Power VS energy efficiency conflict and its solution by cognitive radio in green communication

In this paper, we introduce the problem that occur in the current communication system— the issue of large energy consumption to support the spectrum efficiency, which has a negative impact on our environment. And such fact has been confirmed by theoretical formulas. Under such severe situation, a surmise has been raised to solve the conflict between spectrum and power efficiency—strike a balance between the two—that is to find a trade-off. Finally, by applying cognitive radio technology, the power consumption is reduced by allowing flexible usage of spectrum, which has confirmed the surmise. At last, we have proposed a new perspective to further approach to the definition of green efficiency of green communication, which is useful in identifying a new way to resolve the conflict between the power and spectrum efficiency in the future.