Known Interference in the Cellular Downlink: A Performance Limiting Factor or a Source of Green Signal Power?

Interference in wireless communications is traditionally treated as a cause of performance degradation. Whilst from a statistical viewpoint this is entirely justified, this article discusses scenarios where the interfering signal enhances the desired signal's useful power on an instantaneous basis and provides an unexplored source of additional signal power. The potential of harvesting this energy, which naturally exists in the communication system, is shown to be readily available in downlink systems where interference can be predicted. The main concept discussed is that instead of using knowledge of the interference to cancel, eliminate or avoid it, it is potentially more fruitful to use this knowledge to manipulate and make use of the interference towards the system's advantage. A significant source of useful signal power, which with conventional transmission techniques is left unexploited, can be used to improve the radio systems' performance and achieve reliable power-efficient communications where performance benefits are yielded without the need to increase the average transmitted power.