New deployments are needed to address the

future needs of 4G networks like high data rate

support for clustered users. As a result, there is

a shift in paradigm for MIMO increasing

the number of antennas at a single cell site to

distributing multiple antennas over a cell area.

Furthermore, such distributed antennas may be

in different power levels, and also in different

antenna configurations. These add an interesting

aspect and require scalable designs as well as

interference management as part of MIMO

improvements. Geographically separated antennas

implemented as remote radio heads can be

controlled by a centrally located baseband unit

using high-speed standardized fiber interfaces.

Such low-latency fiber interfaces ensure good

synchronization across antennas and make the

transmission distributed antennas as a natural

extension of MIMO.-New deployments are needed to address the

future needs of 4G networks like high data rate

support for clustered users. As a result, there is

a shift in paradigm for MIMO　increasing

the number of antennas at a single cell site to

distributing multiple antennas over a cell area.

Furthermore, such distributed antennas may be

in different power levels, and also in different

antenna configurations. These add an interesting

aspect and require scalable designs as well as

interference management as part of MIMO

improvements. Geographically separated antennas

implemented as remote radio heads can be

controlled by a centrally located baseband unit

using high-speed standardized fiber interfaces.

Such low-latency fiber interfaces ensure good

synchronization across antennas and make the

transmission　distributed antennas as a natural

extension of MIMO.