Exploring Spatial Focusing Effect for Spectrum Sharing and Network Association
Next-generation wireless networks are expected to support an exponentially increasing number of users and demands of data, which all rely on the essential media: spectrum. Spectrum sharing among heterogeneous networks is a fundamental issue that determines network performance. Previous works have focused on a “dynamic spectrum access” mode associated with the cognitive radio technology. These works all focused on the discovery of available spectrum resource either in the time domain or in the frequency domain, i.e., by separating different users’ transmission. To initiate a new paradigm of spectrum sharing, the unique characteristics of the technologies should be utilized in the next-generation networks. The 5G networks are featured either by wide bandwidth like mm-wave systems, or by large-scale antennas like massive MIMO. Those two trends can lead to a common phenomenon: the spatial focusing effect. Based on this focusing effect, we propose a general spatial spectrum sharing framework that enables concurrent multi-users spectrum sharing without the requirement of orthogonal resource allocation. Moreover, we design two general network association protocols either in a centralized manner or in a distributed manner. Simulation results show that both the time reversal wideband and the massive MIMO system can achieve high throughput performance with the spatial spectrum sharing scheme.