| 摘要 |
A wireless communication system, for example UMTS, comprises at least one primary station (10) and a plurality of secondary stations (UE). The or each primary station has a transmitter for transmitting wireless signals on a downlink and each secondary station has a receiver (16) for receiving signals on the downlink and a transmitter signals on an uplink. In a normal, loaded condition a synchronisation channel (SCH) and a data channel (DPCH) are present on the downlink and closed power control is effected by measuring the ratio of signal to interference, hereinafter referred to as SIR, in a received downlink transmission, comparing the measured SIR with a target SIR and sending a power adjust indication (TPC) on the uplink to cause the primary station to adjust accordingly its transmitted power on the downlink. The secondary station monitors the downlink and, in response to detecting an unloaded cell condition, determines a target SIR offset and applies the target SIR offset to the target SIR to increase temporarily the target SIR to overcome interference due to the presence of the SCH on the downlink. |
