Frequency-Domain Link Adaptation for Wideband OFDMA Systems

A novel frequency-domain mutual-information- based adaptive coding and modulation (MI-ACM) link adaptation technique has been developed in the European research project WINNER. On the link level, it has proven to provide near- optimum performance. On the system level, however, next to link adaptation also other system functions make opportunistic use of frequency selectivity and, hence, they potentially affect the achievable gains of MI-ACM. This contribution investigates the gains of MI-ACM compared to standard approaches using dynamic system-level simulations in the downlink of an urban macrocellular deployment. It is found that depending on the system load, scheduling policy, and the spatial processing scheme, up to 90% gains over standard approaches in terms of spectral efficiency are achievable.