Scaling Laws of Dense Multi-Antenna Cellular Networks
We study the scaling laws of the signal-to-interference-plus-noise ratio (SINR) and the area spectral efficiency (ASE) in multi-antenna cellular networks, where the number of antennas scales with the base station (BS) spatial density λ. We start with the MISO case with N_t(λ) transmit antennas and a single receive antenna and prove that the average SINR scales as N_t(λ)/λ and the average ASE scales as λlog(1+N_t(λ)/λ). For the MIMO case with single-stream eigenbeamforming and N_r(λ) ≤ N_t(λ) receive antennas, we prove that the scaling laws of the conditional SINR and ASE are agnostic to N_r(λ) and scale exactly the same as the MISO case. Hence, deploying multi-antenna BSs can help maintain non-zero per-user throughput and a corresponding linear increase in the ASE in dense cellular networks.
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