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Communications, IEEE Transactions on

Issue 10 • Date October 2008

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Displaying Results 1 - 25 of 26
  • Table of contents

    Publication Year: 2008 , Page(s): i - ii
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    Freely Available from IEEE
  • BICM-ID with signal space diversity over cascaded rayleigh fading channels [transactions letters]

    Publication Year: 2008 , Page(s): 1561 - 1568
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (377 KB) |  | HTML iconHTML  

    Bit-interleaved coded modulation with iterative decoding (BICM-ID) using signal space diversity (SSD) is considered for cascaded Rayleigh fading channels. A tight bound on the asymptotic error probability is derived to determine the optimal rotation matrix for SSD design and to identify the key parameters that influence the system performance. It is shown that, for small modulation constellation, a cascaded Rayleigh fading causes a much more severe performance degradation than a conventional Rayleigh fading. However, BICM-ID employing SSD with a sufficiently large constellation can close the performance gap between the conventional and cascaded Rayleigh fading channels, and their performance can closely approach that over an AWGN channel. Illustrative simulation results for various scenarios are in a good agreement with analytical derivations. View full abstract»

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  • Two algorithms for soft-decision decoding of reed-solomon codes, with application to multilevel coded modulations

    Publication Year: 2008 , Page(s): 1569 - 1574
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (227 KB) |  | HTML iconHTML  

    In this paper two symbol-level soft-decision decoding algorithms for Reed-Solomon codes, derived form the ordered statistics (OS) and from the generalized minimum-distance (GMD) decoding methods, are presented and analyzed. Both the OS and the GMD algorithms are based on the idea of producing a list of candidate code words, among which the one having the larger likelihood is selected as output. We propose variants of the mentioned algorithms that allow to finely tune the size of the list in order to obtain the desired decoding complexity. The method proposed by Agrawal and Vardy for computing the error probability of the GMD algorithm is extended to our decoding methods. Examples are presented where these algorithms are applied to singly-extended Reed-Solomon codes over GF(16) used as outer codes in a 128-dimensional coded modulation scheme that attains good performance, with manageable decoding complexity. View full abstract»

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  • Iterative reduced-search decoding for coded partial-response channels

    Publication Year: 2008 , Page(s): 1575 - 1580
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (304 KB) |  | HTML iconHTML  

    The full-complexity soft-input/soft-output (SISO) detector based on the BCJR algorithm for coded partial-response channels has a computational complexity growing exponentially with channel memory length. In this letter, we propose a low complexity soft-output channel detector based on the Chase decoding algorithm, which was previously applied to decode turbo product codes. At each iteration, the proposed detector forms a candidate list using all possible combinations of bit patterns in the weakest indices based on tentative hard estimates and a priori information fed back from the outer decoder. To demonstrate the performance/complexity tradeoff of the proposed detector, simulation results over rate-8/9 turbo-coded EPR4 and ME/sup 2/PR4 channels are presented, respectively. It is shown that the proposed detector can significantly reduce the computational complexity with only a small performance loss compared to the BCJR algorithm. View full abstract»

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  • A distortion optimal rate allocation algorithm for transmission of embedded bitstreams over noisy channels

    Publication Year: 2008 , Page(s): 1581 - 1584
    Cited by:  Papers (7)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (233 KB) |  | HTML iconHTML  

    We propose a distortion optimal rate allocation algorithm for robust transmission of embedded bitstreams over noisy channels. The algorithm is based on the backward application of a Viterbi-like algorithm to a search trellis, and can be applied to both scenarios of fixed and variable channel packet length problems, referred to as FPP and VPP, respectively. For the VPP, the complexity of the algorithm is comparable to the well-known dynamic programming approach of Chande and Farvardin. For the FPP, where no low-complexity algorithm is known, the complexity of the proposed algorithm is O(N/sup 2/), where N is the number of transmitted packets. View full abstract»

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  • Construction and characteristics of codewords and pulse shapes that satisfy spectral constraints

