Dynamic downlink OFDM resource allocation for broadband multimedia services in wireless cellular systems

This paper presents an analysis of an efficient dynamic downlink multi-carrier resource allocation algorithm based on channel information suitable for packet-based voice and multimedia services in mobile cellular systems in a frequency-selective fading environment. The proposed algorithm sorts the time-varying sub-carrier responses according to their expected received signal strength, and allocates the best subcarrier(s) to each active user to satisfy its traffic requirements while maintaining the lowest possible transmitted power and smallest possible number of allocated sub-carriers. The performance of the proposed algorithm is evaluated in terms of user outage probability and throughput in relation to the system load. Analytical and simulation results are compared and used to examine the effects of using highly bandwidth-efficient adaptive modulation/coding schemes, performance degradation due to practical implementation, and shadowing on the system performance.