By Topic

Wireless Communications, IEEE Transactions on

Issue 4 • Date April 2009

Filter Results

Displaying Results 1 - 25 of 65
  • Table of contents

    Page(s): i - iii
    Save to Project icon | Request Permissions | PDF file iconPDF (75 KB)  
    Freely Available from IEEE
  • Interference cancellation enhancement through generalized widely linear equalization in QAM systems

    Page(s): 1585 - 1590
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (316 KB) |  | HTML iconHTML  

    In this paper, we introduce a generalized widely linear (WL) equalizer for quadrature amplitude modulation (QAM) systems with single/multiple antennas. In our proposed implementation, the WL receiver first separates the in-phase (I) and quadrature (Q) parts of the complex-valued baseband received signal and jointly filters the two branches for signal detection. Infinite length WL minimum mean-square error (WL-MMSE) linear, and WL decision-feedback-equalizer (WL-DFE) settings are derived and performance is analyzed in co-channel interference limited channels. It is shown that, in frequency selective Rayleigh fading channels, the interference cancellation (IC) gain depends mainly on the rank (r) of the interference correlation matrix (ICM) which is defined as the covariance of the vector-valued signal which consists of the real and imaginary parts of the noise-plus-interference signal collected at multiple antenna branches. Assuming that the DFE feedback path is error free, we show that a WL QAM receiver with N antennas exhibits full IC capability (that is complete interference removal) when the ICM is rank deficient i.e., when: r < 2N. This condition implies that a WL-DFE receiver can reject any combination of M1 pulse-amplitude-modulation (PAM) and M2 QAM interferers satisfying the constraint: M1 + 2M2 < 2N. Simulation results show that, in the presence of PAM-type interference, the gain of WL-DFE is reduced by decision feedback errors while the IC benefit of WL-MMSE is limited by the noise enhancement problem. Nevertheless, the proposed receivers are shown to be useful in cellular systems that employ a combination of PAM and QAM schemes. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Can multiple subchannels improve the delay performance of RTS/CTS-based MAC schemes?

    Page(s): 1591 - 1596
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (232 KB) |  | HTML iconHTML  

    We analyze the delay performance of RTS/CTS-based (Request-To-Send/Clear-To-Send) multi-channel MAC (Medium Access Control) schemes for wireless networks. These schemes usually employ multiple data subchannels for data transmission and one control subchannel to send the RTS/CTS dialogue for channel reservation. Through theoretical analysis and simulations, we show that, in fully-connected networks, such multi-channel MAC schemes suffer longer delays than the corresponding single channel MAC scheme, that puts the RTS/CTS dialogue on the same channel as data packet transmissions. This conclusion holds even when data packets have different priorities and higher priority traffic is sent ahead of lower priority traffic. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A new parameter for UWB indoor channel profile identification

    Page(s): 1597 - 1602
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (237 KB) |  | HTML iconHTML  

    This paper proposes a new parameter for identifying the room typology when the receiver is in ultra wideband (UWB) indoor environments. The method proposed does not imply any estimation process at the received signal. The proposed parameter is not only able to clearly distinguish between line-of-sight (LOS) and non-line-of-sight (NLOS) conditions, but it is also capable of ordering the quality of the received signal in two different LOS or NLOS rooms, although the signal-to-noise-ratio (SNR) is the same. Moreover, this parameter is able to distinguish between LOS and NLOS macro groups clearly and, at the same time, to order conditions within these two macro groups (for example, clear LOS condition from Quasi-LOS, i.e., when an object partially shadows the link, etc.). The method proposed in this paper is based on the calculation of the kurtosis index of the sampled received signal. The kurtosis index can be successfully applied to the received signal in order to identify the typology of the link between transmitter and receiver (LOS, Quasi-LOS, high-NLOS, low-NLOS, extreme-low-NLOS). Results are achieved by both real measurements and simulations with IEEE802.15.3a and 4a channel models. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Welch bound analysis on generic code division multiple access codes with interference free windows

    Page(s): 1603 - 1607
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (222 KB) |  | HTML iconHTML  

    Code-division multiple access (CDMA) technology has been applied to many wireless communication systems. CDMA system suffers from both multiple access interference (MAI) and inter-symbol interference (ISI) over a multipath channel. To suppress MAI and ISI, this paper proposes the spreading codes with interference free windows. In particular, we will develop several upper bounds on the efficiency of generalized spreading codes (for both unitary and complementary codes) in terms of the width of their interference free windows. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Lattice-reduction aided equalization for OFDM systems

