A new approach to beamformer design for massive MIMO systems based on k-Regularity

• Main Authors: Gilwon Lee, Juho Park, Youngchul Sung, Junyeong Seo
• Format: Conference Proceeding
• Language: English
• Subjects: Algorithm design and analysis; Array signal processing; Complexity theory; MIMO; Transmitting antennas; Vectors
• ISSN: 2166-0077; 2166-0077
• DOI: 10.1109/GLOCOMW.2012.6477657

In this paper, a new beamformer design paradigm, named k-regular beamformer, is proposed for massive multiple-input multiple-output (MIMO) transmission systems to achieve most of the gain inherent to a large antenna array without too much complexity. In the proposed k-regular beamforming scheme, each of multiple data streams for MIMO transmission is multiplied by k complex gains and assigned to k out of available N T transmit antennas, and signals assigned to the same transmit antenna are added and transmitted through the assigned antenna. The proposed k-regular beamformer can implement antenna selection (corresponding to k=1) to optimal eigen-beamforming (corresponding to k=N T ) by controlling the parameter k, and thus enables arbitrary trade-off between complexity and performance. Two beamformer design algorithms, the maximum correlation method (MCM) and the projected iterative shrinkage-thresholding algorithm (PISTA), are proposed to design k-regular beamforming matrices. Numerical results show that the proposed k-regular beamformer even with small k significantly improves the rate gain over simple antenna selection and achieves most of the optimal eigen-beamforming performance with far less complexity than that required for optimal eigen-beamforming for massive MIMO transmission.