Overcoming Interference in Spatial Multiplexing MIMO Cellular Networks
Accepted to IEEE Wireless Communications Magazine.
Multi-antenna transmission and reception (known as MIMO) is widely touted as the key technology for enabling wireless broadband services, whose widespread success will require ten times higher spectral efficiency than current cellular systems, at ten times lower cost per bit. Spectrally efficient, inexpensive cellular systems are by definition densely populated and interference-limited. But spatial multiplexing MIMO systems Ð whose principal merit is a supposed dramatic increase in spectral efficiency Ð lose much of their effectiveness in high levels of interference. This paper overviews several approaches for handling interference in multicell MIMO systems. The discussion is applicable to any multi-antenna cellular network including 802.16e/WiMAX, 3GPP (HSDPA and 3GPP LTE) and 3GPP2 (1xEVDO). We argue that many of the traditional interference management techniques have limited usefulness (or are even counterproductive) when viewed in concert with MIMO. The problem of interference in MIMO systems is too large in scope to be handled with a single technique: in practice a combination of complementary countermeasures will be needed. We overview emerging system-level interference- reducing strategies based on cooperation, which will be important for overcoming interference in future spatial multiplexing cellular systems.
This paper is available IEEE Xplore.