High-altitude platform station (HAPS) is a promising technology for extending the coverage of cellular networks. For multi-HAPS scenarios in which multiple HAPSs use a single shared frequency band to communicate with terrestrial users in their service areas, the interference between neighboring HAPSs is a concerning issue that degrades the overall system capacity in service links. Accordingly, this study proposes a novel two-stage precoding scheme for massive multiple-input and multiple-output systems with a large-scale cylindrical array antenna to mitigate the interference with the neighboring service areas covered by other HAPSs. The proposed scheme comprises outer and inner precoders; the outer precoder reduces the interference with other service areas via subarray grouping and nullforming, whereas the inner precoder generates user-specific beams. Results show that the proposed precoders improve the signal-to-interference-plus-noise ratio of terrestrial users by up to 6.8 dB in a multi-HAPS scenario compared to a conventional fully-connected zero-forcing precoder without any interference reduction techniques.
Interference Reduction between HAPSs using Subarray Grouping and Nullforming Techniques for Cylindrical Massive MIMO Systems
01.06.2023
3115773 byte
Aufsatz (Konferenz)
Elektronische Ressource
Englisch
Frobenius Norm Based Receive Antenna Subarray Formation for MIMO Systems
British Library Conference Proceedings | 2006
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