Papers by Abdel Aziz Bassiouni
Estimation of Carrier Frequency Offset (CFO) is the fundamental problem of OFDM systems. CFO can ... more Estimation of Carrier Frequency Offset (CFO) is the fundamental problem of OFDM systems. CFO can be estimated using either time domain or frequency domain methods. A comparative study among different methods of carrier frequency offset estimation in OFDM systems is presented. We consider two techniques in time domain, namely; the Cyclic Prefix (CP) method and the Training Sequence Method. In addition two techniques in frequency domain are considered, namely; Training Symbol method and Pilot Method. Mean square Error (MSE) is the comparison criteria used in the study. Simulation results show that the CFO estimation methods in frequency domain have better performance than CFO estimation methods in time domain, in terms of mean square error (MSE). It is shown that, the pilot tone method outperforms the cyclic prefix method by 7dB and the training sequence with two identical blocks by 10dB. The pilot tone method outperforms the symbol based method by approximately 2dB. The comparison re...
IEEE Communications Letters, 2001
IEEE Communications Letters, 2001
A novel three-dimensional distribution traffic is proposed for Low Earth Orbit (LEO) satellite sy... more A novel three-dimensional distribution traffic is proposed for Low Earth Orbit (LEO) satellite systems. The effect of the traffic geographical nonuniformity on the performance of these satellite systems is discussed.
: The method of successive substitution is shown applicable to solve for the classical minimum di... more : The method of successive substitution is shown applicable to solve for the classical minimum distortion quantizer parameters. The method is self converging and parameters can be calculated to any desired accuracy. The minimum distortion quantizer parameters, as well as parameters based on other criterion such as quantizers for signal detection, minimum risk quantizers and quantizers for LMMS estimation can be solved by Max's trial and error technique. There are also many other approximation methods to calculate the quantizer parameters. This report applies the method of successive substitution and its modifications to solve for the Lloyd-Max quantizer parameters. It is more accurate and computationally more efficient than the previously reported methods. It is shown to easily generate 7 bit (128 level) optimum quantization. The Lloyd-Max minimum mean square distortion quantizer problem deals with transforming a random variable X of differentiable probability density function f...
International journal of engineering research and technology, 2015
Orthogonal frequency division multiplexing (OFDM) systems are very sensitive to the frequency syn... more Orthogonal frequency division multiplexing (OFDM) systems are very sensitive to the frequency synchronization errors in form of carrier frequency offset (CFO). CFO can lead to the Inter-Carrier interference (ICI) and also destroys the orthogonality between sub-carriers. Therefore, CFO plays a key role in Frequency synchronization. Basically for getting a good performance of OFDM, the CFO should be estimated and compensated. In this paper we investigate the algorithms for the CFO estimation in OFDM systems. Four types of estimators are investigated: cyclic prefix (CP) and Training Sequence based estimators in time domain in addition to Training Symbol based and pilot tone based estimators in frequency domain. Mean Square Error (MSE) is the comparison criteria used in studying the performance. Simulation results indicate the performance of the different estimators over both additive white Gaussian noise (AWGN) and four taps multipath fading channels. Keywords—Orthogonal frequency divi...
Wireless Personal Communications, 2002
This paper presents a generalized model of binary phase shift keying (BPSK) direct sequence code ... more This paper presents a generalized model of binary phase shift keying (BPSK) direct sequence code division multiple access (DS/CDMA) macrocellular and microcellular sectorized mobile radio systems over Nakagami fading plus lognormal shadowing channels. RAKE receiver, perfect and imperfect sectorization, voice activity monitoring, microscopic and composite microscopic plus macroscopic diversity are considered. The interrelationships among the number of interfering cells, sectorization
2013 IEEE Global Engineering Education Conference (EDUCON), 2013
ABSTRACT This paper addresses an interdisciplinary approach integrating evaluation of an educatio... more ABSTRACT This paper addresses an interdisciplinary approach integrating evaluation of an educational issue with Artificial Neural Network (ANN) modeling. Specifically, it is concerned with ANN modeling of two Computer Assisted Learning (CAL) packages/modules using various learning rate values. Both packages are considered for teaching a mathematical topic: “How to solve long division problem?”. They have been submitted at the fifth grade classroom level in elementary schools (as a case study with or without associated teacher's voice). Furthermore, after the application of the suggested CAL packages, practical findings have been compared with classical learning obtained results. Interestingly, all findings are shown to be in agreement with simulation results after running the introduced realistic ANN model. Finally, this work investigated well how measured mathematical teaching quality could be fairly improved via assessment of two learning parameters' performance (achievement level & response time).
A new traffic model for Low Earth Orbit (LEO) Satellite system is proposed. Two different cases a... more A new traffic model for Low Earth Orbit (LEO) Satellite system is proposed. Two different cases are considered. The first case represents the situation in which the traffic load follows a bimodal contaminated Gaussian distribution. The second case considers the trimodal distribution. The parameters of this new distribution model are introduced and their effects on the Signal to Interference Ratio (SIR) and the capacity are investigated. KEYWORDS Low Earth Orbit Satellite Communication I. INTRODUCTION Low earth orbit satellite communication systems are one of the most appropriate systems to offer personal communications (PC) [1-3]. They can also provide additional advantages for the global communication networks, e.g., small propagation delay and loss, and high elevation angle in high latitude [4]. One of the most recent candidates for establishing the multiple access in LEO satellite systems is Code Division Multiple Access (COMA). CDMA has higher capacity than TDMA and FDMA if voice activity and frequency reuse by spatial isolation are employed [5]. The non-uniform distribution of the traffic is a normal feature of our globe. However there are only few studies on the effect of this nonuniformity of the traffic on the performance of LEO systems. Performance analysis of
: We consider the problem of detection of known signals in noise using quantized, discrete sensor... more : We consider the problem of detection of known signals in noise using quantized, discrete sensor observations. Optimal design of the quantizers at the sensor sites as well as the global fusion of the quantized observations is presented. Also the equivalence between a team of two sensors and their fusion centre and another team of a primary decision maker and a second opinion is shown. Since the fusion of information is a main pillar of the thesis, an early chapter is devoted to the optimum fusion policy. Extension of the results to the case of vector sensor observations is also considered.
