Method and apparatus for feedback in multi-user multiple-input multiple-output (MU-MIMO) communication system
AssigneeSamsung Electronics Co., Ltd.
InventorsBruno Clerckx, Jun Il Choi, Ki Il Kim
Life of this patent
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Abstract
Provided is a feedback method and apparatus in a multiple-input multiple-output (MIMO) communication system. A terminal may determine a preferred pre-coding matrix for a neighboring terminal, based on a reference rank determined by a base station and a preferred pre-coding matrix of the terminal. The terminal may calculate a channel quality indicator (CQI) based on the preferred precoding matrix for the neighboring terminal, and may feed the CQI back to the base station.
Claims22
A communication method of a terminal in a multiple-input multiple-output (MIMO) communication system including a base station and the terminal, the method comprising:
- selecting a preferred first pre-coding matrix for the terminal based on a preferred rank of the terminal;
- extracting at least one preferred second pre-coding matrix for at least one neighboring terminal corresponding to the preferred first pre-coding matrix based on a reference rank and the preferred rank of the terminal;
- generating at least one channel quality indicator (CQI) of the terminal based on the preferred first pre-coding matrix and the at least one preferred second pre-coding matrix;
- and
- feeding the at least one CQI back to the base station.
A terminal in a multiple-input multiple-output (MIMO) communication system including a base station and the terminal, the terminal comprising:
- a first pre-coding matrix selecting unit configured to select a preferred first pre-coding matrix for the terminal, based on a preferred rank of the terminal;
- a second pre-coding matrix extracting unit configured to extract at least one preferred second pre-coding matrix for at least one neighboring terminal corresponding to the preferred first pre-coding matrix, based on a reference rank and the preferred rank of the terminal;
- a CQI generating unit configured to generate at least one channel quality indicator (CQI) of the terminal based on the preferred first pre-coding matrix and the at least one preferred second pre-coding matrix;
- and
- a transmitting unit configured to feed the at least one CQI back to the base station.
A terminal in a multiple-input multiple-output (MIMO) communication system, the terminal comprising:
- a receiver configured to receive a reference rank from a base station;
- a controller configured to determine a preferred rank of the terminal and to determine information to feed back to the base station based on the reference rank and the preferred rank of the terminal;
- and
- a transmitter configured to transmit the determined feedback information to the base station, wherein
- in response to the preferred rank of the terminal being greater than the reference rank, the controller determines to transmit feedback information comprising a rank indicator (RI) indicating a preferred rank that is restricted to being less than or equal to the reference rank, a pre-coding matrix indicator (PMI) indicating a preferred codeword selected by the terminal, and at least one channel quality indicator (CQI) of the terminal.
A terminal in a multiple-input multiple-output (MIMO) communication system, the terminal comprising:
- a receiver configured to receive a reference rank from a base station;
- a controller configured to determine a preferred rank of the terminal and to determine information to feed back to the base station based on the reference rank and the preferred rank of the terminal;
- and
- a transmitter configured to transmit the determined feedback information to the base station, wherein
- in response to the preferred rank of the terminal being less than the reference rank, the controller determines to transmit feedback information comprising a best companion channel quality indicator (CQI) comprising information that is associated with interference of at least one neighboring terminal.
A terminal in a multiple-input multiple-output (MIMO) communication system, the terminal comprising:
- a receiver configured to receive a reference rank from a base station;
- a controller configured to determine a preferred rank of the terminal and to determine information to feed back to the base station based on the reference rank and the preferred rank of the terminal;
- and
- a transmitter configured to transmit the determined feedback information to the base station, wherein
- in response to the preferred rank of the terminal being the same as the reference rank, the controller determines not to transmit feedback information to the base station.
Dependencies are inferred from the claim text.