Decentralized Fair Scheduling in Two-Hop Relay-Assisted Cognitive OFDMA Systems

Date Added: Jun 2010
Format: PDF

In this paper, the authors consider a two-hop relay-assisted cognitive downlink OFDMA system (named as secondary system) dynamically accessing a spectrum licensed to a primary network, thereby improving the efficiency of spectrum usage. A cluster-based relay-assisted architecture is proposed for the secondary system, where relay stations are employed for minimizing the interference to the users in the primary network and achieving fairness for cell-edge users. Based on this architecture, an asymptotically optimal solution is derived for jointly controlling data rates, transmission power, and sub-channel allocation to optimize the average weighted sum good-put where the Proportional Fair Scheduling (PFS) is included as a special case.