Decentralized Femtocell Transmission Regulation in Spectrum-Sharing Macro and Femto Networks

Due to considerations of spectrum availability and network infrastructure, existing macrocell networks may have to share the spectrum with overlaid femtocells. In spectrum-sharing macro and femto networks, different transmit powers used by macro base stations (MBS) and femto access points, together with potentially densely deployed femtocells, may create dead spots where reliable coverage cannot be guaranteed to either macro or femto users. In this paper, we devise a decentralized strategy to regulate femtocell management of transmit power and usage of radio resources depending on its distance from the closest MBS. Simulation results for the orthogonal frequency division multiple access (OFDMA) downlink (DL) of spectrum-sharing macro and femto networks show that the proposed decentralized femtocell regulating strategy is able to guarantee reliable DL coverage over targeted macro and femto service areas while providing superior spatial spectrum reuse, for even a large number of spectrum-sharing femtocells deployed per cell site.