According to the teachings herein, an LTE or other wireless communication network provides for independent control of SRS transmissions by a UE or other wireless device. The network advantageously sends DCI messages for SRS power control using a modified format 3/3A, where the message length conforms to that used for conventional format 3/3A messages but where the message is masked using a distinct RNTI. Correspondingly, the wireless device is configured to recognize from the distinct RNTI that the received TPC commands are targeted to controlling the uplink transmit power used by the wireless device for SRS transmissions.