Abstract This paper presents analytical results on the capacity of multiple‐input‐multiple‐output (MIMO) fading channels in the presence of co‐channel interference (CCI). We consider the scenario in which the desired and CCI users are all subject to Rayleigh fading. We assume that channel realizations of both the desired and CCI users are known at the receiver. Moreover, we consider the case where the transmitter does not have any CSI and as such equal‐power allocation among transmit antennas is used. Given this setup, we derive the moment generating function (MGF) and the mean of the mutual information (MI). We then study the complementary cumulative distribution function of the MI using a Gaussian approximation. Finally, we present and discuss numerical examples to illustrate the mathematical formalism and to show the effect of various parameters on the capacity of MIMO channels in the presence of CCI. Copyright © 2006 John Wiley & Sons, Ltd.

This paper presents exact results on the capacity of multiple-input-multiple-output (MIMO) Rician channels when perfect channel state information (CSI) is assumed at the receiver but the transmitter has neither instantaneous nor statistical CSI. It first derives the exact expression for the average mutual information (MI) rate of MIMO Rician fading channels when the fading coefficients are independent but not necessarily identically distributed. The results for the independent and identically distributed (i.i.d.) MIMO Rician and Rayleigh fading channels are also obtained as special cases. These results are derived using a different approach than the one used by Telatar for the i.i.d. Rayleigh case. The complementary cumulative distribution function (CCDF) of the MI is also obtained using a Gaussian approximation. The CDF of MI can serve as an upper bound to the outage probability of nonergodic MIMO Rician channels. Numerical results confirm that for a fixed channel gain, a strong tine-of-sight component decreases the channel capacity due to the lack of scattering.

Abstract-This paper presents some exact results on the capacity of multiple-input-multiple-output (MIMO) channels subject to correlated Rayleigh fading when perfect channel state information (CSI) is known at the receiver. The authors focus on the semicorrelated scenario in which correlation exists either at the transmitter or at the receiver., They consider two cases: 1) the transmitter does not have any CSI and as such allocates power equally among transmitter antennas and 2) the transmitter only knows the statistical distribution of the channel. The first case derives the moment generating function (MGF) of the mutual information (MI) and then deduces from this MGF the mean MI. The authors also study the cumulative distribution function (CDF) of the MI, which can serve as an upper bound to the outage probability under the capacity versus outage formulation when the channel is nonergodic. The second case studies the capacity achieved by optimum power-loading and beamforming schemes based on covariance feedback. Numerical results illustrate that the full capacity of MIMO systems can be preserved even for relatively high values of correlation coefficients.

This paper studies the performance of multiple-input-multiple-output (MIMO) systems with optimum combining in the presence of both co-channel interference (CCI) and noise. We assume that both desired and CCI users are subject to Rayleigh fading and allow the number of CCI users to be arbitrary and their short-term average powers to be non-identical. Given these assumptions, we derive exact results on the cumulative distribution function (CDF) of the output signal-to-interference-plus-noise ratio (SINR), or equivalently, the outage probability of this MIMO optimum combining scheme. Finally, we present and discuss some numerical examples to validate our analytical expressions and to show the effect of CCI on the performance of MIMO optimum combining systems

Multiple description coding (MDC) is an error-resilient scheme for transmission over packet erasure channels. In this paper, we propose a channel-balancing scheme for the transmission of an MDC source over time-varying channels, such as wireless links. We consider a system in which there are more subchannels than the number of descriptions and the transmission rate is adapted to the channel variation. The proposed balancing scheme is based on the polynomial-time set-partitioning algorithm using the differencing method. It is shown that the proposed scheme results in a low-delay and high-throughput transmission, which is desirable for real-time multimedia content delivery over wireless channels.

This paper presents exact closed-form expressions for the performance of multiple-input/multiple-output systems employing maximal ratio combining in the absence and presence of cochannel interference. The results are applicable to systems operating over Rayleigh fading channels, and in which the minimum number of antenna elements at the transmitter and receiver is two. The mathematical formalism is illustrated by some numerical examples which study the effects of various parameters on the system performance.

This paper establishes an analytical framework for the performance analysis of multiple-input/multiple output (MIMO) systems subject to cochannel interference and operating over fading channels. First, we present some new statistical results dealing with the distribution of the largest eigenvalue of certain quadratic forms in complex Gaussian matrices and establish the connection between these results and the performance analysis of MIMO systems subject to cochannel interference. We consider interference limited systems in which the number of cochannel interferers exceeds or is equal to the number of receiving antenna elements. We then derive new "closed-form" expressions of the probability density function of the outage signal-to-interference ratio and the system outage probability for MIMO systems in Rician-Rayleigh (i.e., the desired user is subject to Rician fading while cochannel interferers are subject to Rayleigh fading) and Rayleigh-Rayleigh fading environments. When applicable, these expressions are compared to special cases previously reported in the literature dealing with the performance of single-input/multiple-output (SIMO) systems. As a double check, these analytical results and assumptions are validated by Monte Carlo simulations and as an illustration of the mathematical formalism some numerical examples for particular cases of interests are plotted and discussed. These results show that under the same the scattering and interfering conditions and given a fixed number of total antenna elements and cochannel interferers: 1) SIMO systems will always outperform multiple-input/single-output systems and 2) it is preferable to distribute the number of antenna elements evenly between the transmitter and the receiver for an optimum performance.

This paper presents some analytical results on the capacity of multiple-input-multiple-output Rician channels in the presence of Rayleigh co-channel interference. We consider interference-limited systems and derive the exact moment generating function, mean, and variance of the isolated link capacity when the transmitter has no channel state information. We then capitalize on these results to obtain Gaussian and Chi-Square approximations for the capacity complimentary cumulative distribution function (CCDF). Numerical results, comparing these two approximations to exact results obtained by Monte-Carlo simulations, show that both approximations yield very good prediction of the capacity CCDF for a wide range of transmitting power and number of antennas.

