Reference Point MCDM Algorithm for Spectral and Energy Efficiency Trade-Off in Massive MIMO Systems

This paper proposes a new algorithm for choosing a solution in the Pareto Optimal Front of the multi-objective optimization problem of the spectral and energy efficiency trade-off in Massive MIMO ( Multiple-Input, Multiple-Output ) systems. The new method is based on the weights assigned to each objective, which are used to calculate a reference point. The solution chosen by the algorithm is the solution that has the shortest distance from the reference point. The algorithm is able to explore the whole Pareto Front in both its concave and convex parts, but it has a flaw, which is that it is highly impacted by the range of values of the objectives. This limitation of the algorithm can be solved by normalizing the Pareto Front, so that the values for all of the criteria are numbers from 0 to 1, or by using the cosine similarity to measure the distance of the solutions from the reference point. Simulations show that after implementing one of the two methods that make the algorithm independent of the range of the values of the objectives, it performs well by choosing solutions with an optimal distribution throughout the whole Pareto Front.