Ntt Docomo, Inc.

Ozgun Bursalioglu

Satoshi Nagata

Lan Chen

Yuichi Kakishima

Anass Benjebbour

Haralabos Papadopoulos

Yu Jiang

Xiang Yun

Carl-Erik W Sundberg

Techniques for providing codebooks extended by gain information that can be transmitted in a reduced amount of signaling are disclosed. A user equipment includes a transmission and reception unit communicating a radio signal with a base station in accordance with MIMO (Multiple Input Multiple Output) transmission and a codebook storage unit stores predefined codebooks to specify precoding matrices for use in the MIMO transmission. The codebooks are arranged to represent phase information and gain information and a channel measurement unit measures channel conditions based on reference signals transmitted from multiple antennas in the base station. A codebook selection unit selects a codebook to be indicated to the base station from the stored codebooks based on the measured channel conditions and instructs the transmission and reception unit to indicate feedback information to the base station and the feedback information includes a codebook index for identifying the selected codebook.

User equipment and base station

A method and apparatus for tree position adaptive SOMA receiver structures are disclosed herein. In one embodiment, a device for use in a wireless communication system comprises a receiver to receive information-bearing signals from the transmitter wirelessly transmitted using OFDM and bit interleaved coded modulation, where the receiver includes an inner decoder structure having a soft output M-algorithm (SOMA) based multiple-in multiple-out (MIMO) joint demapper that uses a SOMA-based MIMO detection process to perform joint inner demapping over each tone, and wherein the SOMA-based MIMO joint demapper is operable to search a detection tree for each tone using a tree-search symbol order that is adapted for each tone based on channel state information and extrinsic information from the outer decoder, where only a number of best alternatives from every level of the tree are expanded.

Tree position adaptive soft output M-algorithm receiver structures

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Palo Alto, CA, United States of America

Ozgun Bursalioglu