    Publication Year: 2008 , Page(s): 1585 - 1590
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (303 KB) |  | HTML iconHTML  

    Constrained sequence codes and pulse shapes are used to control signal characteristics in digital communication systems. This letter outlines a technique to construct codewords and pulse shapes to meet specified spectral constraints. Based on a block-coded representation of the signal, it is shown how symbol values can be evaluated to satisfy the most significant terms of a Fourier series representation of the desired spectral response. Several properties of the resulting signals are given, and examples are presented to confirm the validity of this approach. View full abstract»

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  • Call admission control strategy for system throughput maximization considering both call- and packet-level QoSs

    Publication Year: 2008 , Page(s): 1591 - 1595
    Cited by:  Papers (2)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (370 KB) |  | HTML iconHTML  

    This letter presents a call admission control (CAC) strategy for system throughput maximization in wireless uplink systems. This strategy considers not only the call-level quality of service (QoS) (i.e., blocking probability) but also the packet-level QoS (i.e., outage probability). Using the statistical co-channel interference (CCI) model and state diagram, the outage probability and the blocking probability are investigated as a function of the relative traffic load. We formulate the CAC strategy problem based on relative traffic load, and suggest a solution. The numerical results show that maximum system throughput can be achieved by controlling the relative traffic load. In addition, we illustrate the region where system throughput is constrained by call- and packet-level QoSs. This examination shows that the call and packet-level QoSs must be considered together to achieve maximum system throughput. View full abstract»

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  • Multiple-symbol differential detection based on combinatorial geometry

    Publication Year: 2008 , Page(s): 1596 - 1600
    Cited by:  Papers (6)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (240 KB) |  | HTML iconHTML  

    In this paper, the application of combinatorial geometry to noncoherent multiple-symbol differential detection (MSDD) is considered. The resulting algorithm is referred to as CG-MSDD. Analytical expressions for the complexity of CG-MSDD are derived and it is shown that it is polynomial in the length N of the MSDD observation window if the rank of the N times N channel autocorrelation matrix is fixed, but in fact exponential in N if standard fading models are considered. Compared to popular sphere-decoder based MSDD, CG-MSDD is superior (i) in low-signal-to-noise power ratio (SNR) slow-fading channels as its complexity is independent of the SNR, (ii) as its complexity is constant, i.e., independent of the particular channel and noise realization, and (iii) asymptotically, as its complexity exponent only scales linearly with the bandwidth of the fading process. View full abstract»

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  • Significance in adding a queuing subsystem to the R/sup 3/T random access OCDMA protocol

    Publication Year: 2008 , Page(s): 1601 - 1605
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (364 KB) |  | HTML iconHTML  

    A queuing subsystem is proposed to the round robin receiver/transmitter (R3T) optical code-division multiple-access (OCDMA) protocol. The corresponding state diagram and its mathematical model are outlined. We prove that significant improvement in terms of system throughput and blocking probability can be achieved by only adding a single buffer at each user node. Furthermore, the modified R3T protocol can support higher traffic loads with acceptable delay and good efficiency. View full abstract»

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  • Performance analysis on an MAP fine timing algorithm in UWB multiband OFDM

    Publication Year: 2008 , Page(s): 1606 - 1611
    Cited by:  Papers (5)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (478 KB) |  | HTML iconHTML  

    In this paper we develop a fine synchronization algorithm for multiband OFDM transmission in the presence of frequency selective channels. This algorithm is based on maximum a posteriori (MAP) joint timing and channel estimation that incorporates channel statistical information, leading to considerable performance enhancement relative to existing maximum likelihood (ML) approaches. We carry out a thorough performance analysis of the fine timing algorithm, and link the diversity concept widely used in data communications to the timing performance. We show that the probability of the timing offset equal to or larger than Delta taps has a diversity order of NB min(Delta, L) in Rayleigh fading channels, where NB is the number of subbands and L is the number of channel taps. This result reveals that the timing estimate is very much concentrated around the true timing as the signal to noise ratio (SNR) increases. Our simulations confirm the theoretical analysis, and also demonstrate the robustness of the proposed timing algorithm against model mismatches in a realistic UWB indoor channel. View full abstract»

