Cell selection for range expansion with almost blank subframe in heterogeneous networks

• Published in: 2012 IEEE 23rd International Symposium on Personal, Indoor and Mobile Radio Communications - (PIMRC) pp. 653 - 657
• Main Authors: Jinyoung Oh, Youngnam Han
• Format: Conference Proceeding
• Language: English
• Published: IEEE 01.09.2012
• Subjects: Interference; Macrocell networks; Signal to noise ratio; Simulation; Throughput; Wireless communication
• ISBN: 9781467325660; 146732566X
• ISSN: 2166-9570
• DOI: 10.1109/PIMRC.2012.6362865

To encourage data offloading in heterogeneous networks, range expansion techniques have been introduced in LTE-Advanced system. By adding a positive bias in cell selection process, more users can select picocells as their serving cells even the picocell is not of the strongest signal. Also, to protect offloaded users from severe macrocell interference, a specific subframe called almost blank subframe (ABS) is introduced. Since macrocell is kept silent during ABSs, the offloaded users can be allocated without strong macrocell interference within ABSs. It is noted that the offloaded user's average data rate highly depends on the amount of ABSs rather than the bias value because the scheduling opportunities of offloaded users are limited within ABSs. And from the user's point of view, the cell which is expected to give high data rate should be selected as a serving cell. In this paper, we propose a cell selection scheme based on expected user data rate which is a function of the ABS ratio. Simulation results show that the performance of our proposed cell selection scheme can improve average user rate and increase the number of offloaded users as the ABS ratio increases.