Method and apparatus for adaptive channel direction information feedback in a heterogeneous system

A base station in a heterogeneous system, comprising:

• determining unit configured to determine, for a user equipment, total feedback bits for quantization of channel direction information, based on a trade off between accuracy of channel direction information quantization and reliability of uplink feedback transmission on a predetermined uplink feedback resource, wherein coordinated multi-point transmission between a local base station and a cross base station is performed for said user equipment in said heterogeneous system;
• and
• notifying unit configured to notify said user equipment of said total feedback bits for quantization of channel direction information that will be conveyed on said predetermined uplink feedback resource.

A method for channel direction information feedback in a heterogeneous system, comprising:

• receiving, at a user equipment, total feedback bits for quantization of channel direction information from a local base station, wherein said total feedback bits are determined based on a trade off between accuracy of channel direction information quantization and reliability of uplink feedback transmission on a predetermined uplink feedback resource, and wherein coordinated multi-point transmission between said local base station and a cross base station is performed for said user equipment in said heterogeneous system;
• and
• feeding back to said local base station quantized channel direction information in said total feedback bits on said predetermined uplink feedback resource.

A user equipment in a heterogeneous system, for which coordinated multi-point transmission between a local base station and a cross base station is performed, said user equipment comprising:

• receiving unit configured to receive a total feedback bits for quantization of channel direction information from the local base station, wherein said total feedback bits are determined based on a trade off between accuracy of channel direction information quantization and reliability of uplink feedback transmission on a predetermined uplink feedback resource;
• and
• feeding-back unit configured to feed back to said local base station quantized channel direction information in said total feedback bits on said predetermined uplink feedback resource.