Adaptive modulation and completion time in wireless broadcast channels

The purpose of this study is to analyze the effects of the adaptive modulation on completion time in wireless broadcast channels. The broadcast channels aim is to transmit data to more than one user at the same time. Addition to this hierarchical modulation transmits different data at the same time with different error protection levels; it is possible to use hierarchical modulation in wireless broadcast channels for transmission. In this thesis the new adaptive modulation methods, based on hierarchical modulation, were developed and their completion time performances were analyzed. Within this scope two new hierarchical modulation methods are suggested. Their results are compared with time division, opportunistic scheduling and adaptive modulation assisted methods. While the system cannot be attuned quickly to the changes in the channel states, it is seen that the new proposed methods decreases the completion time. However if the system is attuned the changes in the channel states quickly instead of the new methods, the one level transmission methods achieved better completion time.