Joint scheduling and resource allocation based on genetic algorithm for coordinated multi-point transmission using adaptive modulation

This paper considers the scheduling and resource allocation with adaptive modulation in downlink coordinated multi-point transmission (CoMP) systems, where multiple users are served via zero-forcing precoding simultaneously by several cooperative base stations (BSs). The joint scheduling and resource allocation to maximize the sum rate is formulated as a combinational optimization problem under constraints. As the searching space for this problem is extremely large, which prohibits an exhaustive search (ES), a genetic algorithm (GA) based solution is proposed. In particular, a two-dimension-binary chromosome coding scheme is designed to denote potential user selection and bit loading strategies across multiple subchannels. To handle per-BS power constraint, a penalty based fitness function is used, and in doing so GA can search for optimal solution in a larger region. To ensure convergence, a super individual named elite is added to each population. Simulation results indicate that the proposed algorithm leads to significant sum rate gain compared to existing schemes, and provides close to ES performance but with much lower computational complexity.