Abstract
In this paper, we propose a non-iterative symbol-wise beamforming scheme for MIMO-OFDM systems, which can provide the performance approaching that of the iterative symbol-wise beamforming scheme and can reduce the computational complexity significantly for channels with a small number of strong channel taps. Simulation results show that our proposed scheme leads to a negligible performance loss compared with the iterative symbol-wise beamforming scheme regardless of spatial correlation or presence of co-channel interference. For realistic situations, we also consider the system designs to manage imperfect channel knowledge at the transmitter or receiver. First, we propose a limited feedback technique and a codebook design algorithm for symbol-wise beamforming in a spatially correlated frequency selective channel. Simulation results show that the proposed limited feedback technique can provide insignificant outage capacity loss compared with the symbol-wise beamforming scheme with perfect channel knowledge when the proposed codebook is adopted with a moderate number of feedback bits. Second, we propose a robust transceiver optimization for symbol-wise beamforming under channel uncertainty. From simulation results, we confirm that our proposed robust transceiver optimization can incur less degradation than the iterative and proposed symbol-wise beamforming schemes under the assumption of a bounded channel uncertainty model.
Original language | English |
---|---|
Article number | 6287529 |
Pages (from-to) | 3788-3798 |
Number of pages | 11 |
Journal | IEEE Transactions on Wireless Communications |
Volume | 11 |
Issue number | 10 |
DOIs | |
Publication status | Published - 2012 |
Bibliographical note
Funding Information:Manuscript received March 20, 2012; revised July 19, 2012; accepted July 26, 2012. The associate editor coordinating the review of this paper and approving it for publication was S. Bhashyam. This research was supported by the KCC (Korea Communications Commission), Korea, under the R&D program supervised by the KCA (Korea Communications Agency) (KCA-2012-08-911-04-002). The material in this paper was presented in part at the IEEE Global Communications Conference (GLOBECOM), Houston, TX, USA, Dec. 2011. The authors are with the School of Electrical Engineering, Korea University, Seoul 136-713, Korea (e-mail: {hh2432, koyc}@korea.ac.kr). Digital Object Identifier 10.1109/TWC.2012.081612.120406
Keywords
- MIMO-OFDM
- imperfect channel knowledge
- limited feedback
- robust transceiver
- symbol-wise beamforming
ASJC Scopus subject areas
- Computer Science Applications
- Electrical and Electronic Engineering
- Applied Mathematics