About power controlol in WCDMA ?

[mckinson]

power control & wcdma & dynamic range

WCDMA ,what is difference between open loop and inner loop power control ?
And ,when use the open loop ? when use the inner loop ?
Best regards !

 

[eda4you]

WCDMA ,what is difference between open loop and inner loop power control ?
And ,when use the open loop ? when use the inner loop ?
Best regards !

Closed-loop power control is carried out at an 800 Hz control rate. The open loop sets Tx power level based on the Rx power received by the mobile and compensates for path loss and slow fading. The closed loop is for medium to fast fading and provides compensation for open-loop power control inaccuracies. The outer loop is implementationspecific and adjusts the closed-loop control threshold in the base station to maintain the desired frame error rate. The step size is adaptive, either 1 dB, 0.5 dB, or 0.25 dB. As with IMT2000DS, power control errors will directly subtract from the link budget.

The power control dynamic range is as follows:
 Open loop ±40 dB
 Closed loop ±24 dB
Power control errors are typically 1.3 dB (low mobility) or 2.7 dB (high mobility).
Dynamic range is similar to other existing networks:
Mobile 79 dB
Base station 52 dB
FDD isolation (45 MHz, 800 MHz, 80 MHz at 1900 MHz)
Class II mobile 55 dB Tx to Rx
Base 90 dB (higher effective power, 5 dB lower noise floor)

 

[vfone]

Open Loop Power Control:
-MS adjusts it’s initial transmitter power according to received signal level
-Typically up or down 1dB, approx 74dB range (24dBm to –50dBm)

Closed Loop Power Control:
-BTS commands MS to increase or decrease it’s transmission power at 1500 times per second (1500Hz).
-It is based on received signal to interference ratio (SIR) estimates in BTS and follows also the fast fading pattern at low and (lesser) medium speeds (< 50 km/h)

Outer Loop Power Control:
-Maintains link quality
-Optimizes capacity / range when the mobile is close to the edge of the cell
-The dynamic range of the Outer Loop is only ±6 dB

 

[mckinson]

Thank you , have any material about
WCDMA ?

Best regards !!

 

[eda4you]

Thank you , have any material about
WCDMA ?

Best regards !!

Many books have been uploaded in this forum. Use the search function and cdma or umts for search!