Millimeter-Wave Downlink Coverage Extension Strategies

Traditionally, the uplink and downlink in a cellular network are associated with the same base station and the same frequency band since it promotes simpler network design, maintenance, and operation because of reduced complexity. However, when deploying millimeter-wave (mmWave) spectrum, network coverage has limitations hinging on the nature of the mmWave propagation characteristics relative to the traditional sub 6 GHz frequency bands. In this article, we present a method for an extension of the mmWave downlink coverage by demonstrating the benefits of decoupling the reverse and forward link frequencies and by leveraging macro-type radio deployment heights to maximize the line-of-sight coverage. The accompanying link budget analysis and coverage simulations quantify the benefit of the coverage extension methodology to be as much as 6.8 dB while extending possible coverage range distance to greater than 2 km.