Patent ID: 8644231
Filing Date: 2014-02-04
Classification: H04B,H04L

Abstract:
1. A method of transmitting a feedback message through a feedback header, the method comprising: receiving a feedback request message comprising a feedback type field; and transmitting a feedback header as a response to the feedback request message, wherein the feedback header has a format comprising the feedback type field and a feedback contents field, wherein a value of the feedback type field indicates a type of information contained in the feedback contents field, and wherein when the value of feedback type field indicates a closed-loop (CL) multiple input multiple output (MIMO) feedback, the feedback contents field comprises a CL MIMO type field and MIMO information, the CL MIMO type field indicating any one of an antenna grouping, an antenna selection, a codebook based feedback and transition from CL MIMO to open-loop MIMO, and wherein when the CL MIMO type indicates the codebook based feedback, the MIMO information comprises N codebook indexes and N differential CQIs, wherein the N codebook indexes indicate codebooks used for N best subbands of M subbands according to channel quality indicator (CQI), where both M and N are natural numbers and M is larger than N, and each of the N differential CQIs indicates difference between a reference CQI and a CQI for each of the N best subbands.