Capacity Bound And Power Allocation Of Relay Channel With MIP-QF Strategy

With the development of wireless communication,cooperative communication is playing an increasingly important role,and the relay technology is an important part of cooperative communication.In order to overcome the synchronous problem,half-duplex relay technology becomes more and more popular.Recently,a new mutual information preserving quantize-and-forward(MIP-QF)strategy is proposed for the half-duplex relay channel.The computational complexity of the strategy is lower,and it can achieve higher spectrum efficiency and lower bit error rate(BER).In this paper,we focus on the capacity bound and power allocation of the MIP-QF strategy in the half-duplex relay channel.Firstly,a new upper bound of MIP-QF strategy named MIP-QF bound in half-duplex relay channel is proposed,and an achievable rate in the Additive White Gauss Noise(AWGN)relay channel is presented.Then,we compare the MIP-QF bound with some classical capacity bounds including the Cut-Set bound,the Compress-Forward(CF)bound and the Decode-Forward(DF)bound.We get the conclusion that the MIP-QF bound lies between the Cut-Set bound and the CF bound.In some special cases,the DF bound can exceed MIP-QF bound.We also extend the conclusion to the half-duplex Multiple Access Relay Channel(MARC).Finally some numerical and simulation results are given under the AWGN relay channel to verify the accuracy of proposed theoretical results.Reasonable power allocation makes the system reach a higher achievable rate,so the second part focuses on the research of power allocation based on the MIP-QF and CF strategy.Firstly,the time duplex ratios are optimized with Lagrange Multiplier method for the two strategies.We get the optimal time duplex ratios when the power of each node is known with the target of maximum achievable rate.Secondly,power allocation between source and relay for the two strategies is completed.When the power of first time slot and last time slot are given,we give optimal power allocation results between source and relay to maximize the achievable rates with Lagrange Multiplier method.Thirdly,when the total power is known,we can give optimal power allocation results for each node to maximize the achievable rates for the two strategies.At last,we give some simulation results to compare the theoretical results with numerical results under the half-duplex AWGN relay channel.And some comparison figures between theoretical and numerical results are givento verify the accuracy of proposed theoretical results.