Uplink sounding reference signals configuration and transmission

Abstract

A method and apparatus for uplink sounding reference signals (SRS) transmissions are disclosed. A WTRU-specific configuration of WTRU-specific SRS subframes for performing SRS transmissions is received. A trigger is received in a subframe from a base station to transmit a first SRS. A first subframe is selected after the subframe in which the trigger is received which is both a WTRU-specific subframe and at least four subframes after the subframe in which the trigger is received. A determination if a maximum power is exceeded in a symbol in the selected first subframe is made. On a condition that the maximum power is not exceeded in the symbol in the selected first subframe, the first SRS is transmitted in the selected first subframe. On a condition that the maximum power is exceeded in the symbol in the selected first subframe and transmission of at least one channel type other than SRS-type at least partially overlaps in the symbol in the selected first subframe, the first SRS is dropped from the selected first subframe and the at least one channel type other than SRS-type is transmitted. On a condition that the maximum power is exceeded in the symbol in the selected first subframe and transmission of at least one other SRS at least partially overlaps in the symbol in the selected first subframe, transmission powers of the first SRS and the at least one other SRS are scaled equally to comply with the maximum power, and the first SRS is transmitted in the selected first subframe in accordance with the scaled transmission powers, and the at least one other SRS is transmitted in accordance with the scaled transmission powers.

Dependencies are inferred from the claim text.