Method and apparatus for conveying precoding information in a mimo system

Abstract

Method and apparatus for conveying precoding information in a control message (M) from a first node ( 400 ) to a second node ( 402 ), with information on properties of an associated wireless data transmission (D) between the first and second nodes employing spatial multiplexing and precoding for the data transmission. The first node determines precoding parameters (P) for signal transmission to the receiving node, optionally based on feedback reports (F) from the receiving node. The first node encodes control information bits in precoding information fields of the control message by means of values in TBS fields of the control message, such that the TBS field values determine the interpretation of the bits in the precoding information field(s). The control message (M) is then sent to the second node.

1 . A method in a first node of conveying precoding information in a control message (M) to a second node, the control message containing information that describes properties of an associated wireless data transmission (D) between the first and second nodes employing spatial multiplexing and precoding for sending codewords corresponding to transport blocks in said wireless data transmission, comprising the steps of:
 determining precoding parameters (P) to be included in said control message to the second node,   encoding control information bits in at least one precoding information field of the control message (M) according to the determined precoding parameters (P) by means of values in payload size related TBS fields in the control message, wherein said TBS field values are set to determine the interpretation of said control information bits in the precoding information field(s), and   sending said control message with said precoding information and TBS fields to the second node.