Modified SIR values for fast power control

A receiver comprising a fast power control unit, said fast power control unit being arranged to continuously control a quality measure of a radio channel, wherein the quality measure is a modified Signal to Interference plus noise ratio (SIR) in which an influence from self interference has been removed, wherein

• the fast power control unit comprises a first processing unit comprising a model of the radio channel determined at least based on known, demodulated pilots, said model comprising a self interference impairment term RISI scaled by a first fitting parameter A and a noise impairment term Rn scaled by a second fitting parameter B,
• the first processing unit is arranged to adapt values of the first and second fitting parameters A, B to fit the model to measured received pilots,
• the first processing unit is arranged to determine that the radio channel has a high Carrier to Interference ratio and is a dispersive channel, thus requiring determination of the modified SIR;
• the first processing unit is arranged to determine the modified SIR as a relation between a signal power, the second fitting parameter B and the noise impairment term Rn without employing the self interference impairment term RISI;
• the processing unit is arranged to determine when the first fitting parameter A decreases below a preset value, and thereupon set the first fitting parameter A to zero, re-estimate the value of the second fitting parameter B, and use the re-estimated second fitting parameter B in determining the modified SIR;
• wherein the receiver further comprises a second processing unit arranged to calculate the self interference comprising:
• a power estimation unit arranged to:
• estimate a signal power and a noise power of the pilots or a code in which the pilots are incorporated from each RAKE finger output, and to
• estimate the total signal power over all codes for each finger output using the signal power on the pilots or the code in which the pilots are incorporated and known power settings of the transmitted codes, and
• a self interference estimating unit arranged to estimate the self interference for each finger output as the contribution of the total signal power over all codes and all finger outputs except the finger output for which the self interference is estimated.

A method for continuously controlling a quality measure of a radio channel, comprising continuously determining a modified Signal to Interference plus noise ratio (SIR) in which an influence from self interference has been removed, the continuous determination of the modified SIR comprising the steps of

• determining a self interference impairment term RISI scaled by a first fitting parameter A,
• determining a noise impairment term Rn scaled by a second fitting parameter B,
• adapting the first and second fitting parameters A, B to fit a model of the radio channel to measured received pilots,
• determining that the radio channel has a high Carrier to Interference ratio and is a dispersive channel, thus requiring determination of the modified SIR;
• determining the modified SIR as a relation between a signal power, the second fitting parameter B and the noise impairment term Rn without employing the self interference impairment term RISI;
• determining when the first fitting parameter A decreases below a preset value, and thereupon setting the first fitting parameter A to zero, re-estimating the second fitting parameter B, and using the re-estimated second fitting parameter B in determining the modified SIR;
• using a RAKE receiver to feed known pilots from respective finger outputs of the RAKE receiver to a fast power control unit;
• wherein the RAKE receiver comprises at least one finger output for each significant fading path in the radio channel;
• and
• wherein the number of finger outputs of the RAKE receiver fed to the fast power control unit is larger than the number of finger outputs fed to a RAKE combiner for data processing.

A method for continuously controlling a quality measure of a radio channel, comprising continuously determining a modified Signal to Interference plus noise ratio (SIR) in which an influence from self interference has been removed, the continuous determination of the modified SIR comprising:

• determining a self interference impairment term RISI scaled by a first fitting parameter A,
• determining a noise impairment term Rn scaled by a second fitting parameter B,
• adapting the first and second fitting parameters A, B to fit a model of the radio channel to measured received pilots,
• determining that the radio channel has a high Carrier to Interference ratio and is a dispersive channel, thus requiring determination of the modified SIR;
• determining the modified SIR as a relation between a signal power, the second fitting parameter B and the noise impairment term Rn without employing the self interference impairment term RISI;
• determining when the first fitting parameter A decreases below a preset value, and thereupon setting the first fitting parameter A to zero, re-estimating the second fitting parameter B, and using the re-estimated second fitting parameter B in determining the modified SIR;
• estimating a signal power and estimating a noise power of pilots or a code in which the pilots are incorporated from each finger output of the RAKE receiver,
• estimating the total signal power over all codes for each finger output using the signal power on the pilots or the code in which the pilots are incorporated and known or blind detected power settings of the transmitted codes, and
• estimating the self interference for each finger output as the contribution of the total signal power over all codes and all finger outputs except the finger output for which the self interference is estimated.