Results 1 - 10
of
12
Spherical-wave model for short-range MIMO
- IEEE Transactions on Communications
, 2005
"... Abstract—The plane-wave assumption has been used extensively in array signal processing, parameter estimation, and wireless channel modeling to simplify analysis. It is suitable for single-input single-output and single-input multiple-output systems, because the rank of the channel matrix is one. Ho ..."
Abstract
-
Cited by 16 (2 self)
- Add to MetaCart
(Show Context)
Abstract—The plane-wave assumption has been used extensively in array signal processing, parameter estimation, and wireless channel modeling to simplify analysis. It is suitable for single-input single-output and single-input multiple-output systems, because the rank of the channel matrix is one. However, for short-range multiple-input multiple-output (MIMO) channels with a line-of-sight (LOS) component, the plane-wave assumption affects the rank and singular value distribution of the MIMO channel matrix, and results in the underestimation of the channel capacity, especially for element spacings exceeding half a wavelength. The short-range geometry could apply to many indoor wireless local area network applications. To avoid this underestimation problem, the received signal phases must depend precisely on the distances between transmit and receive antenna elements. With this correction, the capacity of short-range LOS MIMO channels grows steadily as the element spacing exceeds half a wavelength, as confirmed by measurements at 5.8 GHz. In contrast, the capacity growth with element spacing diminishes significantly under the plane-wave assumption. Using empirical fitting, we provide a threshold distance below which the spherical-wave model is required for accurate performance estimation in ray tracing. Index Terms—Channel capacity, line-of-sight (LOS), multiple-input multiple-output (MIMO), plane-wave model, ray tracing, spherical-wave model. I.
On the capacity of MIMO Rice channels
- in Proceedings of the 42nd Allerton Conference
, 2004
"... The asymptotic --in the number of antennas-- theoretic capacity of a MIMO (Multiple Input Multiple Output) system is derived when considering Rice distribution entries. Assuming perfect knowledge of the channel at the receiver, analytical expressions of the capacity are derived in the case of per ..."
Abstract
-
Cited by 13 (2 self)
- Add to MetaCart
(Show Context)
The asymptotic --in the number of antennas-- theoretic capacity of a MIMO (Multiple Input Multiple Output) system is derived when considering Rice distribution entries. Assuming perfect knowledge of the channel at the receiver, analytical expressions of the capacity are derived in the case of perfect and partial (based on the mean and limiting eigenvalue distribution of the mean) knowledge at the transmitter. Remarkably, the capacity depends only on a few meaningful parameters, namely, the limiting eigenvalue distribution of the mean matrix, the signal to noise ratio (SNR), the Ricean factor, and the system load. These results show in particular that, for a given SNR and in contrast to the SISO (Single Input Single Output) case, the MIMO Rice channel does not always outperform the MIMO Rayleigh channel in terms of capacity. Moreover, the results are also useful to quantify the effect of feedback on general MIMO systems.
Øien, “Construction and capacity analysis of high-rank line-of-sight MIMO channels
- in Proc. of IEEE WCNC
, 2005
"... Abstract — This paper describes a technique for realizing a high rank channel matrix in a line-of-sight (LOS) multiple-input-multiple-output (MIMO) transmission scenario. This is beneficial for systems which can not make use of the originally derived MIMO gain given by independent and identically di ..."
Abstract
-
Cited by 12 (2 self)
- Add to MetaCart
(Show Context)
Abstract — This paper describes a technique for realizing a high rank channel matrix in a line-of-sight (LOS) multiple-input-multiple-output (MIMO) transmission scenario. This is beneficial for systems which can not make use of the originally derived MIMO gain given by independent and identically distributed (i.i.d.) flat Rayleigh fading channels. Typical applications are fixed wireless access and radio relay systems. The technique is based on optimization of antenna placement in a uniform linear array. By introducing a new and more general geometrical model than that applied in earlier works, additional insight into the optimal design parameters is gained. A novel analysis of the sensitivity of the optimal design parameters is performed. The LOS transmission matrix is used in a Ricean fading channel model, and performance is evaluated with respect to ergodic capacity, outage capacity, and effective degrees of freedom. The results show that even with some deviation from optimal design, the LOS MIMO case outperforms the i.i.d. Rayleigh case in terms of Shannon capacity. Keywords—MIMO, Rice channel, line-of-sight, uniform linear array, Shannon capacity. I.
Enhancing Measured Mimo Capacity By Adapting The Locations Of The Antenna Elements
- IEEE International Symposium on Personal, Indoor, and Mobile Radio Communications
, 2002
"... We show that the multiple-input, multipleoutput (MIMO) capacity of measured, indoor flat-fading channels may be improved by adaptively changing the locations of the antenna elements. Moving the antenna elements is a way to provide spatial diversity to a MIMO link without decreasing the number of par ..."
