A new MAC design in LTE for MIMO multiuser schemes

Long Term Evolution (LTE) supports closed-loop Multiple Input Multiple Output (MIMO) techniques, as a mechanism to improve system performance. An open topic since the appearance of MIMO is whether the feedback load, that is required for its operation, compensates the performance improvement in practical systems. The availability of full Channel State Information at the Transmitter (CSIT) induces a large feedback load, so that any Partial CSIT scheme has a better chance to be considered in practical systems. This paper presents an LTE-MAC design for MIMO Multiuser transmission where Partial CSIT is required. The aim is to achieve simultaneous downlink transmissions to multiple users. Mathematical expressions are provided for the performance evaluation in terms of the system sum rate and throughput.