    Page(s): 1608 - 1613
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (260 KB) |  | HTML iconHTML  

    Orthogonal frequency division multiplexing (OFDM) is an effective technique to deal with frequency-selective channels since it facilitates low complexity equalization and decoding. Many existing OFDM designs successfully exploit the multipath diversity offered by frequency-selective channels. However, most of them require maximum likelihood (ML) or near-ML detection at the receiver, which is of high complexity. On the other hand, empirical results have shown that linear detectors have low complexity but offer inferior performance. In this paper, we analytically quantify the diversity orders of linear equalizers for linear precoded OFDM systems, and prove that they are unable to collect full diversity. To improve the performance of linear equalizers, we further propose to use a lattice reduction (LR) technique to help collect diversity. The LR-aided linear equalizers are shown to achieve maximum diversity order (i.e., the one collected by the ML detector), but with low complexity that is comparable to that of conventional linear equalizers. The theoretical findings are corroborated by simulation results. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Decision-aided compensation of severe phase-impairment-induced inter-carrier interference in frequency-selective OFDM

    Page(s): 1614 - 1619
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2075 KB) |  | HTML iconHTML  

    A new, reduced complexity algorithm is proposed for compensating the Inter-Carrier Interference (ICI) caused by severe PHase Noise (PHN) and Residual Frequency Offset (RFO) in OFDM systems. The algorithm estimates and compensates the most significant terms of the frequency domain ICI process, which are optimally selected via a Minimum Mean Squared Error (MMSE) criterion. The algorithm requires minimal knowledge of the phase process statistics, the estimation of which is also considered. The scheme outperforms previously proposed compensation methods of similar complexity, when severe phase impairments are present. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • On capacity of cognitive radio networks with average interference power constraints

    Page(s): 1620 - 1625
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (394 KB) |  | HTML iconHTML  

    Cognitive radio (CR) has been considered as a promising technology to improve the spectrum utilization. In this paper we analyze the capacity of a CR network with average received interference power constraints. Under the assumptions of uniform node placements and a simple power control scheme, the maximum transmit power of a target CR transmitter is characterized by its cumulative distribution function (CDF). We study two CR scenarios for future applications. The first scenario is called the CR based central access network, which aims at providing broadband access to CR devices. In the second scenario, the so-called CR assisted virtual multiple-input multiple-output (MIMO) network, CR is used to improve the access capability of a cellular system. The uplink ergodic channel capacities of both scenarios are derived and analyzed with an emphasis on understanding the impact of numbers of primary users and CR users on the capacity. Numerical and simulation results suggest that the CR based central access network is more suitable for less-populated rural areas where a relatively low density of primary receivers is expected; while the CR assisted virtual MIMO network performs better in urban environments with a dense population of mobile CR users. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • On the capacity of Rayleigh fading cooperative systems under adaptive transmission

    Page(s): 1626 - 1631
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (274 KB) |  | HTML iconHTML  

    In this letter, the use of adaptive source transmission with amplify-and-forward relaying is proposed. Three different adaptive techniques are considered: (i) optimal simultaneous power and rate adaptation; (ii) constant power with optimal rate adaptation; (iii) channel inversion with fixed rate. The capacity upper bounds of these adaptive protocols are derived for the amplify-and-forward cooperative system over both independent and identically distributed (i.i.d.) Rayleigh fading and non-i.i.d. Rayleigh fading environments. The capacity analysis is based on an upper bound on the effective received signal-to-noise ratio (SNR). The tightness of the upper bound is validated by the use of a lower bound and by Monte Carlo simulation. It is shown that at high SNR the optimal simultaneous power and rate adaptation and the optimal rate adaptation with constant power provide roughly the same capacity. Channel inversion is shown to suffer from a deterioration in capacity relative to the other adaptive techniques. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Combined QRD-M and DFE detection technique for simple and efficient signal detection in MIMO-OFDM systems

    Page(s): 1632 - 1638
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (380 KB) |  | HTML iconHTML  

