Optimal decoding order under target rate constraints

In this contribution, we derive the optimal power allocation under target rate constraints in the case of an uplink multiuser system. Using asymptotic results based on random matrix theory, we provide a unified framework for determining the optimal decoding order when using Successive Interference Cancellation (SIC) receivers, namely the MMSE (Minimum Mean Square Error) and Matched filter SIC. Moreover, for decentralized systems, we show that each user can, under certain conditions, solely determine the power allocation based only on his channel energy and the statistics of the other users. Simulations in the case of finite systems validate the asymptotic claims.