This paper presents exact closed-form expressions for the performance of multiple-input multiple output (MIMO) systems employing maximal ratio combining (MRC) in absence and presence of co-channel interference (CCI). The results are applicable to systems operating over Rayleigh fading channels and in which the minimum number of antenna elements at the transmitter and receiver is two. The mathematical formalism is illustrated by some numerical examples showing the effects of various parameters ob the system performance.

This paper presents exact results on (i) the moment generating function (MGF) of the multiple-input-multiple-output (MIMO) channel capacity and (ii) the outage probability and the capacity complementary distribution function (CCDF) of MIMO maximal ratio combining (MRC) systems both in correlated Rayleigh fading environment. We then deduce from the first result both the mean and the variance of this capacity as well as the Gaussian-approximated capacity CCDF. The mathematical formalism is illustrated by some numerical examples that show the impact of various parameters on the capacity of correlated MIMO channels.

This paper extends Khatri (1964, 1969) distribution of the largest eigenvalue of central complex Wishart matrices to the noncentral case. It then applies the resulting new statistical results to obtain closed-form expressions for the outage probability of multiple-input-multiple-output (MIMO) systems employing maximal ratio combining (known also as "beamforming" systems) and operating over Rician-fading channels. When applicable these expressions are compared with special cases previously reported in the literature dealing with the performance of (1) MIMO systems over Rayleigh-fading channels and (2) single-input-multiple-output (SIMO) systems over Rician-fading channels. As a double check these analytical results are validated by Monte Carlo simulations and as an illustration of the mathematical formalism some numerical examples for particular cases of interest are plotted and discussed. These results show that, given a fixed number of total antenna elements and under the same scattering condition (1) SIMO systems are equivalent to multiple-input-single-output systems and (2) it is preferable to distribute the number of antenna elements evenly between the transmitter and the receiver for a minimum outage probability performance.

Two-dimensional (2D) RAKE (2D-RAKE) receivers process signals in both time and space to improve the performance of code-division multiple-access (CDMA) systems. We establish the connection between the 2D-RAKE signal-to-interference-ratio (SIR) output statistics and the generalized Hotelling's (1947, 1951, 1931) T/sup 2//sub 0/ (in the complex case) distribution. We study this distribution and offer new simple explicit closed-form expressions (in terms of hypergeometric functions) for its probability density function (PDF) and cumulative distribution function (CDF). Based on that, we derive the outage probability of dual-branch 2D-RAKE receivers over Rayleigh-fading channels. Some numerical examples for particular cases of interests are plotted and discussed.

Relying on the Khatri distribution of the largest eigenvalue of certain quadratic forms in complex Gaussian vectors, we develop an analytical framework for the performance analysis of multiple-input-multiple output (MIMO) systems subject to cochannel interference and operating over Rayleigh fading channels. We consider interference limited systems in which the number of interferers exceeds or is equal to the number of receiving antenna elements and we present new closed-form expressions for the probability density function of the output signal-to-interference ratio and for the MIMO system outage probability. When applicable, these expressions are compared to the special case which dealt with the performance of single-input-multiple-output (SIMO) systems (see Shah, A. and Haimovich, A.M., IEEE Trans. Commun., vol.46, p.473-9, 1998). These analytical results are validated by Monte-Carlo simulations and as an illustration of the mathematical formalism some numerical examples for particular cases of interest are plotted and discussed. The results show that, given a fixed number of total antenna elements and cochannel interferers, (i) SIMO systems always outperform multiple-input-single-output systems and (ii) it is preferable to distribute the number of antenna elements evenly between the transmitter and the receiver for optimum performance.

Relying on the distribution of noncentral multivariate F variates, we investigate the outage probability and spectrum efficiency performance of cellular systems with smart antennas. We consider interference-limited systems in which the number of interferers exceeds or is equal to the number of antenna elements, and we present closed-form expressions when the desired signal is subject to Rician-type fading and interfering signals exhibit Rayleigh-, or, more general Nakagami-type fading. When applicable, these new expressions are compared to those previously reported in the literature dealing with the performance of cellular systems without smart antenna capabilities and the performance of cellular systems with optimum combining when both the desired and interfering signals are subject to Rayleigh-type fading. Corresponding numerical results and plots are also provided and discussed.

Two-dimensional (2D)-RAKE receivers process signals in both time and space to improve the performance of code division multiple access (CDMA) systems. We establish the connection between the 2D-RAKE signal-to-interference-ratio (SIR) output statistics and the generalized Hotelling's T/sub 0//sup 2/ (in the complex case) distribution. We study this distribution and offer new simple explicit closed-form expressions (in terms of hypergeometric functions) for its probability density function (PDF) and cumulative distribution function (CDF). Based on that, we derive the outage probability of dual-branch 2D-RAKE receivers over Rayleigh fading channels. As a double check these analytical results are validated by Monte-Carlo simulations and some numerical examples, for particular cases of interest, are plotted and discussed.

Relying on the distribution of noncentral multivariate F variates, we investigate the outage probability and spectrum efficiency performance of microcellular and picocellular (indoor) systems with smart antennas. We consider interference limited systems in which the number of interferers exceed or is equal to the number of antenna elements and we present closed-form expressions when the desired signal is subject to Rician type of fading and the interfering signals exhibit Rayleigh type of fading. When applicable these new expressions are compared to those previously reported in the literature dealing with the performance of cellular systems without smart antenna capabilities and the performance of cellular systems with optimum combining when both the desired and interfering signals are subject to Rayleigh type of fading. Corresponding numerical results and plots are also provided and discussed.