Optimal Power Allocation in Zero-forcing MIMO-OFDM Downlink with Multiuser Diversity
نویسندگان
چکیده
This paper considers the optimal power allocation for a multiuser MIMO-OFDM downlink system using zero-forcing multiplexing, with the objective to maximize the system capacity. First, we consider the problem of user selection and power allocation for every subcarrier. By converting this combinatorial optimization problem into a convex one, an optimal power allocation algorithm has been derived. Then we introduce and formulate two new problems by extending user selection to antenna selection and dimension selection. We also provide optimal and suboptimal solutions to antenna selection and dimension selection problems respectively, by slightly modifying the proposed algorithm for user selection. Numerical results and analysis are provided to evaluate the system capacity and to study the effect of the number of users and the receive antennas per user on the performance. Comparison among user selection, antenna selection and dimension selection is made.
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