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Articles 1 - 5 of 5
Full-Text Articles in Engineering
Comments On "Timing Estimation And Resynchronization For Amplify-And-Forward Communication Systems”, Hani Mehrpouyan, Steven D. Blostein
Comments On "Timing Estimation And Resynchronization For Amplify-And-Forward Communication Systems”, Hani Mehrpouyan, Steven D. Blostein
Hani Mehrpouyan
This correspondence first shows that the Cramer-Rao lower bound (CRLB) derivations in the above paper are incorrect. In addition, contrary to the claims in the above paper, the assumptions of perfect timing offset estimation and matched-filtering at the relays affect the generality of the analytical results and cannot be justified assumption.
Bounds And Algorithms For Multiple Frequency Offset Estimation In Cooperative Networks, Hani Mehrpouyan, Steven D. Blostein
Bounds And Algorithms For Multiple Frequency Offset Estimation In Cooperative Networks, Hani Mehrpouyan, Steven D. Blostein
Hani Mehrpouyan
The distributed nature of cooperative networks may result in multiple carrier frequency offsets (CFOs), which make the channels time varying and overshadow the diversity gains promised by collaborative communications. This paper seeks to address multiple CFO estimation using training sequences in space-division multiple access (SDMA) cooperative networks. The system model and CFO estimation problem for cases of both decode-and-forward (DF) and amplify-and-forward (AF) relaying are formulated and new closed-form expressions for the Cramer-Rao lower bound (CRLB) for both protocols are derived. The CRLBs are then applied in a novel way to formulate training sequence design guidelines and determine the effect …
On Models, Bounds, And Estimation Algorithms For Time-Varying Phase Noise, M. Reza Khanzadi, Hani Mehrpouyan, Erik Alpman, Tommy Svensson, Dan Kuylenstierna, Thomas Eriksson
On Models, Bounds, And Estimation Algorithms For Time-Varying Phase Noise, M. Reza Khanzadi, Hani Mehrpouyan, Erik Alpman, Tommy Svensson, Dan Kuylenstierna, Thomas Eriksson
Hani Mehrpouyan
In this paper, a new discrete-time model of phase noise for digital communication systems, based on a comprehensive continuous-time representation of time-varying phase noise is derived and its statistical characteristics are presented. The proposed phase noise model is shown to be more accurate than the classical Wiener model. Next, using the proposed discrete-time model, the non-data-aided (NDA) and decision-directed (DD) maximum-likelihood (ML) estimators of time-varying phase noise are derived. To evaluate the performance of the proposed estimators, the Cramér-Rao lower bound (CRLB) for each estimation approach is derived and by using Monte-Carlo simulations it is shown that the mean-square error …
A New Distributed Approach For Achieving Clock Synchronization In Heterogeneous Networks, Hani Mehrpouyan, Steven D. Blostein, Tommy Svensson
A New Distributed Approach For Achieving Clock Synchronization In Heterogeneous Networks, Hani Mehrpouyan, Steven D. Blostein, Tommy Svensson
Hani Mehrpouyan
Heterogeneous networks have the potential to improve coverage, throughput, and energy efficiency of wireless networks through the use of specialized cellular structures, in particular femtocells and macrocells. However, to reduce interference between different cells, ensure smooth hand-offs from cell to cell, and achieve seamless operation the overall network needs to be synchronized. In this paper a new distributed clock synchronization scheme for heterogeneous networks is proposed that employs the clock drift information available at user-equipments (UEs) to achieve synchronization between non-interacting femtocells and macrocells. Simulation results show that the proposed scheme can significantly reduce the clock drift between macrocells and …
Optimal And Approximate Methods For Detection Of Uncoded Data With Carrier Phase Noise, Rajet Krishnan, Hani Mehrpouyan, Thomas Eriksson, Tommy Svensson
Optimal And Approximate Methods For Detection Of Uncoded Data With Carrier Phase Noise, Rajet Krishnan, Hani Mehrpouyan, Thomas Eriksson, Tommy Svensson
Hani Mehrpouyan
Previous results in the literature have shown that derivation of the optimum maximum-likelihood (ML) receiver for symbol-by-symbol (SBS) detection of an uncoded data sequence in the presence of random phase noise is an intractable problem, since it involves the computation of the conditional probability distribution function (PDF) of the phase noise process. In this paper, we seek to minimize symbol error probability (SEP), which is achieved by SBS detection of the sequence based on all received signals. We show that the ML detector for this problem can be formulated as a weighted sum of central moments of the conditional PDF …