Thu, 24 Jul 2008 23:19:53 BST CiteULike: dcastros Valenzuela http://www.citeulike.org/user/dcastro/author/Valenzuela CiteULike.org en-gb Copyright © 2004-2008 citeulike.org http://www.citeulike.org/user/dcastro/article/2923563 <i>Vehicular Technology Conference, 1996. 'Mobile Technology for the Human Race'., IEEE 46th, Vol. 1 (1996), pp. 1-5 vol.1.</i><br /><br />Wireless products and systems are quickly becoming an integral part of professional and private life styles and are being used in a large variety of vehicular, public and private environments. The design of these systems requires an accurate characterization of the communications channel defined by the transmitting and receiving antennas and the specific propagation characteristics of the radio link involved. This paper surveys the typical antenna design choices as well as the various propagation models applicable to modern wireless communications systems Antennas and propagation for wireless communications RA Valenzuela doi:10.1109/VETEC.1996.503396 Vehicular Technology Conference, 1996. 'Mobile Technology for the Human Race'., IEEE 46th, Vol. 1 (1996), pp. 1-5 vol.1. 2008-06-24T12:41:21-00:00 1996 Vehicular Technology Conference, 1996. 'Mobile Technology for the Human Race'., IEEE 46th 1 1 5 vol.1 antenna communication propagation wireless http://www.citeulike.org/user/dcastro/article/2709709 <i>Communications Magazine, IEEE, Vol. 39, No. 9. (2001), pp. 156-162.</i><br /><br />The explosive growth of both the wireless industry and the Internet is creating a huge market opportunity for wireless data access. Limited Internet access, at very low speeds, is already available as an enhancement to some existing cellular systems. However, those systems were designed with the purpose of providing voice services and-at most-short messaging, but not fast data transfers. In fact, as shown in this article, traditional wireless technologies are not very well suited to meet the demanding requirements of providing very high data rates with the ubiquity, mobility, and portability characteristic of cellular systems. Increased use of antenna arrays appears to be the only means of enabling the types of data rates and capacities needed for wireless Internet and multimedia services. While the deployment of base station arrays is becoming universal, it is really the simultaneous deployment of base station and terminal arrays that can unleash unprecedented levels of performance by opening up multiple spatial signaling dimensions Lifting the limits on high speed wireless data access using antenna arrays A Lozano FR Farrokhi RA Valenzuela doi:10.1109/35.948420 Communications Magazine, IEEE, Vol. 39, No. 9. (2001), pp. 156-162. 2008-04-23T18:15:09-00:00 2001 Communications Magazine, IEEE 39 9 156 162 antenna array wireless http://www.citeulike.org/user/dcastro/article/784256 <i>Information Theory, IEEE Transactions on, Vol. 48, No. 3. (2002), pp. 637-650.</i><br /><br />Previous studies have shown that single-user systems employing n-element antenna arrays at both the transmitter and the receiver can achieve a capacity proportional to n, assuming independent Rayleigh fading between antenna pairs. We explore the capacity of dual-antenna-array systems under correlated fading via theoretical analysis and ray-tracing simulations. We derive and compare expressions for the asymptotic growth rate of capacity with n antennas for both independent and correlated fading cases; the latter is derived under some assumptions about the scaling of the fading correlation structure. In both cases, the theoretic capacity growth is linear in n but the growth rate is 10-20% smaller in the presence of correlated fading. We analyze our assumption of separable transmit/receive correlations via simulations based on a ray-tracing propagation model. Results show that empirical capacities converge to the limit capacity predicted from our asymptotic theory even at moderate n = 16. We present results for both the cases when the transmitter does and does not know the channel realization Capacity scaling in MIMO wireless systems under correlated fading Chen-Nee Chuah DNC Tse JM Kahn RA Valenzuela doi:10.1109/18.985982 Information Theory, IEEE Transactions on, Vol. 48, No. 3. (2002), pp. 637-650. 2006-08-03T09:22:15-00:00 2002 Information Theory, IEEE Transactions on 48 3 637 650 capacity fading mimo wireless http://www.citeulike.org/user/dcastro/article/2397693 <i>Personal, Indoor and Mobile Radio Communications, 2002. The 13th IEEE International Symposium on, Vol. 4 (2002), pp. 1626-1630 vol.4.</i><br /><br />The paper presents a multiple-input-multiple-output (MIMO) channel modeling technique for link level and system level simulations. The classical approach of wave superposition is adopted to generate MIMO channels that are statistically consistent in delay, frequency and angle domains. The paper proposes an efficient way to generate four dimensional MIMO channel transfer matrices based on standard channel statistics such as power delay profile (PDP) and power azimuth spectrum (PAS). A wave-based wideband MIMO channel modeling technique H Xu D Chizhik H Huang R Valenzuela Personal, Indoor and Mobile Radio Communications, 2002. The 13th IEEE International Symposium on, Vol. 4 (2002), pp. 1626-1630 vol.4. 2008-02-19T08:19:21-00:00 2002 Personal, Indoor and Mobile Radio Communications, 2002. The 13th IEEE International Symposium on 4 1626 1630 vol.4 channel mimo model wideband http://www.citeulike.org/user/dcastro/article/2397692 <i>Signals, Systems and Computers, 2004. Conference Record of the Thirty-Eighth Asilomar Conference on, Vol. 1 (2004), pp. 305-309 Vol.1.