Patent ID: 9071297
Filing Date: 2015-06-30
Classification: H04B,H04L,H04W

Abstract:
1. A method for codebook subsampling for enhanced four transmit antenna (4TX) codebooks in a Third-Generation Partnership (3GPP) Project Long Term Evolution (LTE) network performed by user equipment (UE), the method comprising: configuring a physical uplink control channel (PUCCH) for transmission of channel state information (CSI) feedback including a rank indicator (RI) and a precoding matrix (W1); jointly encoding the rank indicator (RI) and the precoding matrix (W1); and performing codebook subsampling for the enhanced 4TX codebook for at least one of: PUCCH report type 5 (RI/1st precoding matrix indicator (PMI)) in PUCCH 1-1 submode 1; PUCCH report type 2c (channel quality indicator (CQI)/1st PMI/2nd PMI) in PUCCH 1-1 submode 2; and PUCCH report type 1a (subband CQI/2nd PMI) in PUCCH 2-1, wherein the UE is configurable to perform codebook subsampling for the enhanced 4TX codebook for the PUCCH report type 5, the PUCCH report type 2c, and the PUCCH report type 1a and wherein for the PUCCH report type 5 (RI/1st PMI) in PUCCH 1-1 submode 1, when a maximum of four layers of data transmission is supported by the UE, the method includes, jointly encoding the RI and the W1 by employing codebook subsampling prior to configuring the CSI transmission at least for a rank indicator of two.