    An efficient MIMO signal detection technique with low complexity is presented for MIMO-OFDM systems. The proposed technique has a feature of combined QRD-M and DFE detection. In our detection technique with M transmit antennas, after QRD-M detection is executed for first T detection steps, DFE detection is executed for last M - T detection steps. This approach is simple and has low complexity, because the computations for QRD-M is limited by the newly adopted parameter T. From simulation results, the complexity of the proposed technique with 4 times 4 and T = 2 is reduced by 61% compared with that of the conventional QRD-M at the expense of about 0.7dB degradation of BER performance at BER=10-4. The simulations are executed in Ricean and Rayleigh channel models. And the simulation of proposed technique is executed by using estimated channel. Through the simulations, it is ascertained that the proposed detection can be used for Ricean and Rayleigh channel models as well as estimated channel. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • High altitude platform networks: A feedback suppression algorithm for reliable multicast/broadcast services

    Page(s): 1639 - 1643
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (196 KB) |  | HTML iconHTML  

    High Altitude Platforms (HAP) are currently considered as an alternative solution for providing reliable multicast and broadcast services. The major problem limiting the scalability of such systems is Feedback Implosion, a problem arising whenever a large number of users transmit their feedback messages. In the present Letter, a novel scheme is proposed which takes into account rain attenuation being the dominant factor impairing link performance. The proposed scheme is based on the selection of an Area Representative (AR) which is responsible for providing quick feedback messages to the HAP, thus suppressing feedback messages sent by other users. The proposed scheme is assessed both through analytical modeling and simulation with very satisfactory results. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Semianalytic BER for PSK

    Page(s): 1644 - 1648
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2267 KB) |  | HTML iconHTML  

    Semianalytic bit error rate (BER) estimation is a well-known method for evaluating the BER of a digital communication system. The main utility of the method is the significant time savings in computation relative to Monte Carlo simulation. Despite this advantage, no known reference defines the procedure for computing exact BER for M-ary phase shift keying (PSK) with ISI and AWGN using the semianalytic method. This letter defines an efficient procedure for computing exact semianalytic BER for modulation formats with circular constellations when the noise component of the decision variable has a circularly symmetric Gaussian distribution. The technique is demonstrated for 8PSK over the Digital Video Broadcasting-Satellite-Second Generation (DVB-S2) channel. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Generalized co-phasing for multiple transmit and receive antennas

    Page(s): 1649 - 1654
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (250 KB) |  | HTML iconHTML  

    We propose and study a class of transmit beamforming techniques for systems with multiple transmit and multiple receive antennas with a per-antenna transmit power constraint. The per-antenna transmit power constraint is more realistic than the widely used total (across all transmit antennas) power constraint, since in practice each transmit antenna is driven by a separate power amplifier with a maximum power rating. Under the per-antenna power constraint, from an implementation perspective, it becomes desirable to vary only the phases (as opposed to both power and phase variation) of the signals departing from the transmit antennas. We name this class of techniques generalized co-phasing and formulate an optimization problem to calculate the transmit antenna phases. Furthermore, we propose five heuristic algorithms to solve the optimization problem. All the proposed algorithms except one are optimal for the case of two transmit antennas and an arbitrary number of receive antennas. For an arbitrary number of transmit and receive antennas, simulations indicate that the proposed algorithms perform very close to the optimal solution calculated through an exhaustive search of all possible transmit phases. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • On game-theoretic power control under successive interference cancellation

    Page(s): 1655 - 1657
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (198 KB) |  | HTML iconHTML  

    Game-theoretic analytical techniques have been applied, of late, to uplink power control in DS-CDMA networks. We extend our previous analysis [1] of game-theoretic power control under successive interference cancellation performed under a dynamic cancellation ordering. Both continuous and discrete power control are investigated. Under continuous power control, we prove the nonexistence of a symmetric power control equilibrium, illustrating that no easily applicable equilibrium existence result applies to this power control problem. Under discrete power control, we demonstrate empirically a high probability of equilibrium if the action set is not too precise, an encouraging result in the absence of a pure-strategy equilibrium guarantee. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Comments on "Power controlled channel allocation for multiuser multiband UWB systems

    Page(s): 1658 - 1659
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (118 KB)  

    In this note, two typos in above-mentioned paper are pointed out and a sufficient condition to ensure the PER requirement in the optimization problem is provided. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Transmit antenna selection based strategies in MISO communication systems with low-rate channel state feedback

    Page(s): 1660 - 1666
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (245 KB) |  | HTML iconHTML  

    The performance of multiple-antenna communication systems is known to critically depend on the amount of channel state information (CSI) available at the transmitter. In the low-rate CSI feedback case, an important problem is what kind of information should be submitted to the transmitter in each feedback cycle and what is the optimal transmission strategy in this case. In this paper, we address this problem in the multiple-input single-output (MISO) case by analytically comparing the bit error rate (BER) performance of different low-rate feedback based transmitter strategies involving various combinations of transmit antenna selection, Alamouti's spacetime coding, and adaptive power allocation. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Switching rates of two-branch selection diversity in κ-μ and α-μ distributed fadings

