Allocating control channel elements to downlink control channels

摘要

A method and apparatus is provided for allocating shared control channel resources. The control channel elements (CCEs) are allocated in units referred to as CCE sets. Each CCE set includes one or more control channel elements. Early commitment of control channel elements in a CCE set to a specific scheduling entity is avoided in situations where two or more candidate sets are available for the scheduling entity. In this case, the CCEs belonging to the candidate sets are designated as an alternate resource for a first scheduling entity. A CCE designated as an alternate may be allocated to another scheduling entity as long as such allocation does not block the first scheduling entity.

主权项

1. A method of allocating control channel resources at a transmitter, the control channel resources being allocated to a plurality of scheduling entities, said method comprising:
determining shared control channel elements allocated to the downlink control channels for the scheduling entities, wherein each control channel element has an allocation state of used, unused, or alternate; determining an availability state of one or more candidate sets for a first scheduling entity based on the allocation states of the control channel elements within each candidate set, wherein each set comprises a subset of said control channel elements for the downlink control channels; if two or more candidate sets are available, tentatively allocating the control channel elements in the two or more available candidate sets to the first scheduling entity by changing the allocation states of the corresponding control channel elements in the available candidate sets to alternate; and if only a single candidate set is available, finally allocating the control channel elements within the available candidate set to the first scheduling entity by changing the allocation state of the control elements within the single available candidate set to used; and transmitting from the transmitter the allocated control channel elements over the downlink control channels.