Method and apparatus for channel resource mapping in carrier aggregation
Methods and apparatus for preventing physical hybrid automatic repeat request (HARQ) indicator channel (PHICH) ambiguities or collisions, for example, in a multi-carrier system or when transmitting multiple streams over multiple antennas, are described. Methods may include dividing resources or groups among multiple component carriers (CCs), using and assigning unused or vacant resources to CCs, forcing usage of adaptive HARQ processes in specified scenarios, setting a value for the cyclic shift of the corresponding uplink demodulation reference signals (DMRS) to a previous value for semi-persistent scheduling, and assigning a different first resource block for semi-persistent scheduling uplink resources and random access response grants for multiple CCs.
1. A method implemented at a base station for avoiding feedback channel resource collision, comprising:
determining a feedback channel resource collision; and
forcing an adaptive feedback channel process for each uplink component carrier having a feedback channel resource collision.
2. The method of claim 1 , wherein feedback channel resource collision determination checks sameness of lowest resources allocated among an uplink component carriers.
3. The method of claim 1 , wherein a non-adaptive feedback channel process is used for one uplink component carrier having a feedback channel resource collision.
4. A base station configured to avoid feedback channel resource collision, comprising:
a processor configured to determine a feedback channel resource collision; and
the base station configured to force an adaptive feedback channel process for each uplink component carrier having a feedback channel resource collision.
5. The base station of claim 4 , wherein feedback channel resource collision determination checks sameness of lowest resources allocated among an uplink component carriers.
6. The base station of claim 4 , wherein a non-adaptive feedback channel process is used for one uplink component carrier having a feedback channel resource collision.