SAE Technical Paper Series, 2007
... Date Published: 2007-08-05. Paper Number: 2007-01-3643. DOI: 10.4271/2007-01-3643. Author(s):... more ... Date Published: 2007-08-05. Paper Number: 2007-01-3643. DOI: 10.4271/2007-01-3643. Author(s): MAA Emam - Helwan Univ. S. Shaaban - Helwan Univ. MA El-Nashar - Helwan Univ. Abdel Aziz M. El-Bassiouni - Cairo University, Egypt. ...
Signal Processing, 1995
The concepts of distributed nonparametric generalized sign and cell averaging (CA) CFAR detection... more The concepts of distributed nonparametric generalized sign and cell averaging (CA) CFAR detection with data fusion have been developed. In both cases L sweeps are assumed to be processed. The local decisions are transmitted from each detector to the fusion center. ...
Menoufia Journal of Electronic Engineering Research
Menoufia Journal of Electronic Engineering Research
IEEE Wireless Communications Letters, 2013
ABSTRACT Orthogonal frequency division multiplexing (OFDM) is sensitive to frequency synchronizat... more ABSTRACT Orthogonal frequency division multiplexing (OFDM) is sensitive to frequency synchronization errors. This letter proposes a novel data-aided carrier frequency offset (CFO) estimator. We show that the eigenvalues of the inter-carrier interference (ICI) coefficient matrix are the elements of a geometric series distributed on the unit circle of the complex plane. Then, we prove that estimating the CFO is equivalent to finding the eigenvalues of a two-dimensional ICI coefficient matrix. As a result, by transmitting the corresponding eigenvectors, an estimate of the CFO value can be found. In addition to its simplicity, the proposed estimator is proven to be a maximum likelihood estimator. Simulation results are presented to demonstrate the high accuracy of the proposed estimator in presence of channel noise and fading.
2009 Fifth International Conference on Wireless and Mobile Communications, 2009
Abstract Orthogonal frequency division multiplexing (OFDM) is sensitive to frequency synchronizat... more Abstract Orthogonal frequency division multiplexing (OFDM) is sensitive to frequency synchronization errors which results in degradation of system performance. Polynomial cancelation coding (PCC) OFDM is introduced to reduce OFDM sensitivity to carrier ...
SAE Technical Paper Series, 2007
... Date Published: 2007-08-05. Paper Number: 2007-01-3643. DOI: 10.4271/2007-01-3643. Author(s):... more ... Date Published: 2007-08-05. Paper Number: 2007-01-3643. DOI: 10.4271/2007-01-3643. Author(s): MAA Emam - Helwan Univ. S. Shaaban - Helwan Univ. MA El-Nashar - Helwan Univ. Abdel Aziz M. El-Bassiouni - Cairo University, Egypt. ...
Signal Processing, 1995
The concepts of distributed nonparametric generalized sign and cell averaging (CA) CFAR detection... more The concepts of distributed nonparametric generalized sign and cell averaging (CA) CFAR detection with data fusion have been developed. In both cases L sweeps are assumed to be processed. The local decisions are transmitted from each detector to the fusion center. ...
IEEE Transactions on Communications, 2000
... R. Esposito, Error probabilities for the Nakagami channel, IEEE Trans. Inform. Theory, vol.... more ... R. Esposito, Error probabilities for the Nakagami channel, IEEE Trans. Inform. Theory, vol. IT-13, pp. 143-148, Jan. 1967. H. Suzuki, A statistical model for urban multipath channels with random delay, IEEE Trans. Commun., vol. COM-25, pp. 673-680, July 1977. U. Charash. ...
—Orthogonal Frequency Division Multiplexing (OFDM) has been considered as a strong candidate for ... more —Orthogonal Frequency Division Multiplexing (OFDM) has been considered as a strong candidate for next generation wireless communication systems. Compared to traditional OFDM, Single Carrier OFDM (SC-OFDM) has demonstrated excellent bit error rate (BER) performance, as well as low peak to average power ratio (PAPR). Similar to other multi-carrier transmission technologies, SC-OFDM suffers significant performance degradation resulting from intercarrier interference (ICI) in high mobility environments. Existing techniques for OFDM can be directly adopted in SC-OFDM to improve performance, however, this improved performance comes at costs such as decreased throughput. In this paper, we analyze the effect of ICI on an SC-OFDM system and propose a novel modulation scheme. The proposed Magnitude-Keyed Modulation (MKM) modulation provides SC-OFDM system immunity to ICI and with an easy implementation it significantly outperforms OFDM, SC-OFDM and MC-CDMA systems with Phase Shift Keying (PSK) modulation and Quadrature Amplitude Modulation (QAM) in severe ICI environment. Analysis also illustrates the proposed SC-OFDM system with MKM modulation maintains low PAPR compared to traditional OFDM and SC-OFDM systems with PSK and QAM modulations. Simulation results for different modulation schemes in various ICI environments confirm the effectiveness of the proposed system.
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Papers by Abdel Aziz Bassiouni