| 摘要 |
<P>PROBLEM TO BE SOLVED: To reduce the peak power requirements of an uplink channel and to reduce a system interference level. <P>SOLUTION: A communication system has a downlink indicator channel (DL<SB>1</SB>) for the transmission of an indicator signal (302) indicating that a data packet (202) is scheduled to be transmitted on a downlink data channel (DL<SB>2</SB>) from a primary station to a secondary station. In operation, on detection of the indicator signal, the secondary station transmits a status signal, for example a negative acknowledgement signal (204), on an uplink channel (UL) to the primary station immediately before transmission of a positive acknowledgement (206) or negative acknowledgement signal to indicate a status of the received data packet. By providing the primary station with two chances to detect a case where the secondary station fails to detect the indicator signal, peak power requirements of the uplink channel can be reduced, thereby reducing the system interference levels. <P>COPYRIGHT: (C)2011,JPO&INPIT |
