tDPCH (W-CDMA(3GPP)/HSPA)
Automatic (See W-CDMA(3GPP) Standard Setups/Presets Table.)
: 0 to 149 (x256 chips)
Selects automatic or manual control of the setting.
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is determined automatically as a result of measurement for the specified . |
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Manually set the tDPCH-offset value directly in integer units of 256 chips/unit. |
indicates the time offset (x256 chips) from the CPICH Common Pilot Channel slot 0 start position to the DPCH Dedicated Physical Channel slot 0 start position. Correct specification of the chip offset value and identifying the correct slot boundary for the demod bits is important to obtain good results for symbol measurements such as EVM Error vector magnitude (EVM): A quality metric in digital communication systems. See the EVM metric in the Error Summary Table topic in each demodulator for more information on how EVM is calculated for that modulation format., magnitude, and phase errors.
In the 3GPP standard, compressed mode signals have several power-off slots during the transmission. This power-off period prevents active channel identification in code domain. Without identification as active channels, (timing offset of DPCH from CPICH) cannot be detected. This means that the slot boundary for a code channel is not correctly identified, which in turn means the demodulation bits and code channel power are affected. Setting manually helps to correctly examine compressed mode signals because of the adjusted slot boundary.
See Also
