Rate-Aware Adaptive Channel Allocation for Multi-User OFDM Systems

This paper addresses channel allocation for multi-user OFDM systems for real-time packet oriented data transmission. For high data rate wireless communication, optimum utilization of resources has become of utmost importance. The optimization problem we are facing is the minimization of the total transmitted power while meeting the Quality of Service and rate requirements in a multi-user OFDM transmission. The idea is to utilize the knowledge of rate requirements not only as a constraint, but also in the channel allocation process. We propose to include the rate requirements in a two-fold manner: i) to perform pre- calculation of the maximum number of channels per user and, ii) to define the set of users competing for the available channels. Thereby obtaining a much fairer allocation policy, that results in reduced total power at low implementation complexity.