    Page(s): 1667 - 1671
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (229 KB) |  | HTML iconHTML  

    An analytical expression for the switching rate of a dual branch selection diversity combiner in kappa-mu and alpha-mu distributed fadings is derived. Independent and identically distributed (i.i.d.) kappa-mu as well as alpha-mu fading channels are considered. The switching rates for dual i.i.d. Rayleigh, Rician and Nakagami-m fading channels are special cases of the switching rate for dual i.i.d. kappa-mu fading channels. Similarly, the general switching rates for dual alpha-mu fading channels also include special cases such as Rayleigh, Nakagami-m, and Weibull fading channels. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A probabilistic call admission control algorithm for WLAN in heterogeneous wireless environment

    Page(s): 1672 - 1676
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (384 KB) |  | HTML iconHTML  

    In an integrated WLAN and cellular network, if all mobile users whose connections originate in the cellular network migrate to the WLAN whenever they enter the double coverage area, the WLAN will be severely congested and its users will suffer from performance degradation. Therefore, we propose a Call Admission Control (CAC) algorithm that allows the WLAN to limit downward Vertical Handovers (VHOs) from the cellular network to reduce unnecessary VHO processing. Numerical and simulation results demonstrate that our CAC scheme reduces the unnecessary VHO processing while keeping the DVHO blocking rate within acceptable limits and maintaining reasonable throughput in the WLAN. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Cross-layer based transmit antenna selection for decision-feedback detection in correlated Ricean MIMO channels

    Page(s): 1677 - 1682
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (248 KB) |  | HTML iconHTML  

    In this paper, we investigate a cross-layer transmit antenna selection (AS) approach for the decision-feedback detector (DFD) over spatially correlated flat Rician fading multiple-input multiple-output (MIMO) channels. Closed-form expressions for the system throughput with both perfect and imperfect channel estimation are derived. Considering a training-based channel estimation technique, we show that the capacity-based AS is more robust to imperfect channel estimation. However, in all cases, the cross-layer AS delivers higher throughput gains than the capacity-based AS. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Nonparametric mobile speed estimation in fading channels: Performance analysis and experimental results

    Page(s): 1683 - 1692
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (364 KB) |  | HTML iconHTML  

    In this paper we propose a new speed estimation technique, applicable to both mobile and base stations, based on the characteristics in the power spectrum of mobile fading channels. Our analytic performance analysis, verified by Monte Carlo simulations, shows that our low-complexity estimator is not only robust to both Gaussian and non-Gaussian noises, but also insensitive to nonisotropic scattering observed at the mobile. The estimator performs very well in both two- and three-dimensional propagation environments. The robustness against both nonisotropic scattering and line of sight can be further increased, by taking advantage of resolvable paths in wideband fading channels, due to the differences among the Doppler spectra observed at different paths. We also extend this technique to base stations with antenna arrays. By exploiting the spatial information, the proposed space-time estimator exhibits excellent performance over a wide range of noise power, nonisotropic scattering, and line-of-sight component, verified by simulation. The utility of the new method is further demonstrated by applying it to the measured data. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Server allocation with delayed state observation: Sufficient conditions for the optimality of an index policy

    Page(s): 1693 - 1705
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (376 KB) |  | HTML iconHTML  

    In this paper we study an optimal server allocation problem, where a single server is shared among multiple queues based on the queue backlog information. Due to the physical nature of the system this information is delayed, in that when the allocation decision is made, the server only has the backlog information from an earlier time. Queues have different arrival processes as well as different buffering/holding costs. The objective is to minimize the expected total discounted holding cost over a finite or infinite horizon. We introduce an index policy where the index of a queue is a function of the state of the queue. Our primary interest is to characterize conditions under which this index policy is optimal. We present a fairly general method bounding the reward of serving one queue instead of another. Using this result, sufficient conditions on the optimality of the index policy can be derived for a variety of arrival processes and packet holding costs. These conditions are in general in the form of sufficient separation among indices, and they characterize the part of the state space where the index policy is optimal. We provide examples and derive the indices and illustrate the region where the index policy is optimal. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • J-CAR: An efficient joint channel assignment and routing protocol for IEEE 802.11-based multi-channel multi-interface mobile Ad Hoc networks

