Adaptive Power Allocation for Multi-hop OFDM System with Non-regenerative Relaying

This paper aims to improve capacity in multi-hop OFDM system with non-regenerative relaying based on power allocation. The capacity model is presented, power allocation is analyzed based on the subsignal tuned to subcarrier of OFDM. Power allocation is decomposed to two subproblems. The first subproblem is the optimal power allocation to every hop of subsignal, when the power of each subsignal is fixed, an algorithm with low computing complexity is expressed to get optimal solution. The second subproblem is the power allocation to every subsignal, a suboptimal greedy algorithm is proposed based on the solution from the first subproblem. Compared with the usual equal power allocation method, the simulation result shows that proposed power allocation could improve system capacity greatly. With the subcarrier selection expressed in this paper, the system capacity is further improved.