Energy Efficiency Tradeoff in Interference Channels

Interference is one of the major obstacles to improving the performance in wireless communication systems. As the ever-growing data traffic is carried over extremely dense networks, how to deal with interference becomes even more relevant. In this paper, we investigate a network with N pairs of users transmitting on the same channel simultaneously from the energy efficiency (EE) perspective. For such an interference network, we aim to address two issues: what is the EE tradeoff between users and how to design energy-efficient resource allocation scheme? To answer these two questions, we formulate a non-concave multi-objective optimization problem (MOOP) to investigate the EE tradeoff, taking into account the minimum data rate requirement of each user. The weighted Tchebycheff method is utilized to solve the MOOP by converting it into a single-objective optimization problem, which is then solved by the Dinkelbach method and the concave-convex procedure method. Based on the above, a power control algorithm is developed for the interference network to achieve at least a local optimum. The proposed algorithm is compared with the orthogonal bandwidth sharing, where each user orthogonally shares the whole bandwidth without interfering each other. In this scenario, the weighted Tchebycheff and the Dinkelbach methods are also utilized to develop the optimal bandwidth allocation and power control algorithm. The performance of the proposed algorithms is verified by numerical results, which show that it is better to share the bandwidth orthogonally rather than non-orthogonally if the interference between each user pair is stronger than a given threshold.