ABSTRACT
Singapore University of Technology and Design, and Institute for Infocomm Re-
search, Singapore
Zhongding Lei
Institute for Infocomm Research, Singapore
5.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144 5.2 System Model and Problem Formulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146
5.2.1 System Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146 5.2.2 Problem Formulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148
5.3 Reweighted ℓ1-Norm Minimization-Based Method . . . . . . . . . . . . . . . . . . 149 5.4 Iterative Link Removal-Based Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152
5.4.1 ℓ2-Norm Relaxation of Joint Clustering and Beamforming . . 153 5.4.2 Iterative Link Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157 5.4.3 Implementation Issues . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158 5.4.4 Complexity Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159
5.5 Simulation Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160 5.5.1 Convergence Behavior . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160 5.5.2 Cellular Network Simulations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161
5.6 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 169
Coordinated Multipoint (CoMP) transmission has been incorporated into the latest
3GPP LTE-Advanced releases to combat the intercell interference (ICI) and im-
prove the signal quality of cell edge users in multicell wireless systems [1]. The
idea is to aggregate neighboring base stations (BSs) and form the CoMP cooperat-
ing set. Transmission strategies for the BSs within this set are coordinated to effec-
tively mitigate the interference at the mobile stations (MSs). Coordinated schedul-
ing/beamforming (CS/CB) and joint transmission (JT) are the two major approaches
in CoMP [2]. In the CS/CB approach, the data stream for each MS is only avail-
able at and transmitted from a single BS; however, the user data for each MS can
be distributed to multiple cooperating BSs in the JT approach and be simultaneously
transmitted from them.