Telefonaktiebolaget Lm Ericsson (publ)

M&aring;rten Ericson

Bo Engstr&ouml;m

Magnus K Almgren

Christoffer Andersson

A method and apparatus for controlling transmission power levels in a CDMA cellular communication system are disclosed, whereby a third (middle) control loop is interposed between an inner loop and an outer loop to form a cascaded power control loop. Certain quality indicators are coupled to the outer loop and middle loop. The outer loop produces a quality target value for the middle loop. The middle loop produces the SIR target value.

Power control in a CDMA mobile communication system

A transmission power control method and system are provided for use in a spread spectrum or CDMA mobile communications system, whereby an estimate of the achieved SIR is used as an additional parameter for the outer power control loop function. When the QoS and achieved SIR are both too low, the QoS is ignored and the SIR target value is instead controlled by the achieved SIR. Similarly, when both the QoS and achieved SIR are too high, the QoS is ignored and the SIR target value is instead controlled by the achieved SIR.

An efficient and effective power control in a mobile communications system is provided that adapts to rapidly changing radio transmission conditions in varying and often unpredictable situations. The value of a signal parameter detected from a signal received by a radio transceiver is compared with a desired signal parameter value, and a difference is determined. A transmit power control command is sent to the radio transceiver and may instruct, for example, an increase or decrease in the level of radio transmit power. Included with the transmit power control command is a power control indicator indicating whether a first or a second type of power control adjustment should be used by the radio transceiver depending upon the determined difference. In one example embodiment, the power control indicator is a single-flag bit. A first value indicates that the first type of power control adjustment should be used; the second value indicates that the second type of power control adjustment should be used. In any event, the power control indicator itself does not include specific details of the first or second type of power control adjustment. Because only the indicator is sent (and not the details), signaling overhead and bandwidth consumption related to frequently sent power control commands are kept to a minimum. The specific details of the first and second power control adjustments are initially stored in to the radio transceiver. Such details may be updated when desirable, but the frequency of such updating is likely to be infrequent. Alternatively, a power control indicator may be communicated using techniques other than adding one or more flag bits to a fast transmit power control message to effect a change in power control type as long as signaling overhead is not significantly increased.

Growing community of inventors

Luleå, Sweden

Mårten Ericson

Growing community of inventors

Luleå, Sweden

M&aring;rten Ericson

Mårten Ericson