Energy-Efficient Power Allocation for the Downlink of a Multi-Cell Multi-User MIMO System with Block Diagonalization

Optimization in mobile communications has mostly been performed based on spectral efficiency (SE). However, energy efficiency (EE) is fast becoming a key performance indicator, together with SE for designing future networks. In multi-cell communications, other-cell interference (OCI) coming from neighboring cells degrades both the SE and EE performances of the system. This paper presents an energy efficient precoding/power allocation algorithm for the downlink of the multi-cell multi-user multi-antenna channel, based on block diagonalization (BD). Each user employs an interference suppression filter while the precoder uses information about OCI plus noise covariance matrix to cancel interference and perform power allocation in an energy efficient manner. Simulation results show that our energy efficient BD scheme reduces the power consumption of the system and improves the EE in comparison with existing SE-based BD scheme