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  • Optimal diversity combining based on linear estimation of rician fading channels

    Publication Year: 2008 , Page(s): 1612 - 1615
    Cited by:  Papers (7)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (292 KB) |  | HTML iconHTML  

    Optimal receiver diversity combining employing linear channel estimation is examined. Based on the statistical properties of least-squares (LS) and minimum mean square error (MMSE) channel estimation, an optimal diversity receiver for wireless systems employing practical linear channel estimation on Rician fading channels is proposed. The new receiver structure includes the conventional maximal ratio combining receiver as a special case. Exact analytical expressions for the symbol error rates (SERs) of LS and MMSE channel estimation aided optimal diversity combining are derived. It is shown that, if an optimal detector is used, an MPSK wireless system with MMSE channel estimation has the same SER when the MMSE channel estimation is replaced by LS estimation. This is an interesting counterexample to the common perception that channel estimation with smaller mean square error leads to smaller SER. Extensive simulation results validate the theoretical results. View full abstract»

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  • Further results on noncoherent block-coded MPSK [transactions papers]

    Publication Year: 2008 , Page(s): 1616 - 1625
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (557 KB) |  | HTML iconHTML  

    A novel noncoherent block coding scheme, called noncoherent block-coded MPSK (NBC-MPSK), was proposed recently. In this paper, we present further research results on NBC-MPSK. We first focus on the rotational invariance (RI) of NBC-MPSK. Based on the RI property of NBC-MPSK with multistage decoding, a noncoherent near-optimal linear complexity multistage decoder for NBC-MPSK is proposed. Then we investigate a tree-search ML decoding algorithm for NBCMPSK. The derived algorithm is shown to have low complexity and excellent error performance. In this paper, we also utilize the idea of the NBC-MPSK to design noncoherent space-time block codes, called noncoherent space-time block-coded MPSK (NSTBC-MPSK). For two transmit antennas, we propose a signal set with set partitioning and derive the minimum noncohent distance of NSTBC-MPSK with this signal set. For the decoding of NSTBC-MPSK, we modify the ML decoding algorithm of NBC-MPSK and propose an iterative hard-decision decoding algorithm. Compared with training codes and unitary space-time modulation, NBC-MPSK and NSTBC-MPSK have larger minimum noncoherent distance and thus better error performance for the noncoherent ML decoder. View full abstract»

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  • Design of regular (2,d/sub c/)-LDPC codes over GF(q) using their binary images

    Publication Year: 2008 , Page(s): 1626 - 1635
    Cited by:  Papers (88)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (437 KB) |  | HTML iconHTML  

    In this paper, a method to design regular (2, dc)- LDPC codes over GF(q) with both good waterfall and error floor properties is presented, based on the algebraic properties of their binary image. First, the algebraic properties of rows of the parity check matrix H associated with a code are characterized and optimized to improve the waterfall. Then the algebraic properties of cycles and stopping sets associated with the underlying Tanner graph are studied and linked to the global binary minimum distance of the code. Finally, simulations are presented to illustrate the excellent performance of the designed codes. View full abstract»

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  • Universal serially concatenated trellis coded modulation for space-time channels

    Publication Year: 2008 , Page(s): 1636 - 1646
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (402 KB) |  | HTML iconHTML  

    This paper presents serially concatenated trellis coded modulations (SCTCMs) that perform consistently close to the available mutual information for periodic erasure channel (PEC), periodic fading channel (PFC) and the 2 times 2 compound matrix channel. We use both the maximum-likelihood decoding criteria and iterative decoding criteria to design universal SCTCMs for the PEC and the PFC. For the space-time channel, by demultiplexing the symbols across the antennas, the proposed universal SCTCMs for the period-2 PFC deliver consistent performance over the eigenvalue skew of the matrix channel. Within the family of channels having the same eigenvalue skew, a time-varying linear transformation (TVLT) is used to mitigate the performance variation over different eigenvectors. The proposed space-time SCTCMs of 1.0, 2.0 and 3.0 bits per transmission require excess mutual information in the ranges 0.11-0.15, 0.23- 0.26 and 0.35-0.53 bits per antenna, respectively. Because of their consistent performance over all channels, the proposed codes will have good frame-error-rate (FER) performance over any quasi-static fading distribution. In particular, the codes provide competitive FER performance in quasi-static Rayleigh fading. View full abstract»

