Optimal Power Allocation with Hybrid Relaying Based on the Channel Condition

The simulation results show that the proposed optimal power allocation scheme requires lower transmit power to achieve a specific achievable rate than the equal power allocation scheme. [...]this paper contributes to a reduction in the lower limit of transmit power consumption to satisfy the achievable rate in cooperative communication. The operation of addition, subtraction, or comparison is expressed as O. From the algorithm for the DF-AF relay network in Figure 3, the complexity to find αda can be calculated as 9O2+10O . Because the proposed optimal power allocation schemes provide the closed form-based formula, the complexity of the proposed schemes is much less than for the grid search schemes. [...]the advantage of proposed schemes increases linearly according to the bandwidth of systems. Since the bandwidth of recent communication systems has been increased continuously to accommodate future data traffic, the proposed optimal allocation scheme can contribute to increase the power efficiency of the recent wideband systems. [...]the achievable rate of DF-AF relay network is greater than that of the AF-DF relay network when the channel gain between the second relay and destination is higher than that between two relays. [...]we can consider this an appropriate hybrid relaying scheme with optimal power allocation which enables us to provide the best performance in given channel conditions.