Analysis of MIMO Systems in the Presence of Co-channel Interference and Spatial Correlation

Abstract

Wireless communication systems employing multiple antenna elements at the transmitter and the receiver have been attracting much interest in recent years due to the significant capacity gain promised by the multiple-input multiple-output (MIMO) systems [Teletar (1999)], [Foschini & Gans (1998)]. The MIMO systems have been analyzed deeply from two different perspectives [Teletar (1999)]-[Yue & Zhang (2010)]: one concerns the evaluation of the information-theoretic (Shannon) capacity, the other concerns performance evaluation in terms of outage probability or symbol error probability of practical systems. Both of the capacity analysis and performance analysis strongly rely on random matrix theory and matrix variate distributions. So far the capacity issues of MIMO systems have been extensively studied in the literature, yet with main focus on the scenario without interference [Teletar (1999)]-[Kiessling (2005)]. In cellular systems, however, multiple users share the same radio spectrum, which typically causes co-channel interference. It is well known that co-channel interference ultimately limits the quality of service offered to the users. There have been initial investigations for the MIMO capacity with co-channel interference in fading environments [Catreux et al. (2000)]-[Kang & Alouini (2003a)]. In particular, Song and Blostein [Song& Blostein (2002)] studied the behavior of MIMO capacity with varying number of interferers through simulations. In [Kang et al. (2007)] and [Kang & Alouini (2003a)], Kang et al. obtained exact closed-form expressions for the moment generating function, mean, variance of MIMO capacity. Specifically, the paper [Kang et al. (2007)] considered MIMO Rayleigh fading channels in the presence of additive noise and interferers with arbitrary average powers, but requiring that there is no spatial correlation both among transmit antenna elements and among receive antenna elements for the desired user, and there is no correlation among receive antenna elements for any interferer. Reference [Kang & Alouini (2003a)] considered MIMO Rician channels in the presence of Rayleigh co-channel interference, but requiring that there is an identical correlation structure among receive antenna elements for both the desired user and interferers, and there is no correlation among their transmit antenna elements. In many practical situations, however, signal correlation among the antenna elements exists in realistic environments due to poor scattering conditions. A typical example of this is an uplink transmission from a mobile station (MS) to a base station (BS) , where around the 7