The effect of energy efficiency and spectrum efficiency on bit error rate for unidirectional relay networks

A new method to analyze Energy Efficiency (EE) verse Bit Error Rate (BER) in AF relay networks is presented in this paper. In this network, the source transmits signals through flat fading channels to a set of intermediate relay nodes which amplify signals and then forwards them to the destination through other flat fading channels. The proposed EE is derived in a balanced scheme with Spectrum Efficiency (SE), when relay location is considered. Such a balance between EE and SE is achieved by minimizing power consumption. Furthermore, the BER for this balance is analyzed and the relationship between BER and EE is derived. All analytical expressions are validated numerically by simulation.