• State Resolved
  • Locked Locked
  • Replies 1 reply
  • Subscribers 98 subscribers
  • Views 1006 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

A question related to AIF2 CPRI LTE AxC mapping

ilke ALTIN
Intellectual 435 points


Hi,

I have a question regarding the mapping of the AxC samples in 20 MHz LTE configuration of CPRI protocol using AIF2.

From Chapter 3 of the AIF2 user guide I have read that for 20MHz LTE case for a 4x rate link has eight samples of antenna 0 (AxC0) followed by eight samples of AxC1. However I need to implement a different mapping for the AxC, where every sample of antenna 0 is followed by a sample of antenna 1. I have seen such a case in the document "AIF1-to-AIF2 Antenna Interface Migration Guide" in the Transmission Rule Setup Example of CPRI (page 21 of 36) which is said to use parameter X = 2. 

I would like someone to clarify two things for me, first of all; am I getting the correct idea from the figure in the document "AIF1-to-AIF2 Antenna Interface Migration Guide"? Is it really possible to change the mapping by changing only the X value, supposedly the DBMX value of linkconfig? If not how can I switch my CPRI LTE AxC mapping to the indicated configuration by changing the PE and PD parameters?

Thanks in advance,

ilke   

  • 0
    TI__Expert 4740 points

    Hi,

    Migration guide shows right idea about changing transmission and reception mapping.

    here is the code snippet you need to consider when you change the mapping.

       PdLinkSetup.PdCpriDualBitMap.DbmX = 1;// set X-1
      
       PdLinkSetup.CpriDmaCh[0]= 0; //match DbmX channel 0 to DB channel 0
       PdLinkSetup.bEnableCpriX[0]= TRUE; //enable CPRI X channel 0
      

       PeLinkSetup.PeCpriDualBitMap.DbmX = 1;//set X-1

       //PE Channel LUT setup and link routing selection (ChIndex number is matched with link number)
       PeCommonSetup.ChIndex3[0] = 0; //channel 0 for link 3
       PeCommonSetup.bEnableChIndex3[0] = TRUE;//Route egress channel 0 to dedicated CPRI link
       PeCommonSetup.CpriPktEn3[0] = FALSE; //use channel 0 for AxC

    like you see above, you also need to configure PE channel LUT and PD CPRI X lut setup except considering DBMX value. AIF2 fully support flexible mapping for any scenario.

    Hope this could help to you.

     Regards,

    Albert