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Spacetime codes for high data rate wireless communication: Performance criterion and code construction
 IEEE TRANS. INFORM. THEORY
, 1998
"... We consider the design of channel codes for improving the data rate and/or the reliability of communications over fading channels using multiple transmit antennas. Data is encoded by a channel code and the encoded data is split into n streams that are simultaneously transmitted using n transmit ant ..."
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Cited by 1368 (26 self)
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We consider the design of channel codes for improving the data rate and/or the reliability of communications over fading channels using multiple transmit antennas. Data is encoded by a channel code and the encoded data is split into n streams that are simultaneously transmitted using n transmit antennas. The received signal at each receive antenna is a linear superposition of the n transmitted signals perturbed by noise. We derive performance criteria for designing such codes under the assumption that the fading is slow and frequency nonselective. Performance is shown to be determined by matrices constructed from pairs of distinct code sequences. The minimum rank among these matrices quantifies the diversity gain, while the minimum determinant of these matrices quantifies the coding gain. The results are then extended to fast fading channels. The design criteria are used to design trellis codes for high data rate wireless communication. The encoding/decoding complexity of these codes is comparable to trellis codes employed in practice over Gaussian channels. The codes constructed here provide the best tradeoff between data rate, diversity advantage, and trellis complexity. Simulation results are provided for 4 and 8 PSK signal sets with data rates of 2 and 3 bits/symbol, demonstrating excellent performance that is within 2–3 dB of the outage capacity for these channels using only 64 state encoders.
Performance Limits of Coded Diversity Methods for Transmitter Antenna Arrays
 IEEE Trans. Inform. Theory
, 1999
"... Several aspects of the design and optimization of coded multipleantenna transmission diversity methods for slowly timevarying channels are explored from an informationtheoretic perspective. Both optimized vectorcoded systems, which can achieve the maximum possible performance, and suboptimal sca ..."
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Cited by 71 (3 self)
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Several aspects of the design and optimization of coded multipleantenna transmission diversity methods for slowly timevarying channels are explored from an informationtheoretic perspective. Both optimized vectorcoded systems, which can achieve the maximum possible performance, and suboptimal scalarcoded systems, which reduce complexity by exploiting suitably designed linear precoding, are investigated. The achievable rates and associated outage characteristics of these spatial diversity schemes are evaluated and compared, both for the case when temporal diversity is being jointly exploited and for the case when it is not. Complexity and implementation issues more generally are also discussed.
MultiCell MIMO Cooperative Networks: A New Look at Interference
 J. Selec. Areas in Commun. (JSAC
, 2010
"... Abstract—This paper presents an overview of the theory and currently known techniques for multicell MIMO (multiple input multiple output) cooperation in wireless networks. In dense networks where interference emerges as the key capacitylimiting factor, multicell cooperation can dramatically improv ..."
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Cited by 49 (18 self)
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Abstract—This paper presents an overview of the theory and currently known techniques for multicell MIMO (multiple input multiple output) cooperation in wireless networks. In dense networks where interference emerges as the key capacitylimiting factor, multicell cooperation can dramatically improve the system performance. Remarkably, such techniques literally exploit intercell interference by allowing the user data to be jointly processed by several interfering base stations, thus mimicking the benefits of a large virtual MIMO array. Multicell MIMO cooperation concepts are examined from different perspectives, including an examination of the fundamental informationtheoretic limits, a review of the coding and signal processing algorithmic developments, and, going beyond that, consideration of very practical issues related to scalability and systemlevel integration. A few promising and quite fundamental research avenues are also suggested. Index Terms—Cooperation, MIMO, cellular networks, relays, interference, beamforming, coordination, multicell, distributed.
Sum Rate Characterization of Joint Multiple CellSite Processing
, 2005
"... The sumrate capacity of a cellular system model is analyzed, considering the uplink and downlink channels, while addressing both nonfading and flatfading channels. The focus is on a simple Wynerlike multicell model, where the system cells are arranged on a circle, assuming the cellsites are lo ..."
