We investigate nonlinear precoding techniques for a multiuser multiple-inputmultiple-output (MU-MIMO) downlink. When assuming full knowledge of the channel state information (CSI) at the transmitter, a vector perturbation (VP), based on sphere encoding, is a promising precoding scheme that approaches sum capacity while using a simple receiver. However, its encoding complexity can exponentially increase with the number of transmit antennas. This paper proposes a new VP scheme based on line encoding (LE), which provides very low complexity as well as competent throughput performance. For this purpose, the proposed LE scheme finds the smallest set of candidate vectors, including the optimal perturbation vector with high probability.
Bibliographical noteFunding Information:
Manuscript received March 28, 2010; revised July 29, 2010 and October 12, 2010; accepted October 19, 2010. Date of publication November 22, 2010; date of current version February 18, 2011. This work was supported in part by the Korea Science and Engineering Foundation through the NRL Program under Grant R0A-2007-000-20043-0 and in part by The Ministry of Knowledge Economy, Korea, under the Information Technology Research Center support program supervised by the National IT Industry Promotion Agency (NIPA) under Grant NIPA-2010–(C1090-1011-0005). The review of this paper was coordinated by Prof. W. A. Hamouda.
All Science Journal Classification (ASJC) codes
- Automotive Engineering
- Aerospace Engineering
- Electrical and Electronic Engineering
- Applied Mathematics