共查询到20条相似文献,搜索用时 265 毫秒
1.
Chen Jie Vidhyacharan Bhaskar 《International Journal of Wireless Information Networks》2008,15(1):53-60
This paper analyzes the distribution and density functions of the probability of error for Rayleigh and Rician fading channels
with diversity. An expression for the signal-to-noise ratio is derived for an asynchronous CDMA (A-CDMA) system with diversity.
The error probability distribution and density functions are derived and plotted for different mean energy-to-noise ratios.
相似文献
Vidhyacharan BhaskarEmail: |
2.
In this paper, a closed-form expression for the probability of error in a coherent BPSK system over Generalized Rayleigh fading
channels is derived. An L-branch equal gain combining diversity scheme is used. Theoretical results for the probability of error are plotted for various
values of the number of degrees of freedom (n) and diversity order (L). A simulation is performed and the simulated results are found to match very well with the theoretical results.
相似文献
Vidhyacharan BhaskarEmail: |
3.
In this work the performance of a Fractional Fourier transform (FrFT) based Minimum Mean Squared Error receiver for MIMO systems
with space time processing over Rayleigh faded channels is presented. The proposed receiver called Optimum FrFT based MIMO
receiver (OFMR) shows improved performance outperforming the simple MMSE receiver in Rayleigh faded channel.
相似文献
Rajesh KhannaEmail: Email: |
4.
Xianyi Rui 《Wireless Personal Communications》2009,50(2):133-142
The effect of co-channel interference (CCI) is considered in multiple-input multiple-output (MIMO) systems employing maximal
ratio combining (MRC) under independent and identically distributed Rayleigh fading. Closed-form capacity and symbol error
rate expressions are presented to evaluate the performance without any numerical integrations or statistical simulations.
The analytical results are compared with Monte Carlo simulations and the good agreement is obtained.
相似文献
Xianyi RuiEmail: |
5.
Cognitive Radio with Single Carrier TDCS and Multicarrier OFDM Approach with V-BLAST Receiver in Rayleigh Fading Channel 总被引:1,自引:0,他引:1
This article presents the performance comparison of TDCS and OFDM based cognitive radio for MIMO system using VBLAST receiver
architecture to reconstruct the transmitted data. The interference avoidance performance in terms of BER and bitrate are improved
by adding multiple antennas to the system and the use of V-BLAST technique at the receiver. The results show the most promising
interference avoidance technique combined with MIMO V-BLAST architecture to be applied in the CR system.
相似文献
L. P. LigthartEmail: |
6.
Saralees Nadarajah 《Wireless Personal Communications》2009,49(4):575-585
The quantization error for MIMO (multiple-input multiple-output) downlink channels is known to be the minimum of independent
and identically distributed beta random variables. In this note, an exact expression is derived for the average quantization
error. Computational issues relating to its correctness, usage and approximations are discussed.
相似文献
Saralees NadarajahEmail: |
7.
In this paper we proposed the results of average LCR (level crossing rate) and AFD (average fading duration) criterions applied
to evaluate the performance of dual-branch SC (selection combining) reception in the specified fading channels characterized
as statistical distributions with correlated-Rayleigh and correlated-Rice models. Moreover, in order to unify and clarify
the criterions of performance formulas with average LCR and AFD for SC diversity over different kinds of fading models, include
such as Rayleigh, Rice, Nakagami-m, and Weibull distributions etc., almost all of the ever researched and published results from discussing about the LCR and
AFD of SC diversity are comprehensively collected in this report. On the other hand, for the purpose of comparison, there
are a large number of LCR and AFD performance formulas for SC diversity and the generalized fading statistic models are extracted
and tabulated together, in which the cases of correlated and independent proprieties between diversity branches are taken
into consideration too (some of the formulas are illustrated by the assumption of dual-branch SC diversity).
相似文献
Joy Iong-Zong ChenEmail: |
8.