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  • Transmit beamforming for space-frequency coded MIMO-OFDM systems with spatial correlation feedback

    Publication Year: 2008 , Page(s): 1647 - 1655
    Cited by:  Papers (6)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (384 KB) |  | HTML iconHTML  

    This paper addresses the problem of joint optimization of transmit beamforming and space-frequency (SF) coding for MIMO-OFDM systems with spatial correlation feedback in broadband communications. This problem is challenging in the sense that the transmitter should be designed to beamform across multiple eigenspaces associated with the multipath environment simultaneously. With arbitrary transmit spatial correlation, the performance analysis for SF-coded MIMO-OFDM systems with beamforming is provided, and a general optimization problem for the beamforming design is formulated. Three suboptimal approaches to design the beamformer based on the derived design criteria are proposed: i) eigenvalue selection scheme; ii) eigenspace selection scheme; and iii) per-subcarrier approach based on decoding at each subcarrier. The proposed schemes take into account the multiple eigenspace information associated with the multipath-delay channel. Improvement in the performance over SF coding without beamforming is shown through simulations in terms of bit error rate. The eigenvalue selection scheme provides the best performance among the proposed algorithms. This scheme locates the subspace associated with the largest eigenvalues in the eigenspace of the covariance matrices. With the eigenvalue selection scheme, the performance improvement is about 3 dB over the SF coding without beamforming for highly correlated channels as shown in our simulations. View full abstract»

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  • On the design of uplink and downlink group-orthogonal multicarrier wireless systems

    Publication Year: 2008 , Page(s): 1656 - 1665
    Cited by:  Papers (12)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (488 KB) |  | HTML iconHTML  

    Group-orthogonal multicarrier code-division multiple access (GO-MC-CDMA) has been proposed as an attractive multiplexing technique for the uplink segment of wireless systems. More recently, a variant of this scheme has also been proposed for the downlink. This paper presents a unified bit error rate (BER) performance analysis of group-orthogonal wireless systems when using maximum likelihood (ML) multiuser/multisymbol detection covering both link directions. Valuable design rules regarding the number of subcarriers per group and the selection of spreading codes are derived. Simulations results using realistic system parameters and ETSI BRAN channel models are also presented which serve to validate the analytical results. View full abstract»

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  • P-order metric UWB receiver structures with superior performance

    Publication Year: 2008 , Page(s): 1666 - 1676
    Cited by:  Papers (20)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (600 KB) |  | HTML iconHTML  

    The generalized Gaussian probability density function is shown to better approximate the probability density function of the multiple access interference in ultra-wide bandwidth systems than the Gaussian approximation and the Laplacian density approximation. Two ultra-wide bandwidth receiver structures based on this new approximation using a p-order metric receiver decision statistic are investigated for the detection of time-hopping ultra-wide bandwidth wireless signals in multiple access interference channels. The first receiver outperforms both the conventional matched filter ultra-wide bandwidth receiver and the soft-limiting ultra-wide bandwidth receiver when only multiple access interference is present in UWB channels. The second new receiver with adaptive limiting threshold outperforms the conventional matched filter ultra-wide bandwidth receiver, the soft-limiting ultra-wide bandwidth receiver, and the adaptive threshold soft limiting ultra-wide bandwidth receiver in all multiple access interference-plus-noise environments. In multipath channels, a new Rake receiver based on the p-order metric receiver is proposed for signal detection. Mathematical analysis and numerical results show that this new Rake receiver can achieve larger signal-to-interference-plus-noise ratio than the standard matched filter Rake receiver when multipath components are resolvable in UWB channels. View full abstract»

