Impact of imperfect link adaptation in EGPRS

In EGPRS, the link adaptation (LA) mechanism, i.e. matching the code rate to the prevailing radio channel condition, is the major element in maximising the throughput of a user and a system throughput as a whole. However, in a practical system perfect LA will not always be possible. This paper investigates-under a simulation environment-the downlink system level performance of EGPRS under perfect and imperfect LA. In addition, the conditions under which the EGPRS incremental redundancy (IR) mode of operation provides gain are highlighted. The scenario considered is a 1×3 macro-cellular interference limited environment; populated with mobiles with perfect receivers receiving e-mail and operating under TU50-NoFH radio condition