Vidhyacharan Bhaskar 《International Journal of Wireless Information Networks》2007,14(4):237-250
This paper formulates a finite-state Markov channel model to represent received signal-to-noise (SNR) ratios having lognormal,
K-distribution, chi-square (central) and chi-square (non-central) distributions in a slow fading channel. The range of the
SNRs is partitioned into a finite number of states following earlier works in literature. Performance measures like level
crossing rates, steady-state probabilities, transition probabilities, and state-time durations are derived, and numerical
results are plotted and discussed for the FSMC models for all the distributions.
相似文献
Vidhyacharan BhaskarEmail: |
9.
Elliptic curve cryptography (ECC) is recognized as a fast cryptography system and has many applications in security systems.
In this paper, a novel sharing scheme is proposed to significantly reduce the number of field multiplications and the usage
of lookup tables, providing high speed operations for both hardware and software realizations.
相似文献
Brian KingEmail: |
10.
Grzegorz Mrugalski Janusz Rajski Chen Wang Artur Pogiel Jerzy Tyszer 《Journal of Electronic Testing》2007,23(1):35-45
This paper describes a non-recursive fault diagnosis technique for scan-based designs with convolutional test response compaction.
The proposed approach allows a time-efficient and accurate identification of failing scan cells using Gauss–Jordan elimination
method.
相似文献
Jerzy Tyszer (Corresponding author)Email: |
11.
Physical fading radio channels encountered in wireless mobile communication are often modeled as a complex Gaussian process
whose envelope is statistically described by Rayleigh or Rician probability distribution function (PDF). In most of the literature,
the accuracy of the simulation model is estimated by comparing the simulated autocorrelation function (ACF) of inphase (or
quadrature phase) component of the fading process and ACF of squared envelope with the analytical ones. In this paper, we
examine the performance of a sum of sinusoid (SOS) based Rician fading channel simulator on the basis of the ACF and power
spectral density (PSD) of the fading envelope. We obtained simplified approximate expressions for the autocorrelation and
mean value of the fading envelope which become more accurate as the value of Rice factor increases. In the simulation, the
line-of-sight (LOS) component is modeled as a zero-mean random variable with pre-chosen angle of arrival (AOA) and random initial phase. We showed that the AOA of the LOS component
significantly affects the level crossing rate (LCR) and average fade duration (AFD) of the fading envelope. All simulation
results are compared with the analytical results and a very good agreement between them is found.
相似文献
Rekha Gupta (Corresponding author)Email: |
12.
The paper summarizes the main results of one of the key panel session of the Workshop, focused on the investigation about
the possible translation of the “layerless communications” from a dreaming vision to reality.
相似文献
Juha SaarnioEmail: |
13.
For applications requiring a large dynamic, real numbers may be represented either in floating-point, or in the logarithm
number system (LNS). Which system is best for a given application is difficult to know in advance, because the cost and performance
of LNS operators depend on the target accuracy in a highly non linear way. Therefore, a comparison of the pros and cons of
both number systems in terms of cost, performance and overall accuracy is only relevant on a per-application basis. To make
such a comparison possible, two concurrent libraries of parameterized arithmetic operators, targeting recent field-programmable
gate arrays, are presented. They are unbiased in the sense that they strive to reflect the state-of-the-art for both number
systems. These libraries are freely available at .
相似文献
Jérémie Detrey (Corresponding author)Email: |
Florent de DinechinEmail: |
14.
Vidhyacharan Bhaskar 《International Journal of Wireless Information Networks》2007,14(3):191-203
In this paper, closed-form expressions for the capacities per unit bandwidth for Generalized Rayleigh fading channels are
derived for optimal power adaptation, constant transmit power, channel inversion with fixed rate, and truncated channel inversion
adaptation policies. The closed-form solutions are derived for the single antenna reception (without diversity combining)
and MRC diversity reception cases. Optimal power adaptation policy provides the highest capacity over the other adaptation
policies both with and without diversity combining. Truncated channel inversion policy suffers a large capacity penalty relative
to the optimal power adaptation policy as the number of degrees of freedom is increased. However, with increase in diversity,
the capacity penalty for the truncated channel inversion policy decreases. Capacity gains are more prominent for channel inversion
with fixed rate policy as compared to the other adaptation policies.
