Resource Allocation in Spectrum-Sharing OFDMA Femtocells With Heterogeneous Services

• Published in: IEEE transactions on communications Vol. 62; no. 7; pp. 2366 - 2377
• Main Authors: Haijun Zhang, Chunxiao Jiang, Beaulieu, Norman C., Xiaoli Chu, Xiangming Wen, Meixia Tao
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.07.2014; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Algorithms; Allocations; Applied sciences; Cellular communication; Computational efficiency; Educational institutions; Exact sciences and technology; Femtocells; Information, signal and communications theory; Integer programming; Interference; Macrocell networks; Multiplexing; Operation, maintenance, reliability; Optimization; Programming; Quality of service; Resource allocation; Resource management; Signal and communications theory; Systems, networks and services of telecommunications; Telecommunications; Telecommunications and information theory; Transmission and modulation (techniques and equipments); Uplink; resource allocation; OFDMA; femtocell; Convex optimization; heterogeneous services; Performance evaluation; Wireless telecommunication; Resource allocation; Decomposition method; Frequency division multiple access; Downlink; Updating; Iterative method; Power allocation; Convex programming; Indoor installation; User service; Delay time; Uplink; Mixed integer programming; Coverage; Resource sharing; Algorithm; Channel allocation; Orthogonal frequency division multiplexing; Service quality
• ISSN: 0090-6778; 1558-0857
• DOI: 10.1109/TCOMM.2014.2328574

Femtocells are being considered a promising technique to improve the capacity and coverage for indoor wireless users. However, the cross-tier interference in the spectrum-sharing deployment of femtocells can degrade the system performance seriously. The resource allocation problem in both the uplink and the downlink for two-tier networks comprising spectrum-sharing femtocells and macrocells is investigated. A resource allocation scheme for cochannel femtocells is proposed, aiming to maximize the capacity for both delay-sensitive users and delay-tolerant users subject to the delay-sensitive users' quality-of-service constraint and an interference constraint imposed by the macrocell. The subchannel and power allocation problem is modeled as a mixed-integer programming problem, and then, it is transformed into a convex optimization problem by relaxing subchannel sharing; finally, it is solved by the dual decomposition method. Subsequently, an iterative subchannel and power allocation algorithm considering heterogeneous services and cross-tier interference is proposed for the problem using the subgradient update. A practical low-complexity distributed subchannel and power allocation algorithm is developed to reduce the computational cost. The complexity of the proposed algorithms is analyzed, and the effectiveness of the proposed algorithms is verified by simulations.