Group based pairing scheduling for VMIMO up link in femtocell systems

Abstract

Multi-Input Multi-Output (MIMO) techniques provide extra-ordinary improvements in system throughput and robustness performance. But for mobile communication such MIMO benefits require un-correlated signal paths which impose constraints on minimum spacing between antennas on mobile nodes. Thus the future of mobile communication lies in Virtual-MIMO (VMIMO) which schedules and allows multiple mobile nodes to simultaneously use single Resource Block (RB). Need for higher data-rate and ubiquitous coverage drive the development and research of wireless communications. Current user trend is shifting towards massive mobile use within indoors for multi media, socializing and video calling applications. Unlike traditional internet use, such applications generally uniform uplink and downlink traffic. The appropriate and flexible solution for such constraints is the Femtocell architecture which provides indoor coverage and capacity improvement while being back hauled by general internet connection. Femtocell architecture provides suitable scenario for VMIMO application but it puts additional constraints in terms of VMIMO scheduling. In addition to general requirement of throughput-fairness balance, Femtocell environment requires that all the users be ensured service. The presented thesis proposes a Proportional Fairness Grouped Scheduling (PFGS) which groups users according to proportional fairness ranking and assigns them RB accordingly. The presented thesis provides performance analysis of the proposed algorithm in terms of both throughput and fairness and analyzes the improvement as compared to traditional algorithms. The proposed algorithm is also tested and reported in terms of flexibility with regards to number of active users, number of RB and number of antennas available at the Base Transceiver Station (BTS).