Coverage and Capacity performance of mmWave MIMO System at 28 GHz and 60 GHz for Wireless Local Area Network under Line-of-Sight (LOS) and Non-Line-of-Sight (NLOS)

This study presents a comprehensive simulation-based analysis of the coverage and capacity performance of mmWave MIMO systems operating at 28 GHz and 60 GHz under both Line-of-Sight (LOS) and Non-Line-of-Sight (NLOS) conditions. The results reveal that 28 GHz provides more stable and broader coverage due to lower path loss, while 60 GHz achieves higher peak capacities in short-range LOS environments because of its wider bandwidth. In LOS scenarios, both frequencies demonstrate strong Received Signal Strength Indicator (RSSI) and Signal-to-Noise Ratio (SNR), with 60 GHz showing superior throughput at short distances. However, the advantages of 60 GHz diminish sharply in NLOS conditions, where RSSI and SNR drop significantly, often resulting in link degradation or loss, highlighting its sensitivity to obstructions and atmospheric absorption. Further analysis of channel capacity versus distance and frequency confirms the inherent trade-offs in mmWave deployment. At increasing distances, especially beyond 10 meters, both frequencies experience rapid SNR decline and capacity reduction due to high free-space path loss. Notably, 28 GHz maintains usable SNR and capacity over longer distances, making it more suitable for broader-area communication networks. In contrast, 60 GHz’s capacity advantage is confined to short-range, interference-free environments. Environmental factors such as indoor office walls and dense urban structures further exacerbate signal degradation at 60 GHz, significantly affecting link reliability in NLOS settings. Beam forming techniques partially mitigate these losses but are not always sufficient to sustain connectivity. Overall, the findings emphasize the importance of frequency selection and environmental considerations in designing high-performance mmWave wireless systems. While 60 GHz offers exceptional data rates in controlled LOS environments, it requires dense access point deployment and sophisticated signal processing to counteract its limited coverage. Conversely, 28 GHz strikes a balance between capacity and reliability, providing more robust performance across varied indoor and outdoor scenarios. The results support the strategic use of hybrid mmWave deployments that combine the strengths of both frequency bands, tailored to specific application needs and propagation environments.