Transmit Power Control Time Delay Compensation in a Wireless Communications System
2002 (English)Patent (Other (popular science, discussion, etc.))
The present invention compensates for transmit power control time delays between a radio transmitter and receiver that adversely affect the transmit power control process. A time delay associated with a power control loop is compensated for by adjusting a detected signal quality value of a received signal, e.g., signal-to-interference ratio (SIR), based on one or more previous power control commands already sent but whose effect has not yet been experienced. Because the determined signal quality value of the received signal is adjusted based on one or more power control commands already sent but yet to take effect, the transmit power level control command is appropriately determined so that it also takes into account a power control loop time delay. The delay compensation value may be determined based on the output power of a single, previously generated transmit power control command, or on plural previously generated transmit power control commands, depending upon the length of the time delay. If the adjusted signal quality parameter exceeds the target signal quality parametery the generated power control command directs a decrease in transmit power, and the compensation factor causes a decrease in the subsequently determined signal quality parameter. If the adjusted signal quality parameter is less than the target signal quality parameter, the generated power control command directs an increase in transmit power, and the compensation factor causes an increase in the subsequently determined signal quality parameter.
Place, publisher, year, edition, pages
IdentifiersURN: urn:nbn:se:liu:diva-98187OAI: oai:DiVA.org:liu-98187DiVA: diva2:652460
Ericsson Telefon AB L M US6493541 (2002-12-10)