Power efficient 60 GHz wireless communication networks with relays

In this paper, we study the power consumption in relay networks of the 60 GHz wireless communication based on amplify-and-forward (AF) and decode-and-forward (DF) relaying strategies. We propose a total power consumption model including drive power, decoding power, and power consumption of power amplifier (PA). This model is formulated as a function of drive power, which gives an easy access to the system level optimisation. The optimal drive power that minimises the total power consumption while satisfying the performance requirement can be found by numerical searching method. The impact of relay's locations on the total power consumption is also investigated. We show that, with the same performance requirement, in the small source-relay separation case AF consumes less power than DF, while with larger separation, AF consumes significantly more power than DF. This is different from the common intuition that DF is always more power consuming than AF due to the extra decoding power consumption at relay, which is due to the fact that the large source-relay separation limits the effective destination signal-to-noise ratio (SNR) in AF, leading to more substantial decoding power consumption in the many more decoding iterations than DF.