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Papathanassiou Apostolos Furió Ignasi Blanz Josef Johannes Baier Paul Walter 《Wireless Personal Communications》1999,11(1):89-108
Smart antennas for base stations of cellular mobile radio systems offer the potential of system performance enhancement by taking advantage of the directionally inhomogeneous signal reception at the receiver. In this paper, two-dimensional array configurations employed at the uplink receiver of a joint detection CDMA (JD-CDMA) mobile radio system are investigated. This smart antenna concept can be split up into a novel channel estimator and data detector which incorporate explicitely the information of the direction-of-arrival (DOA) of signals emerging from users assigned to the considered base station. Proceeding from channel models that model the directional inhomogeneity of the mobile radio channel with single DOAs, the link level performance of a JD-CDMA mobile radio system using this smart antenna concept is evaluated for the rural propagation environment. The performance evaluation is based on Monte Carlo simulations of data transmission and average bit error rates versus the average signal to noise ratio per net information bit are presented for different array configurations. Although these results should be considered as upper bounds for the link level performance, they reveal the advantages of implementing two-dimensional array configurations at the uplink receiver of a JD-CDMA mobile radio system. 相似文献
2.
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 相似文献
3.
Blanz J. Klein A. Nasshan M. Steil A. 《Selected Areas in Communications, IEEE Journal on》1994,12(4):568-579
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 Eb/N0 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 相似文献
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5.
Peter Jung Josef Blanz Markus Na han Paul Walter Baier 《Wireless Personal Communications》1994,1(1):61-89
Due to time variant multipath propagation, both intersymbol interference and multiple access interference occur at CDMA receivers. These degrading effects can be combatted by joint detection (JD) techniques. In order to reduce the performance impairments resulting from time variance, coherent receiver antenna diversity (CRAD) can be used. In the present paper, a system model of CDMA mobile radio systems using various JD techniques in combination with CRAD shall be considered. This system model is an evolution of the pan-European GSM and takes important real world aspects such as imperfect channel estimation, nonlinear amplification and D/A and A/D conversion into account. The viability of JD with CRAD shall be demonstrated by bit error rate simulations of this system model. It is shown that by using JD with two receiver antennas in bad urban areas,E
b/N0 < 8 dB per antenna is sufficient for a bit error rate of 10–2, andE
b/N0 < 11 dB per antenna is required for a bit error rate of 10–3.List of Abbreviations AWGN
Additive white Gaussian noise
- A/D
Analog-to-digital
- BU
Bad urban
- CDMA
Code division multiple access
- COST
European Co-operation in the Field of Scientific and Technical Research
- CRAD
Coherent receiver antenna diversity
- cdf
Cumulative distribution function
- DMF
Decorrelating matched filter
- DMF-BDFE
Decorrelating matched filter block decision feedback equalizer
- D/A
Digital-to-analog
- EGC
Equal-gain combining
- FDMA
Frequency division multiple access
- GMSK
Gaussian minimum shift keying
- GSM
Global System for Mobile Communications
- ISI
Intersymbol interference
- JD
Joint detection
- JDC
Japanese Digital Cellular
- JD-CDMA
Joint detection code division multiple access
- MA
Multiple access
- MAI
Multiple access interference
- MMSE-BLE
Minimum mean square error block linear equalizer
- MMSE-BDFE
Minimum mean square error block decision feedback equalizer
- MRC
Maximal-ratio combining
- RA
Rural area
- SC
Selection combining
- SNR
Signal-to-noise ratio
- TDMA
Time division multiple access
- TU
Typical urban
- WSSUS
Wide sense stationary uncorrelated scattering
- ZF-BLE
Zero forcing block linear equalizer
- ZF-BDFE
Zero forcing block decision feedback equalizer 相似文献
6.
M. Hampele D. Herlach A. Kratzer G. Majer J. Major H. -P. Raich R. Roth C. A. Scott A. Seeger W. Templ M. Blanz S. F. J. Cox K. Fürderer 《Hyperfine Interactions》1991,65(1-4):1081-1087
Resonant transitions between the Zeeman levels of positive muons implanted into α-iron foils have been observed above the
Curie temperature by applying a 17.8 MHz transverse radio-frequency field and varying the longitudinal external field. Resonance
signals of free and trapped muons are detected. 相似文献
7.
71 The architecture, implementation, and application of GANGLION, a totally digital connectionist classifier, are described. This fully interconnected feedforward net with one hidden layer is capable of generating 4.48 billion interconnection/s. The architecture is realized on a single 9U VME card and is built entirely from off-the-shelf components. The very high throughput of 20 million decision/s is achieved by making efficient use of field-programmable gate arrays. Specifically, the authors take advantage of the reprogrammability of the devices to automatically generate new custom hardware for each application of the classifier 相似文献
8.
Blanz J.J. Papathanassiou A. Haardt M. Furio I. Baier P.W. 《Vehicular Technology, IEEE Transactions on》2000,49(2):293-306
In cellular mobile radio systems, the directional inhomogeneity of the mobile radio channel can be exploited by smart antennas to increase the spectral efficiency. In this paper, a novel smart antenna concept applying receiver antenna diversity at the uplink receiver is investigated for a time-slotted code-division multiple-access (CDMA) mobile radio air interface termed time-division CDMA (TD-CDMA), which has been selected by the European Telecommunications Standards Institute (ETSI) in January 1998 to form part of the Universal Mobile Telecommunications System (UMTS) air interface standard. First, a combined direction-of-arrival (DOA) and joint channel estimation scheme is presented, which is based on DOA estimation using the Unitary ESPRIT algorithm and maximum likelihood estimation of the channel impulse responses associated with the estimated DOA's, which can also be used as an input for advanced mobile positioning schemes in UMTS. The performance of the combined DOA and joint channel estimation is compared with the conventional channel estimation through simulations in rural and urban propagation environments. Moreover, a novel joint data detection scheme is considered, which explicitly takes into account the signal DOA's and the associated channel impulse responses. The link level performance of a TD-CDMA mobile radio system using these novel schemes is evaluated by Monte Carlo simulations of data transmission, and average bit error rates (BER's) are determined for rural and urban propagation environments. The simulation results indicate that, depending on the propagation environment, the exploitation of the knowledge of the directional inhomogeneity of the mobile radio channel can lead to considerable system performance enhancements 相似文献
9.
The application of multiple directive antennas, i.e., directional diversity, may lead to significant capacity benefits in cellular mobile radio systems. A flexibly configurable statistical channel model for mobile radio systems using directional diversity is presented. The parameters of this model, which is available as a FORTRAN77 program, can be easily adjusted to various propagation areas such as, for example, rural, urban, microcellular, and picocellular environments. Therefore, the model is well suited to perform simulations, evaluations, and comparisons of mobile radio systems. Simulation results concerning a code-division multiple-access (CDMA) mobile radio system which uses multiple directive base station (BS) antennas in combination with joint detection illustrate the application of the presented channel model 相似文献
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