    Page(s): 1706 - 1715
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (481 KB) |  | HTML iconHTML  

    The capacity of an IEEE 802.11-based multi-hop wireless network is limited. By effectively utilizing multiple non-overlapping channels and multiple interfaces, collision and co-channel interference can be reduced. This allows more concurrent transmissions and thus enhances the network capacity. In this paper, we introduce an efficient distributed joint channel assignment and routing protocol, called J-CAR. Unlike existing schemes, J-CAR allows a data interface to dynamically change its routing protocol working mode between send and receive on a call-by-call basis, which distributed joint channel assignment enhances the utilization of both interface and channel. In J-CAR, channels are negotiated and assigned to active links in conjunction with the on-demand routing process. At each hop, J-CAR conducts a local optimization by selecting the least interfered channel according to the channel interference index. The channel interference index is designed by taking both the protocol and physical interference models into consideration. To find the least interfered path for network load balancing on a global scale, J-CAR employs a length-constrained widest-path routing. The ldquowidthrdquo of a path is determined by the interference level of its bottleneck link. With an adjustable threshold on the path length (with respect to the shortest-path), the excessively long path can also be avoided. We show that with a comparable complexity as the existing schemes, J-CAR provides much higher system good puts and shorter end-to-end packet delays. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Cooperative transmission based on decode-and-forward relaying with partial repetition coding

    Page(s): 1716 - 1725
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (365 KB) |  | HTML iconHTML  

    We propose a novel half-duplex decode-and-forward relaying scheme based on partial repetition coding at the relay. In the proposed scheme, if the relay decodes the received message successfully, it re-encodes the message using the same channel code as the one used at the source, but retransmits only a fraction of the codeword. We analyze the proposed scheme and optimize the cooperation level (i.e., the fraction of the message that the relay should transmit). We compare our scheme with conventional repetition in which the relay retransmits the entire decoded message, with parallel coding, and additionally with dynamic decode-and-forward (DDF). We provide a finite-SNR analysis for all the collaborative schemes. The analysis reveals that the proposed partial repetition method can provide a gain of several dB over conventional repetition. It also shows that in general, power allocation is less important provided that one optimally allocates bandwidth. Surprisingly, the proposed scheme is able to achieve the same performance as that of parallel coding for some relay network configurations, but at a much lower complexity. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Data dissemination in wireless broadcast channels: Network coding versus cooperation

    Page(s): 1726 - 1732
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (270 KB) |  | HTML iconHTML  

    Network coding and cooperative diversity have each extensively been explored in the literature as a means to substantially improve the performance of wireless networks. Yet, little work has been conducted to compare their performance under a common framework. Our goal in this paper is to fill in this gap. Specifically, we consider a single-hop wireless network consisting of a base station and N receivers. We perform an asymptotic analysis, as N rarr infin, of the expected delay associated with the broadcasting of a file consisting of K packets. We show that if K is fixed, cooperation outperforms network coding, in the sense that the expected delay is proportional to K (and thus within a constant factor of the optimal delay) in the former case while it grows logarithmically with N in the latter case. On the other hand, if K grows with N at a rate at least as fast as (logN)r, for r Gt 1, then we show that the average delay of network coding is also proportional to K and lower than the average delay of cooperation if the packet error probability is smaller than 0.36. Our analytical findings are validated through extensive numerical simulations. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Space-time duality in multiple antenna channels

    Page(s): 1733 - 1743
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (355 KB) |  | HTML iconHTML  

    The concept of information transmission in a multiple antenna channel with scattering objects is studied from first physical principles. The amount of information that can be transported by electromagnetic radiation is related to the space-wavenumber and the time-frequency spectra of the system composed by the transmitting antennas and the scattering objects, and to the spatial extension of the receiving domain. The spatial information content of the field is related to the number of relevant communication modes of the channel. It is shown that for narrow-band frequency transmission space and time can be decoupled, leading to a space-time information duality principle in the computation of the capacity of the radiating system. In contrast, in the case of wide-band frequency transmission, it is shown that time and space cannot be decoupled and they jointly characterize the wave's information content. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.

Aims & Scope

The IEEE Transactions on Wireless Communications publishes high-quality manuscripts on advances in the state-of-the-art of wireless communications.

Full Aims & Scope

Meet Our Editors

Editor-in-Chief
Jeff Andrews
Cullen Trust for Higher Education Endowed Professor of Engineering