Approximative matrix inverse computations for very-large MIMO and applications to linear pre-coding systems

Prabhu H, Rodrigues J, Edfors O, Rusek F (2013)


Publication Type: Conference contribution

Publication year: 2013

Pages Range: 2710-2715

Conference Proceedings Title: IEEE Wireless Communications and Networking Conference, WCNC

Event location: CHN

ISBN: 9781467359399

DOI: 10.1109/WCNC.2013.6554990

Abstract

In very-large multiple-input multiple-output (MIMO) systems, the base station (BS) is equipped with very large number of antennas as compared to previously considered systems. There are various advantages of increasing the number of antennas, and some schemes require handling large matrices for joint processing (pre-coding) at the BS. The dirty paper coding (DPC) is an optimal pre-coding scheme and has a very high complexity. However, with increasing number of BS antennas, linear pre-coding performance tends to that of the optimal DPC. Although linear pre-coding is less complex than DPC, there is a need to compute pseudo inverses of large matrices. In this paper we present a low complexity approximation of down-link Zero Forcing (ZF) linear pre-coding for very-large multi-user MIMO systems. Approximation using a Neumann series expansion is opted for inversion of matrices over traditional exact computations, by making use of special properties of the matrices, thereby reducing the cost of hardware. With this approximation of linear pre-coding, we can significantly reduce the computational complexity for large enough systems, i.e., where we have enough BS antenna elements. For the investigated case of 8 users, we obtain 90% of the full ZF sum rate, with lower computational complexity, when the number of BS antennas per user is about 20 or more. © 2013 IEEE.

Involved external institutions

How to cite

APA:

Prabhu, H., Rodrigues, J., Edfors, O., & Rusek, F. (2013). Approximative matrix inverse computations for very-large MIMO and applications to linear pre-coding systems. In IEEE Wireless Communications and Networking Conference, WCNC (pp. 2710-2715). CHN.

MLA:

Prabhu, Hemanth, et al. "Approximative matrix inverse computations for very-large MIMO and applications to linear pre-coding systems." Proceedings of the 2013 IEEE Wireless Communications and Networking Conference, WCNC 2013, CHN 2013. 2710-2715.

BibTeX: Download