Sum-Rate Capacity of Random Beamforming for Multi-Antenna Broadcast Channels with Other Cell Interference

• Published in: IEEE transactions on wireless communications Vol. 10; no. 8; pp. 2440 - 2444
• Main Authors: MOON, Sung-Hyun, LEE, Sang-Rim, LEE, Inkyu
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.08.2011; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Antennas; Applied sciences; Approximation methods; Array signal processing; Asymptotic properties; Beamforming; Channels; Constraining; Detection, estimation, filtering, equalization, prediction; Downlink; Exact sciences and technology; Gain; Information, signal and communications theory; Interference; MIMO; MIMO broadcast channel; multiuser scheduling; other-cell interference; Radiocommunications; random beamforming; Signal and communications theory; Signal to noise ratio; Signal, noise; Simulation; Systems, networks and services of telecommunications; Telecommunications; Telecommunications and information theory; Transmission and modulation (techniques and equipments); Wireless communication; MIMO system; random beamforming; Multiple access; Channel capacity; Broadcast antennas; multiuser scheduling; Downlink; Ergodicity; Scheduling; Beam forming; Radial basis function; Scaling law; Simulation; Extreme value; MIMO broadcast channel; other-cell interference; Signal processing; Broadcast channels; Signal to interference plus noise ratio
• ISSN: 1536-1276; 1558-2248
• DOI: 10.1109/TWC.2011.070711.102145

In this letter, we analyze the sum rate of random beamforming (RBF) for downlink multi-antenna systems in the presence of other cell interference (OCI). Employing extreme value theory, an expression of the asymptotic ergodic sum rate with a large number of users is derived from the limiting distribution of the sample maximum of the received signal-to-interference-plus-noise ratio. Based on our result, the scaling law of multiuser diversity gain is also exhibited in the context of RBF systems with the OCI, which is shown to coincide with the previous result without the other cell interferers. Simulation results verify the validity of our analysis even with not so large number of users.