TY - GEN
T1 - Energy-efficient configuration of spatial and frequency resources in MIMO-OFDMA systems
AU - Xu, Zhikun
AU - Yang, Chenyang
AU - Li, Geoffrey Ye
AU - Zhang, Shunqing
AU - Chen, Yan
AU - Xu, Shugong
PY - 2012
Y1 - 2012
N2 - In this paper, we investigate adaptive configuration of spatial and frequency resources to maximize energy efficiency (EE) and reveal the relationship between the EE and the spectral efficiency (SE) in downlink multiple-input-multiple-output (MIMO) orthogonal frequency division multiple access (OFDMA) systems. We formulate the problem as minimizing the total power consumed at the base station under constraints on the average data rates from multiple users, the total number of subcarriers, and the number of radio frequency (RF) chains. We develop a two-step searching algorithm to solve this problem, which first finds the near-optimal numbers of subcarriers for multiple users based on Karush-Kuhn-Tucker (KKT) conditions and then optimize the number of active RF chains. Simulation results demonstrate that increasing frequency resource improves both the SE and the EE, and is more efficient than increasing spatial resource. Consequently, there exists tradeoff between the SE and the EE only when the frequency resource is limited. In general, the adaptive configuration of spatial and frequency resources outperforms the adaptive configuration of only spatial resource and that of only frequency resource.
AB - In this paper, we investigate adaptive configuration of spatial and frequency resources to maximize energy efficiency (EE) and reveal the relationship between the EE and the spectral efficiency (SE) in downlink multiple-input-multiple-output (MIMO) orthogonal frequency division multiple access (OFDMA) systems. We formulate the problem as minimizing the total power consumed at the base station under constraints on the average data rates from multiple users, the total number of subcarriers, and the number of radio frequency (RF) chains. We develop a two-step searching algorithm to solve this problem, which first finds the near-optimal numbers of subcarriers for multiple users based on Karush-Kuhn-Tucker (KKT) conditions and then optimize the number of active RF chains. Simulation results demonstrate that increasing frequency resource improves both the SE and the EE, and is more efficient than increasing spatial resource. Consequently, there exists tradeoff between the SE and the EE only when the frequency resource is limited. In general, the adaptive configuration of spatial and frequency resources outperforms the adaptive configuration of only spatial resource and that of only frequency resource.
UR - http://www.scopus.com/inward/record.url?scp=84871967332&partnerID=8YFLogxK
U2 - 10.1109/ICC.2012.6364314
DO - 10.1109/ICC.2012.6364314
M3 - Conference Proceeding
AN - SCOPUS:84871967332
SN - 9781457720529
T3 - IEEE International Conference on Communications
SP - 4384
EP - 4389
BT - 2012 IEEE International Conference on Communications, ICC 2012
T2 - 2012 IEEE International Conference on Communications, ICC 2012
Y2 - 10 June 2012 through 15 June 2012
ER -
