Optimization of Layer Selection with Unreliable RI in LTE Systems

Authors

  • Weidong Zhang Key Laboratory of Universal Wireless Communications, Beijing University of Posts and Telecommunications, Beijing 100876
  • Ying Wang Key Laboratory of Universal Wireless Communications, Beijing University of Posts and Telecommunications, Beijing 100876
  • Mingyue Xu Key Laboratory of Universal Wireless Communications, Beijing University of Posts and Telecommunications, Beijing 100876
  • Cong Shi Key Laboratory of Universal Wireless Communications, Beijing University of Posts and Telecommunications, Beijing 100876
  • Ping Zhang Key Laboratory of Universal Wireless Communications, Beijing University of Posts and Telecommunications, Beijing 100876

Keywords:

LTE, MIMO, RI, transmission spatial layer, BLER, ATC algorithm, CQI adjustment

Abstract

This paper investigates the optimization of transmission spatial layer selection with unreliable rank indicator (RI) in downlink LTE systems. Taking the block error rate (BLER) into consideration, we propose an accurate throughput calculation (ATC) algorithm at user equipment (UE) side as well as at evolved NodeB (eNB) side. On the basis of ATC algorithm, we propose an accurate RI selection algorithm to periodically choose the preferred number of transmission spatial layers at UE side. Further based on acknowledgement (ACK)/ negative acknowledgement (NACK) history, channel quality indicator (CQI) is adjusted at eNB side to achieve the throughput optimal target BLER. By substituting the derived BLER into ATC algorithm, the optimal number of transmitted spatial layers in current downlink channel is derived at eNB side. Simulation results show that both the proposed CQI adjustment scheme for spatial layer selection and RI selection algorithm yield up significant throughput improvement for different evaluation scenarios in LTE systems.

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Author Biographies

Weidong Zhang, Key Laboratory of Universal Wireless Communications, Beijing University of Posts and Telecommunications, Beijing 100876

Weidong Zhang received the B.S. degree in Telecommunication Engineering from Beijing University of Posts and Telecommunications (BUPT) in 2008. Now he is working toward his Ph.D. degree in the field of Telecommunication and Information System in Wireless Technology Innovation Institute, BUPT. His research interests include femtocell technology, MIMO and dynamic radio resource management in future wireless networks.

Ying Wang, Key Laboratory of Universal Wireless Communications, Beijing University of Posts and Telecommunications, Beijing 100876

Ying Wang received the B.S. degree and M.S. degree in Electronics Engineering from Northwestern Polytechnical University in 1998 and 2000 respectively, and her Ph. D. in circuits and systems from Beijing University of Posts and Telecommunications (BUPT) in 2003. From Jan. 2004 to Mar. 2004, she was invited to work as a visiting researcher in Communications Research Laboratory (renamed NiCT from Apr. 2004), Yokosuka, Japan. And in 2005, she worked as a research associate in The University of Hong Kong. Now she is a professor of BUPT and a researcher of Wireless Technology Innovation Institute. Her research interests are in the area of the cooperative relaying system, radio resource management and mobility management in the Beyond 3G and 3G systems.

Mingyue Xu, Key Laboratory of Universal Wireless Communications, Beijing University of Posts and Telecommunications, Beijing 100876

Mingyue Xu received the B.S. degree in Telecommunication Engineering from Beijing University of Posts and Telecommunications (BUPT) in 2010. Now she is working in the field of Telecommunication and Information System in Wireless Technology Innovation Institute, BUPT. Her research interests include relay technology, MIMO and cognitive radio systems.

Cong Shi, Key Laboratory of Universal Wireless Communications, Beijing University of Posts and Telecommunications, Beijing 100876

Cong Shi received the B.S. degree in Electronic Engineering from Xidian University, China, in 2008. Now he is working toward his Ph.D. degree in the field of Telecommunication and Information System in Wireless Technology Innovation Institute, Beijing University of Posts and Telecommunications (BUPT). His research interests include MIMO-OFDM techniques and dynamic resource allocation in future wireless networks.

Ping Zhang, Key Laboratory of Universal Wireless Communications, Beijing University of Posts and Telecommunications, Beijing 100876

Ping Zhang received the M.S. degree from Northwest Polytechnic University, Xian, China, in 1986 and the Ph.D. degree from Beijing University of Posts and Telecommunications (BUPT), Beijing, China, in 1990, both in electrical engineering. From 1994 to 1995, he was a Post-Doctoral Researcher in the PCS Department, Korea Telecom Wireless System Development Center. Now he is a professor of BUPT, director of Wireless Technology Innovation Institute, member of China 3G and B3G group. His research interests cover key techniques of Beyond 3G and 3G systems, including MIMO-OFDM, radio resource management and cognitive radio.

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Published

2014-06-27

How to Cite

Zhang, W., Wang, Y., Xu, M., Shi, C., & Zhang, P. (2014). Optimization of Layer Selection with Unreliable RI in LTE Systems. COMPUTING AND INFORMATICS, 33(2), 431–445. Retrieved from http://www.cai.sk/ojs/index.php/cai/article/view/841