TRANSACTIONS ON EMERGING TELECOMMUNICATIONS TECHNOLOGIES Trans. Emerging Tel. Tech. 2014; 25:707–722 Published online 26 November 2012 in Wiley Online Library (wileyonlinelibrary.com). DOI: 10.1002/ett.2599 RESEARCH ARTICLE Network planning for distributed antenna-based high-speed railway mobile communications Jin-Yuan Wang 1,2 , Jun-Bo Wang 3,4 *, Xiaoyu Song 5 , Ming Chen 1 and Jie Zhang 6 1 National Mobile Communications Research Laboratory, Southeast University, Nanjing 210096, China 2 State Key Laboratory of Integrated Services Networks, Xidian University, Xi’an 710071, China 3 College of Electronic and Information Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China 4 Key Laboratory for Information System Security of Ministry of Education, School of Software, Tsinghua University, Beijing 100084, China 5 Department of Electrical and Computer Engineering, Portland State University, PO Box 751, Portland, OR, USA 6 College of Information Science and Technology, Beijing University of Chemical Technology, Beijing 100029, China ABSTRACT Network planning in wireless communication systems, which has strong impacts on the system performance, is a complex and challenging issue. This paper investigates the network planning problem under high-speed railway communication scenarios. A system model is characterised in terms of distributed antenna technology. An optimisation problem is formulated to optimise the total system cost with transmission rate, handoff time and antenna number constraints. Because the optimisation problem is NP-hard, a particle swarm optimisation (PSO)-based network planning strategy is proposed to tackle it. The complexity analysis demonstrates the effectiveness of the proposed PSO-based network planning scheme in terms of running time and memory space. Finally, the simulation results substantiate that the proposed method can consistently offer a better performance gain in comparison with the uniform network planning scheme. Copyright © 2012 John Wiley & Sons, Ltd. KEY WORDS network planning; high-speed railway; distributed antenna; particle swarm optimisation; computational complexity *Correspondence Jun-Bo Wang, College of Electronic and Information Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China. E-mail: jbwang@nuaa.edu.cn Received 14 March 2012; Revised 27 September 2012; Accepted 10 October 2012 1. INTRODUCTION Railway plays a crucial role in public transportation sys- tems nowadays. Recently, the high-speed railway, which can provide a relatively convenience and stable environ- ment, has made a vigorous development all over the world [1]. To provide diversified services to train passengers, a railway communication system with a high level of qual- ity of service (QoS) is desired. However, the network architecture, hardware devices and software algorithms in present railway communication systems have been unable to match with the higher technical requirements (such as over-frequent handoff, Doppler frequency shift and chan- nel fast variation) under high-speed environment, which will lead to a severe decrease in terms of system perfor- mance. Therefore, there is a strong demand to exploit a new network structure for the next generation high-speed railway mobile communication systems. Although it has been developing very rapidly [2–6] from code division multiple access to orthogonal frequency divi- sion multiple access techniques, wireless mobile commu- nication suffers from severe multipath fading and path loss. Currently, the distributed antenna technology has drawn extensive attention [7–9]. In distributed antenna systems (DAS), multiple antennas are geographically distributed to reduce access distance instead of centralising at a location. No sophisticated signal processing techniques are carried out at those antennas so that their size and cost decrease and can be installed like street lamps every few hundred metres [10]. At the central processing unit, the signals associated with different connected distributed antennas are processed by all kinds of advanced signal process- ing techniques. Each distributed antenna in DAS is con- nected to the central processing unit via dedicated wires, optical fibres or an exclusive radio frequency link. By employing distributed antenna technology, each mobile Copyright © 2012 John Wiley & Sons, Ltd. 707