When Is the Achievable Rate Region Convex in Two-User Massive MIMO Systems?

Zheng Chen; Emil Björnson; Erik G. Larsson

doi:10.1109/lwc.2018.2825443

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arXiv · 1806.07178

When Is the Achievable Rate Region Convex in Two-User Massive MIMO Systems?

Zheng Chen·Emil Björnson·Erik G. Larsson

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Abstract

This letter investigates the achievable rate region in Massive multiple-input-multiple-output (MIMO) systems with two users, with focus on the i.i.d.~Rayleigh fading and line-of-sight (LoS) scenarios. If the rate region is convex, spatial multiplexing is preferable to orthogonal scheduling, while the opposite is true for non-convex regions. We prove that the uplink and downlink rate regions with i.i.d.~Rayleigh fading are convex, while the convexity in LoS depends on parameters such as angular user separation, number of antennas, and signal-to-noise ratio (SNR).

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Zheng Chen, Emil Björnson, Erik G. Larsson. 2018-06-19. When Is the Achievable Rate Region Convex in Two-User Massive MIMO Systems?. https://doi.org/10.1109/lwc.2018.2825443

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