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Cited by 29 (10 self)
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The sumrate capacity of a cellular system model is analyzed, considering the uplink and downlink channels, while addressing both nonfading and flatfading channels. The focus is on a simple Wynerlike multicell model, where the system cells are arranged on a circle, assuming the cellsites are located at the boundaries of the cells. For the uplink channel, analytical expressions of the sumrate capacities are derived for intracell TDMA scheduling, and a “WideBand ” (WB) scheme (where all users are active simultaneously utilizing all bandwidth for coding). Assuming individual percell power constraints, and using the Lagrangian uplinkdownlink duality principle, an analytical expression for the sumrate capacity of the downlink channel is derived for nonfading channels, and shown to coincide with the corresponding uplink result. Introducing flatfading, lower and upper bounds on the average percell sumrate capacity are derived. The bounds exhibit an O(loge K) multiuser diversity factor for a number of users percell K ≫ 1, in addition to the array diversity gain. Joint multicell processing is shown to eliminate outofcell interference, which is traditionally considered to be a limiting factor in highrate reliable communications. This paper was presented in part at the 9
On Certain Large Random Hermitian Jacobi Matrices with Applications to Wireless Communications
, 2007
"... In this paper we study the spectrum of certain large random Hermitian Jacobi matrices. These matrices are known to describe certain communication setups. In particular we are interested in an uplink cellular channel which models mobile users experiencing a softhandoff situation under joint multicel ..."
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Cited by 3 (2 self)
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In this paper we study the spectrum of certain large random Hermitian Jacobi matrices. These matrices are known to describe certain communication setups. In particular we are interested in an uplink cellular channel which models mobile users experiencing a softhandoff situation under joint multicell decoding. Considering rather general fading statistics we provide a closed form expression for the percell sumrate of this channel in highSNR, when an intracell TDMA protocol is employed. Since the matrices of interest are tridiagonal, their eigenvectors can be considered as sequences with second order linear recurrence. Therefore, the problem is reduced to the study of the exponential growth of products of two by two matrices. For the case where K users are simultaneously active in each cell, we obtain a series of lower and upper bound on the highSNR power offset of the percell sumrate, which are considerably tighter than previously known bounds. I.
On the Spectrum of Large Random Hermitian FiniteBand Matrices
, 805
"... Abstract — The open problem of calculating the limiting spectrum (or its Shannon transform) of increasingly large random Hermitian finiteband matrices is described. In general, these matrices include a finite number of nonzero diagonals around their main diagonal regardless of their size. Two diff ..."
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Cited by 1 (1 self)
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Abstract — The open problem of calculating the limiting spectrum (or its Shannon transform) of increasingly large random Hermitian finiteband matrices is described. In general, these matrices include a finite number of nonzero diagonals around their main diagonal regardless of their size. Two different communication setups which may be modeled using such matrices are presented: a simple cellular uplink channel, and a time varying intersymbol interference channel. Selected recent informationtheoretic works dealing directly with such channels are reviewed. Finally, several characteristics of the still unknown limiting spectrum of such matrices are listed, and some reflections are touched upon. I. PROBLEM DESCRIPTION Consider a linear channel of the form y = HNx + z, (1) where x is the NK × 1 zeromean complex Gaussian input vector x ∼ CN(0, P K INK) 1, y is the N × 1 output vector, and z denotes the N ×1 zeromean complex Gaussian additive noise vector z ∼ CN(0, INK), which is independent of x and HN. Accordingly ρ = P K is the transmitted signaltonoise ratio (SNR). In addition, the N ×NK channels transfer matrix HN is defined by HN = 0
1 On Information Rates of the Fading Wyner Cellular Model via the Thouless Formula for the Strip
, 2008
"... We apply the theory of random Schrödinger operators to the analysis of multiusers communication channels similar to the Wyner model, that are characterized by shortrange intracell broadcasting. With H the channel transfer matrix, HH † is a narrowband matrix and in many aspects is similar to a ra ..."
