Operating Manual Vol 1 - ES Documentation

SMIQDigital Standard 3GPP W-CDMA (FDD)Apart from this trivial case there are other cases in which problems may occur.The above example is modified by changing the channelization code of the second DPCH from 2 to 3:• a DPCH with 960 ksps, channelization code 1, 0 dB, data all 0• a DPCH with 480 ksps, channelization code 3, 0 dB, data all 1After despreading at symbol rate 480 ksps, the following power distribution is obtained:Fig. 2-160Incorrect detection at various symbol ratesThe 960-ksps channel (channelization code 1) is detected as channel 2 at 480 ksps. There is howeverno crosstalk to channel 3. Therefore the 480-ksps channel is detected with the original power and allbits can be restored.Despreading of the 960-ksps channel however gives the following power distribution:Fig. 2-161Non-restorable DPCH channelBoth channels synchronize with channel 1, despreading is no longer possible with these level conditions.For despreading all transmitted DPCHs, two channels of half the symbol rate (channelization codes 2n,2n+1) should therefore be avoided for each channel used with a certain symbol rate (channelizationcode n). This is continued for four channels of one fourth of the symbol rate (channelization codes 4n,4n+1, 4n+2, 4n+3), etc.For further information refer to section 2.14.2.9.1125.5555.03 2.233E-9