Abstract
-
Cited by 5 (4 self)
- Add to MetaCart
(Show Context)
We show that the multiple-input, multipleoutput (MIMO) capacity of measured, indoor flat-fading channels may be improved by adaptively changing the locations of the antenna elements. Moving the antenna elements is a way to provide spatial diversity to a MIMO link without decreasing the number of parallel data streams. First, we demonstrate that significant variations in equalpower capacity are possible using measured data from finely sampled virtual arrays at both ends of a MIMO link. Second, using steepest descent and a simulated path-type channel derived from measured data, we adapt the element locations. In line-of-sight (LOS) and obstructed-line-of-sight (OLOS) examples, the local maximum capacity is reached within 5 and 10 iterations, respectively. The improvements relative to the equally spaced arrays are approximately 22% and 19%, respectively.
A line-of-sight optimised MIMO architecture for outdoor environments
- in Proc. IEEE Vehicular Technology Conf. (VTC
, 2006
"... This document is made available in accordance with publisher policies. Please cite only the published version using the reference above. Full terms of use are available: ..."
Abstract
-
Cited by 1 (0 self)
- Add to MetaCart
This document is made available in accordance with publisher policies. Please cite only the published version using the reference above. Full terms of use are available:
Line-of-Sight MIMO for Microwave Links Adaptive Dual Polarized and Spatially Separated Systems
, 2009
"... the non-exclusive right to publish the Work electronically and in a non-commercial purpose make it accessible on the Internet. The Author warrants that he/she is the author to the Work, and warrants that the Work does not contain text, pictures or other material that violates copyright law. The Auth ..."
Abstract
- Add to MetaCart
(Show Context)
the non-exclusive right to publish the Work electronically and in a non-commercial purpose make it accessible on the Internet. The Author warrants that he/she is the author to the Work, and warrants that the Work does not contain text, pictures or other material that violates copyright law. The Author shall, when transferring the rights of the Work to a third party (for example a publisher or a company), acknowledge the third party about this agreement. If the Author has signed a copyright agreement with a third party regarding the Work, the Author warrants hereby that he/she has obtained any necessary permission from this third party to let Chalmers University of Technology and University of Gothenburg store the Work electronically and make it accessible on the Internet. Line-of-Sight MIMO for Microwave Links
On the Boundaries of the MIMO-Channel-Capacity with a Focus on Line-of-Sight-Connections
, 2004
"... This paper is dedicated to Professor Karlheinz Tröndle on the ocassion of his 65th birthday ..."
Abstract
- Add to MetaCart
(Show Context)
This paper is dedicated to Professor Karlheinz Tröndle on the ocassion of his 65th birthday
Author manuscript, published in "IEEE VTC Spring 2012, Yokphama: Japan (2012)" DOI: 10.1109/VETECS.2012.6240062 Simulation Analysis of Wireless Channel Effect on IEEE 802.11n Physical Layer
, 2013
"... Abstract � IEEE 802.11n standard came as a rescue; the existing standards are increasingly seen as inadequate since applications become more complex and require more bandwidth. Several techniques have been put into operation to meet two basic requirements: significantly greater bit rate and radio co ..."
Abstract
- Add to MetaCart
Abstract � IEEE 802.11n standard came as a rescue; the existing standards are increasingly seen as inadequate since applications become more complex and require more bandwidth. Several techniques have been put into operation to meet two basic requirements: significantly greater bit rate and radio coverage. However, studies have shown that the theoretical limit in terms of throughput is far from being reached and that the received power does not explain the performance degradation. A list of suspect parameters is analyzed in this paper to assess their effect on performance of the IEEE 802.11n physical layer taken as an application of MIMO technology in indoor context. It is shown that for values of angular spread below 27°, the data rate cannot exceed 117 Mbps and the antennas spacing can compensate the performance degradation caused by other parameters. Results are given in terms of correlation coefficient, other channel characteristics and the packet error rate.
Achieving Practical MIMO Network Planning Using the Two-Curve MIMO Performance Model
"... To propel MIMO networks into ubiquity, there is a great need for a fast, intuitive network planning model which can predict the performance of a MIMO system that includes site-specific information. Most models of MIMO communication focus on the characterization of measured data and do not emphasize ..."
Abstract
- Add to MetaCart
(Show Context)
To propel MIMO networks into ubiquity, there is a great need for a fast, intuitive network planning model which can predict the performance of a MIMO system that includes site-specific information. Most models of MIMO communication focus on the characterization of measured data and do not emphasize site-specific predictive