</i><br /><br />Inspired by recent advances in multiple-input multiple-output (MIMO) communications, this paper introduces the statistical MIMO radar concept. The fundamental difference between statistical MIMO and other radar array systems is that the latter seek to maximize the coherent processing gain, while statistical MIMO radar capitalizes on the diversity of target scattering to improve radar performance. Coherent processing is made possible by highly correlated signals at the receiver array, whereas in statistical MIMO radar, the signals received by the array elements are uncorrelated. It is well known that in conventional radar, slow fluctuations of the target radar cross-section (RCS) result in target fades that degrade radar performance. By spacing the antenna elements at the transmitter and at the receiver such that the target angular spread is manifested, the MIMO radar can exploit the spatial diversity of target scatterers opening the way to a variety of new techniques that can improve radar performance. In this paper, we focus on the application of the target spatial diversity to improve detection performance. The optimal detector in the Neyman-Pearson sense is developed and analyzed for the statistical MIMO radar. An optimal detector invariant to the signal and noise levels is also developed and analyzed. In this case as well, statistical MIMO radar provides great improvements over other types of array radars. Performance of MIMO radar systems: advantages of angular diversity E Fishler A Haimovich R Blum R Cimini D Chizhik R Valenzuela doi:10.1109/ACSSC.2004.1399142 Signals, Systems and Computers, 2004. Conference Record of the Thirty-Eighth Asilomar Conference on, Vol. 1 (2004), pp. 305-309 Vol.1. 2008-02-19T08:18:57-00:00 2004 Signals, Systems and Computers, 2004. Conference Record of the Thirty-Eighth Asilomar Conference on 1 305 309 Vol.1 mimo radar http://www.citeulike.org/user/dcastro/article/838417 <i>Signals, Systems, and Electronics, 1998. ISSSE 98. 1998 URSI International Symposium on (1998), pp. 295-300.</i><br /><br />Information theory research has shown that the rich-scattering wireless channel is capable of enormous theoretical capacities if the multipath is properly exploited. In this paper, we describe a wireless communication architecture known as vertical BLAST (Bell Laboratories Layered Space-Time) or V-BLAST, which has been implemented in real-time in the laboratory. Using our laboratory prototype, we have demonstrated spectral efficiencies of 20-40 bps/Hz in an indoor propagation environment at realistic SNRs and error rates. To the best of our knowledge, wireless spectral efficiencies of this magnitude are unprecedented and are furthermore unattainable using traditional techniques V-BLAST: an architecture for realizing very high data rates over the rich-scattering wireless channel PW Wolniansky GJ Foschini GD Golden RA Valenzuela Signals, Systems, and Electronics, 1998. ISSSE 98. 1998 URSI International Symposium on (1998), pp. 295-300. 2006-09-10T03:17:49-00:00 1998 Signals, Systems, and Electronics, 1998. ISSSE 98. 1998 URSI International Symposium on 295 300 broadband channel mimo wireless http://www.citeulike.org/user/dcastro/article/670383 <i>Radar Conference, 2004. Proceedings of the IEEE (2004), pp. 71-78.</i><br /><br />It has recently been shown that multiple-input multiple-output (MIMO) antenna systems have the potential to improve dramatically the performance of communication systems over single antenna systems. Unlike beamforming, which presumes a high correlation between signals either transmitted or received by an array, the MIMO concept exploits the independence between signals at the array elements. In conventional radar, target scintillations are regarded as a nuisance parameter that degrades radar performance. The novelty of MIMO radar is that it takes the opposite view; namely, it capitalizes on target scintillations to improve the radar's performance. We introduce the MIMO concept for radar. The MIMO radar system under consideration consists of a transmit array with widely-spaced elements such that each views a different aspect of the target. The array at the receiver is a conventional array used for direction finding (DF). The system performance analysis is carried out in terms of the Cramer-Rao bound of the mean-square error in estimating the target direction. It is shown that MIMO radar leads to significant performance improvement in DF accuracy. MIMO radar: an idea whose time has come E Fishler A Haimovich R Blum D Chizhik L Cimini R Valenzuela Radar Conference, 2004. Proceedings of the IEEE (2004), pp. 71-78. 2006-05-25T18:23:25-00:00 2004 Radar Conference, 2004. Proceedings of the IEEE 71 78 mimo radar http://www.citeulike.org/user/dcastro/article/117306 <i>Selected Areas in Communications, IEEE Journal on, Vol. 5, No. 2. (1987), pp. 128-137.</i><br /><br />The results of indoor multipath propagation measurements using 10 ns, 1.5 GHz, radarlike pulses are presented for a medium-size office building. The observed channel was very slowly time varying, with the delay spread extending over a range up to about 200 ns and rms values of up to about 50 ns. The attenuation varied over a 60 dB dynamic range. A simple statistical multipath model of the indoor radio channel is also presented, which fits our measurements well, and more importantly, appears to be extendable to other buildings. With this model, the received signal rays arrive in clusters. The rays have independent uniform phases, and independent Rayleigh amplitudes with variances that decay exponentially with cluster and ray delays. The clusters, and the rays within the cluster, form Poisson arrival processes with different, but fixed, rates. The clusters are formed by the building superstructure, while the individual rays are formed by objects in the vicinities of the transmitter and the receiver. A Statistical Model for Indoor Multipath Propagation A Saleh R Valenzuela Selected Areas in Communications, IEEE Journal on, Vol. 5, No. 2. (1987), pp. 128-137. 2005-03-08T13:55:53-00:00 1987 Selected Areas in Communications, IEEE Journal on 5 2 128 137 delay indoor inserted-bib model multipath propagation ray statistical