Wireless transmission power control method and system

摘要

A wireless communication system includes a primary station which has a transmitter for transmitting wireless signals on a downlink, and a plurality of secondary stations each having a receiver for receiving signals on the downlink and a transmitter for transmitting on an uplink. In a normal, loaded condition a synchronization channel and a data channel are present on the downlink and closed power control is achieved by measuring the signal to interference ratio (SIR) in a received downlink transmission, comparing the measured SIR with a target SIR and sending a power adjust indication on the uplink to cause the primary station to adjust 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 which it applies to the target SIR to overcome interference from the presence of the synchronization channel on the downlink.

主权项

1. A method of power control in a wireless communication system comprising a primary station and a secondary station, the primary station configured for transmitting on a downlink and the secondary station configured for receiving signals on the downlink and transmitting signals on an uplink, wherein a synchronization channel and a data channel are present on the downlink and closed loop power control is effected by measuring a signal to interference ratio (SIR) in a received downlink transmission, comparing the measured SIR with a target SIR and sending a power adjust indication on the uplink to cause the primary station to adjust accordingly its transmitted power on the downlink, and wherein in an unloaded cell at least one common channel occupies an increased part of the received power in comparison to in a loaded cell, the method comprising in the secondary station:
monitoring the downlink for an unloaded cell condition by estimating if a cell is loaded or unloaded based on estimation of interference due to the at least one common channel; in response to detecting the unloaded cell condition, determining a target SIR offset; and applying the target SIR offset to the target SIR to increase the target SIR to overcome interference due to the presence of the synchronization channel during the unloaded cell condition on the downlink.