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  • Specifying receiver IP2 and IP3 based on tolerance to modulated blockers

    Publication Year: 2008 , Page(s): 1677 - 1682
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (465 KB) |  | HTML iconHTML  

    This paper provides an analysis of the impact of amplitude modulated blocking signals on receiver performance due to device nonlinearity. Using a standard polynomial model of nonlinearity, we derive limitations on the receiver SNR capabilities, depending on the blocking signal modulation statistical properties. The phenomena that we focus on are cross-modulation due to odd-order nonlinearity and amplitude demodulation due to even-order nonlinearity. The results are then detailed for two types of blocking signal modulations: GSM/EDGE modified 8PSK and UTRA/FDD uplink HPSK. View full abstract»

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  • Differentiated rate scheduling for the down-link of cellular systems

    Publication Year: 2008 , Page(s): 1683 - 1693
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (504 KB) |  | HTML iconHTML  

    We consider the problem of differentiated rate scheduling for the downlink (i.e., multi-antenna broadcast channel), in the sense that the rates required by different users must satisfy certain constraints on their ratios. When full channel state information (CSI) is available at the transmitter and receivers, the problem can be readily solved using dirty paper coding (DPC) and the application of convex optimization techniques on the dual problem which is the multiple access channel (MAC). Since in many practical application full CSI may not be feasible and computational complexity prohibitive when the number of users is large, we focus on other simple schemes that require very little CSI: time-division opportunistic (TO) beamforming where in different time slots (of different lengths) the transmitter performs opportunistic beamforming to the users requiring the same rate, and weighted opportunistic (WO) beamforming where the random beams are assigned to those users having the largest weighted SINR. For single antenna systems we also look at the capacity-achieving superposition coding (SC) scheme. In all cases, we determine explicit schedules to guarantee the rate constraints and show that, in the limit of large number of users, the throughput loss compared to the unconstrained throughput (sum-rate capacity) tends to zero. We further provide bounds on the rate of convergence of the sum-rates of these schemes to the sum-rate capacity. Finally, we provide simulation results of the performance of different scheduling schemes considered in the paper. View full abstract»

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  • Priority-based offline wavelength assignment in OBS networks

    Publication Year: 2008 , Page(s): 1694 - 1704
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (553 KB) |  | HTML iconHTML  

    Optical burst switching (OBS) is a promising technique for wavelength division multiplexing (WDM) networks. In practice, wavelength converters (WCs) are either absent or only sparsely deployed in WDM networks due to economic and technical limitations. Thus, wavelength assignment is expected to be an important component of OBS networks. In this paper, an offline wavelength assignment scheme in OBS networks without wavelength conversion capability is proposed. The key idea of the scheme is to decide the wavelength searching order of each traffic connection at edge nodes according to the wavelength priorities determined by the calculated burst loss probabilities on different wavelengths. Simulation results indicate that the proposed scheme can reduce the network-wide burst loss probability significantly compared with other schemes. It is also illustrated that the performance of the proposed scheme can be further enhanced by a larger number of wavelengths per link and a reasonable delay bound at edge nodes. View full abstract»

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  • Cross-layer network planning for multi-radio multi-channel cognitive wireless networks

    Publication Year: 2008 , Page(s): 1705 - 1714
    Cited by:  Papers (13)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (475 KB) |  | HTML iconHTML  

    We propose a general network planning framework for multi-radio multi-channel wireless networks. Under this framework, data routing, resource allocation, and scheduling are jointly designed to maximize a network utility function. We first treat such a cross-layer design problem with fixed radio distributions across the nodes and formulate it as a large-scale convex optimization problem. A primal-dual method together with the column-generation technique is proposed to efficiently solve this problem. We then consider the radio allocation problem, i.e., the optimal placement of radios within the network to maximize the network utility function. This problem is formulated as a large- scale combinatorial optimization problem. We derive the necessary conditions that the optimal solution should satisfy, and then develop a sequential optimization scheme to solve this problem. Simulation studies are carried out to assess the performance of the proposed cross-layer network planning framework. It is seen that the proposed approach can significantly enhance the overall network performance. View full abstract»

