Patent attributes
A wireless communication base station is disclosed. The base station includes a transceiver coupled to a controller configured to generate a sub-frame having first control region for a first set of users and a second control region for a second set of users that do not receive the first control region, the first control region has a fixed starting location within the sub-frame and the second control region has a starting location that is one of several possible starting locations within the sub-frame, wherein the controller is configured to cause the transceiver to transmit the sub-frame to the first and second sets of users without signaling the starting location of the second control region in the sub-frame.