using Akaike's Information Criterion and the Kolmogorov-Smirnov test. The distance-dependency of the path loss is analyzed, and a stochastic model is developed to reflect the impact.
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| 57. |
- He, Ruisi, et al.
(författare)
-
Vehicle-to-Vehicle Propagation Models With Large Vehicle Obstructions
- 2014
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Ingår i: IEEE Transactions on Intelligent Transportation Systems. - 1524-9050. ; 15:5, s. 2237-2248
-
Tidskriftsartikel (refereegranskat)abstract
- Vehicle-to-vehicle (V2V) communication is an enabler for improved traffic safety and congestion control. As for any wireless system, the ultimate performance limit is determined by the propagation channel. A particular point of interest is the shadowing effect of large vehicles such as trucks and buses, as this might affect the communication range significantly. In this paper we present measurement results and model the propagation channel, in which a bus acts either as a shadowing object or as a relay between two passenger cars. The measurement setup is based on a Wireless Open-Access Research Platform (WARP) Field-Programmable Gate Array (FPGA) software radio as transmitter and a Tektronix RSA5106A real-time complex spectrum analyzer as receiver. We analyze the influence of the bus location and car separation distance on the path loss, shadowing, small-scale fading, delay spread, and cross correlation. The main effect of the bus is that it is acting as an obstruction creating an additional 15- to 20-dB attenuation and an increase in the root-mean-square delay spread by roughly 100 ns. A Nakagami distribution is found to well describe the statistics of the small-scale fading, by using Akaike's Information Criterion and the Kolmogorov-Smirnov test. The distance dependence of the path loss is analyzed and a stochastic model is developed.
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| 58. |
- Hult, Tommy, et al.
(författare)
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Analytical dual-link MIMO channel model using correlated correlation matrices
- 2010
-
Ingår i: Proceedings of the Fourth European Conference on Antennas and Propagation. - 9788476534724 - 9781424464319
-
Konferensbidrag (refereegranskat)abstract
- Analytical Multiple-Input Multiple-Output (MIMO) models are often attractive due to their low complexity when analyzing possibilities and limitations in the system. In this paper we outline a a possible dual link extension of an analytical MIMO channel model and investigate its suitability based on measurements of a dual link MIMO scenario. The extension is based on the correlation matrix distance (CMD) as a gauge to generate correlation matrices for the additional links of the multi-link scenario.
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| 59. |
- Khan, Muhammad Gufran, et al.
(författare)
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Non-coherent detection of impulse radio UWB signals based on fourth order statistics
- 2011
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Ingår i: Wireless Personal Communications. - : Springer Science and Business Media LLC. - 1572-834X .- 0929-6212.
-
Tidskriftsartikel (refereegranskat)abstract
- Low-complex and low power non-coherent energy detector (ED) is interesting for low data rate impulse radio (IR) ultra wideband (UWB) systems but, compared to coherent receivers, it suffers from a loss in performance due to low signal-to-noise ratio (SNR) at the detector. In addition, the performance of an ED strongly depends on the integration interval (window size) of the integrator and the window position. A non-coherent kurtosis detector (KD) and a fourth-order detector (FD), which can discriminate between Gaussian noise signals and non-Gaussian IR-UWB signals by directly estimating the fourth-order moment of the received signal, are presented. The performance of the detectors is evaluated using real channels measured in a corridor, an office and a laboratory environment. The results show that bit-error-rate (BER) performance of the proposed KD receiver is better than the ED receiver only under certain conditions, while the FD receiver is slightly better than the ED in low SNR region and its performance improves as the SNR increases. In addition, the performance of the FD receiver is less sensitive to overestimation of the integration interval making it relatively robust to variations of the channel delay spread. Finally, a criteria for the selection of integration time of the proposed detector is suggested.
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| 60. |
- Khan, Muhammad Gufran, et al.
(författare)
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Non-Coherent Fourth-Order Detector for Impulse Radio Ultra Wideband Systems : Empirical Evaluation Using Channel Measurements
- 2013
-
Ingår i: Wireless personal communications. - : Springer. - 0929-6212 .- 1572-834X. ; 68:1, s. 27-46
-
Tidskriftsartikel (refereegranskat)abstract
- Low-complex and low-power non-coherent energy detectors (EDs) are interesting for low data rate impulse radio (IR) ultra wideband (UWB) systems, but suffer from a loss in performance compared to coherent receivers. The performance of an ED also strongly depends on the integration interval (window size) of the integrator and the window position. This paper presents a non-coherent fourth-order detector (FD) which can discriminate between Gaussian noise signals and non-Gaussian IR-UWB signals by directly estimating the fourth-order moment of the received signal. The performance of the detectors is evaluated using realistic channels measured in a corridor, an office and a laboratory environment. The results show that bit-error-rate (BER) performance of the proposed FD receiver is slightly better than the ED in low signal-to-noise ratio (SNR) region and its performance improves as the SNR increases. In addition, BER of the FD receiver is less sensitive to overestimation of the integration interval making it relatively robust to variations of the channel delay spread. Finally, a criteria for the selection of integration time of the proposed detector is suggested.
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