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We apply the theory of random Schrödinger operators to the analysis of multiusers communication channels similar to the Wyner model, that are characterized by shortrange intracell broadcasting. With H the channel transfer matrix, HH † is a narrowband matrix and in many aspects is similar to a random Schrödinger operator. We relate the percell sumrate capacity of the channel to the integrated density of states of a random Schrödinger operator; the latter is related to the top Lyapunov exponent of a random sequence of matrices via a version of the Thouless formula. Unlike related results in classical random matrix theory, limiting results do depend on the underlying fading distributions. We also derive several bounds on the limiting percell sumrate capacity, some based on the theory of random Schrödinger operators, and some derived from information theoretical considerations. Finally, we get explicit results in the highSNR regime for some particular cases.
1 On Certain Large Random Hermitian Jacobi Matrices with Applications to Wireless Communications
, 2008
"... In this paper we study the spectrum of certain large random Hermitian Jacobi matrices. These matrices are known to describe certain communication setups. In particular we are interested in an uplink cellular channel which models mobile users experiencing a softhandoff situation under joint multicel ..."
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In this paper we study the spectrum of certain large random Hermitian Jacobi matrices. These matrices are known to describe certain communication setups. In particular we are interested in an uplink cellular channel which models mobile users experiencing a softhandoff situation under joint multicell decoding. Considering rather general fading statistics we provide a closed form expression for the percell sumrate of this channel in highSNR, when an intracell TDMA protocol is employed. Since the matrices of interest are tridiagonal, their eigenvectors can be considered as sequences with second order linear recurrence. Therefore, the problem is reduced to the study of the exponential growth of products of two by two matrices. For the case where K users are simultaneously active in each cell, we obtain a series of lower and upper bound on the highSNR power offset of the percell sumrate, which are considerably tighter than previously known bounds.
Symmetric Rate Capacity of Cellular Systems with Cooperative Base Stations
"... Abstract — Cooperation among base stations has demonstrated substantial capacity gain in cellular systems. The optimal transmission scheme under full base station cooperation requires all users to transmit simultaneously and a central joint receiver for multiuser detection. We consider some subopt ..."
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Abstract — Cooperation among base stations has demonstrated substantial capacity gain in cellular systems. The optimal transmission scheme under full base station cooperation requires all users to transmit simultaneously and a central joint receiver for multiuser detection. We consider some suboptimal but more practical schemes of orthogonal channel access either within a cell (intracell TDMA) or among cells (intercell time sharing), which correspond to a partitioning of overall channel resources. The effects of various schemes on the uplink capacity of a cellular system are then compared for a modified Wyner model [1]. I.
Distributed Antenna Processing in Cellular Systems
, 2007
"... This chapter presents a survey of information theoretic results available on DAS in cellular systems. The treatment focuses on the derivation of the sumrate of different intercell and intracell communications strategies for both uplink and downlink. A simple symmetric family of cellular models in ..."
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This chapter presents a survey of information theoretic results available on DAS in cellular systems. The treatment focuses on the derivation of the sumrate of different intercell and intracell communications strategies for both uplink and downlink. A simple symmetric family of cellular models in which the intercell interferences are emerging from a the adjacent cells only is considered. Although hardly realistic, this family of models accounts for essential parameters of cellular systems such as intercell interference and fading. Whenever computation of the sumrate is intractable or yields little insight into the problem, asymptotic performance criteria (e.g. extremeSNR parameters) are evaluated. Emphasis is placed on the assessment of benefits of cooperation among APs (i.e. joint detection/precoding). 1 2CHAPTER 1. AN INFORMATION THEORETIC VIEW OF DISTRIBUTED ANTENNA PROCESS Mathematical tools underlying the results are introduced briefly where necessary. Finally, some advanced topics, such as cooperation among terminals, are discussed as well. 1.1