DECOMPOSITION AIDED PRECODER DESIGN FOR ENERGY EFFICIENCY IMPROVEMENT IN mmWAVE MIMO SYSTEM

The emergence of high data applications and limited bandwidth availability in the sub-6 GHz band promotes the need for larger bandwidth operation. Millimeter waves provide a viable solution for providing wider bandwidth and requires large antenna array. This large antenna array utilizes large number of RF chains which increases the complexity and cost of mmWave systems. Multiple antennas are often connected to a single beam source to avoid interference. Multi-beam transmission promotes maximal capacity at the expense of energy efficiency. Three decomposition-aided methods for adaptive RF chain activation in a multi-beam multi-RF mmWave system are proposed. To improve the energy efficiency, a maximal gain aligned precoder design over the decomposition methods were proposed. The sum rate, energy efficiency, and computational complexity of the proposed methods were analyzed.