LTE: Will UE reads PSS and SSS signals once handover command received from from source eNB ?

Question

Once UE receives mobility control (contatins pci and dl BW etc) info in rrcconnectionreconfiguration message from source eNB, will UE reads PSS and SSS of target eNB ? bcz already have given pci .

Answer 1

As per my understanding, UE shall perform PSS and SSS at target cell otherwise how would it be able to latch on correct/intended cell. After reading PSS and SSS, UE knows the PCI of cell.

Comments

thanks Vimal Kumar Mishra  .

yes but in mobility control info contains PCI  ..

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Even I have mentioned in my answer, first UE shall do PSS and SSS then only it can find out the correct destination (target cell). At a particular time or location, UE may see # number of cells and but objective is to latch on correct destination (i.e. target PCI within the mobility control info).

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Yes i agree ...ok let me explain still more ... currently I am doing intra frequency handover ,once ue receives reconfiguration message contains mobility control info ,UE  started sync with target eNB (continues RACH is happening but not received target eNB) but from UE log i came to know that UE is not reading PSS and SSS signals . so i think UE is facing UL sync issue .... ie. current SFN  present in UE side is different and    target eNB current SFN is different. And one more thing observed from UE logs is CRC failure while PBCH decoding .
please suggest where i am going wrong..

UE log :

Answer 2

I think UE reads PSS and SSS not only to get the PCI value but also reads the PSS and SSS to get sync at radio frame, sub frame and symbol level to the target cell. After sync with target cell UE will be able to trigger the RACH procedure at the correct radio/sub frame/symbol. If RACH is successful then UE sends rrcreconfiguration complete message to the target cell to inform successful HO.

Answer 3

Hi Bheemappa,

DId you find the reason for your problem back then. I face a similar issue, could you please help?

Thanks

Comments

This is a very old thread, may be ask a fresh question and people may be able to help you.