In LTE (Long Term Evolution) and a successor system (for example, also referred to as LTE-Advanced, FRA (Future Radio Access), 4G and the like) to LTE, radio communication systems (for example, also referred to as Heterogeneous network) have been studied in which a small cell (including a picocell, femtocell and the like) having relatively small coverage with a radius of about several meters to several tens of meters is arranged, while overlapping a macrocell having relatively large coverage with a radius of about several hundreds of meters to several kilometers (for example, Non-patent Literature 1).
In such a radio communication system are studied a scenario (for example, also referred to as co-channel) using the same frequency band in both the macrocell and the small call, and another scenario (for example, also referred to as separate frequency) using different frequency bands in the macrocell and the small cell. More specifically, in the latter scenario, it is studied that a relatively low frequency band (for example, 2 GHz) is used in the macrocell, and that a relatively high frequency band (for example, 3.5 GHz, 10 GHz and the like) is used in the small cell.
USPTO Backgrounds
USPTO Backgrounds