相似文献
Vidhyacharan BhaskarEmail: |
15.
This paper presents an adaptive multiuser channel estimator using the reduced-Kalman least-mean-square (RK-LMS) algorithm.
The frequency-selective fading channel is modeled as a tapped-delay-line filter with smoothly time-varying Rayleigh distributed
tap coefficients. The multiuser channel estimator based on minimum-mean-square-error (MMSE) criterion is used to predict the
filter coefficients. We also present its convergence characteristics and tracking performance using the RK-LMS algorithm.
Unlike the previously available Kalman filtering algorithm based approach (Chen, Chen IEEE Trans Signal Process 49(7): 1523–1532, 2001) the incorporation of RK-LMS algorithm reduces the computational complexity of multiuser channel estimator
used in the code division multiple access wireless systems. The computer simulation results are presented to demonstrate the
substantial improvement in its tracking performance under the smoothly time-varying environment.
相似文献
D. K. MehraEmail: |
16.
This paper presents a novel methodology for capturing the coupling between the different cells in both the uplink and downlink
directions in a Wideband Code Division Multiple Access (WCDMA) scenario. It is based on the definition and computation of
the gradient of the uplink cell load factor and the downlink transmitted power, which are the two main parameters that reflect
the actual cell load in the two link directions. The paper shows that the gradient is able to capture the relevant information
about the spatial distribution of traffic, which has an impact on cell performance. The proposed methodology is also used
as the basis for defining and evaluating new Radio Resource Management (RRM) strategies that operate at a multi-cell level.
相似文献
Ramon AgustíEmail: |
17.
A. Pérez-Pascual T. Sansaloni V. Torres V. Almenar J. Valls 《Journal of Signal Processing Systems》2009,56(1):35-40
This paper shows that when a digital receiver is designed utilizing two clock scopes, the digital down-converter can be designed
to be efficient in terms of area and power consumption. The main design parameter that contributes to make the design efficient
is the relationship between the transition band of the designed filter and its sampling frequency.
相似文献
J. VallsEmail: |
18.
To support distributive tracking of moving targets in a wireless sensor network, sensors that receive signal from the same
target must collaborate to facilitate collaborative, distributed target tracking. We present an efficient dynamic sensor self-organizing
algorithm that clusters sensors into groups without requiring a centralized control. Extensive simulations are conducted to
verify the performance improvement as well as the communication reduction for the proposed methods.
相似文献
Xiaohong ShengEmail: |
19.
A New Routing Metric for Satisfying Both Energy and Delay Constraints in Wireless Sensor Networks 总被引:1,自引:0,他引:1
Besides energy constraint, wireless sensor networks should also be able to provide bounded communication delay when they are
used to support real-time applications. In this paper, a new routing metric is proposed. It takes into account both energy
and delay constraints. It can be used in AODV. By mathematical analysis and simulations, we have shown the efficiency of this
new routing metric.
相似文献
YeQiong SongEmail: |
20.
Chee Kyun Ng Nor Kamariah Noordin Sabira Khatun Borhanuddin Mohd Ali Sudhanshu Shekhar Jamuar Mahamod Ismail 《Wireless Personal Communications》2008,46(3):305-316
The performance of code division multiple access (CDMA) systems can be affected by small scale fading such as Rayleigh fading
channel. In this paper, the application of smart antenna and Large Area Synchronous CDMA (LAS CDMA) systems, which introduce
directional diversity channel, is presented. A novel interference cancellation scheme through dynamic space code (DSC) algorithm
is briefly described. The directional diversity can be realized from the directional gain of smart antenna system. It can
be found that when the number of elements in smart antenna is increase the directional gain of antenna system is much higher
than single antenna. The system performance analysis in term of error probability is compared between traditional and LAS
CDMA systems in both single and smart antenna systems. From the performance analysis it is found that CDMA system is more
susceptible to multipath fading channel than interferences from existing users.
相似文献
Mahamod IsmailEmail: |