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  • An accurate analytical model on blocking performance of multicast three-stage networks

    Publication Year: 2008 , Page(s): 1715 - 1721
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (270 KB) |  | HTML iconHTML  

    The fast deployment of broadband networks and the evolution of communication services has revealed the importance of a network-wide availability of multicast communications, that is from one source to multiple destinations. This paper considers three-stage switching networks able to support multicast traffic, i.e. connections in which one inlet of a node is connected to more than one outlet of the node at the same time. An analytical model is developed here that evaluates the blocking probability of multicast connections taking into account statistically the correlation between occupancy events in links belonging to different interstage patterns. Such new model proves to be more accurate than any previous model addressing the same issue. Interestingly enough, unlike other models the new formulation is consistent with the theoretical conditions of a non-blocking three-stage switching network. View full abstract»

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  • Comparison of different feedback signals used in one stage PMD compensators for different modulation formats

    Publication Year: 2008 , Page(s): 1722 - 1728
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (459 KB) |  | HTML iconHTML  

    As PMD compensation has become a very intense subject of research in recent years, the achievement of simple PMD compensators based on a feedback signal is a key issue. As PMD compensation uses a feedback indicator for system performance evaluation, such feedback signals must reproduce the DGD variations with time. In this paper, the correlation between DGD and different feedback signals is studied with a new method. This method is applied for various modulation schemes, leading to well-known results. By applying the method to the electrical and optical duobinary formats, it is shown that for duobinary signals, the DOP feedback signal shows the best correlation with instantaneous DGD value. Such a behavior of duobinary format is very interesting since duobinary modulation schemes are now considered for systems upgrades or mixed architectures (10 Gbit/s-40 Gbit/s on the same link). In such systems, PMD compensation has to be bit-rate independent which is available with the DOP as feedback indicator. View full abstract»

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  • Iterative symbol timing recovery for short burst transmission schemes

    Publication Year: 2008 , Page(s): 1729 - 1736
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (832 KB) |  | HTML iconHTML  

    This paper presents a novel iterative symbol timing recovery (STR) scheme for short burst transmission formats, a paradigm commonly found in modern wireless systems, like, for instance, time division multiple access (TDMA) schemes and future wireless packet data networks. Both data-aided (DA) and decision-directed (DD) solutions are considered and performance is pursued by means of an iterative burst-by-burst scheme which exploits the Farrow structure for the polynomial interpolation filter. The convergence of the algorithm is discussed according to the expectation maximization (EM) framework. Performance is evaluated by simulating 4-QAM and 16-QAM transceivers and simulations results are compared under different modulation orders and channel conditions, for both the decision-directed and data-aided cases. View full abstract»

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  • Robust and consistent pilot designs for frequency offset estimation in MIMO OFDM systems

    Publication Year: 2008 , Page(s): 1737 - 1747
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (393 KB) |  | HTML iconHTML  

    This paper presents pilot designs for consistent frequency offset estimation of MIMO OFDM systems in frequency selective fading channels. We derive the sufficient consistency condition for the pilots in MIMO OFDM systems to yield unambiguous estimation, and present corresponding consistent pilot designs. We discuss robustness of the frequency offset estimation against outliers at low to moderate SNR values and present an efficient criterion to choose robust and consistent pilots. Furthermore, we develop pilot designs which satisfy both consistency over a limited frequency offset estimation range and the optimal channel estimation condition in MIMO OFDM systems. Simulation results corroborate that both the consistent pilot design condition and the robustness criterion are efficient in choosing pilot patterns yielding better frequency offset estimation performance. View full abstract»

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Aims & Scope

IEEE Transactions on Communications focuses on all telecommunications including telephone, telegraphy, facsimile, and point-to-point television by electromagnetic propagation.

 

 

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Editor-in-Chief
Robert Schober
University of British Columbia