Doc for understandig of XPIC Theroy

[Cost_Reducer]

Gent`s

anybody here who have a good document about theory of XPIC in wireless radio systems?
I have a costumer who have a 7,5 Ghz link with E******* "Marconi Long Haul" equipment in a 7+1 configuration. He had measured the XPD with 45 dB.
Ii it to much for a CCDP system with XPIC? He said also, that he ave many bit errors on the co channel....

Hope you can help me....


Thanks a lot

[Ryuuken]

What antenna do they use?
If they use Andrew antenna (and I think they do) visit


http://awapps.commscope.com/catalog/andrew/catalog.aspx?id=75

There you will find all Andrew antenna with detail specification. You will see that XPD for these antenna is usually about 30-38dB. So, 45 dB is a lot.
Now, maybe there are some other problems with link. I see it's n+1 configuration. Try with alignment of operating channels with protection channel. Sometimes if alignment is not done, can cause such bit errors. Normal values for alignment is around 30-40. Maybe 45. Any value beyond that indicates problem. Most probably with RPS module
When you do alignment there is a possibility to make a test. It has to be successful.

And one more thing. On both sides of hop, software release in Marconi LH has to be the same. For example, on both sides you have to have 2.5.3 build 23. Or whatever the release your customer have.
Latest release is 2.5.3 build 24. Ask E******* to deliver it to you or your customer. And apply it.

[byja]

Haven't got much experience with Marconi radios, but I do have with other radios in CCDP mode.
Try lowering the output power couple of dBs and see what happens. If possible, turn on the ATPC for all channels. What's your RSL anyway?

What did he actually measure for XPD? The antenna alone, or antennas plus XPIC?

[Ryuuken]

Lowering power can be helpful. Better solution is, as byja said, ATPC. Usually ATPC is set to RSL of -50dBm



Haven't got much experience with Marconi radios, but I do have with other radios in CCDP mode.
Try lowering the output power couple of dBs and see what happens. If possible, turn on the ATPC for all channels. What's your RSL anyway?

What did he actually measure for XPD? The antenna alone, or antennas plus XPIC?

[Cost_Reducer]

Hi Guys,

my problem with the XPIC and CCDP operation is fixed. I find out, there is a other carrier in one channel and he interfere my channel. I see it with a spectrum analyzer. I muted my TX on remote site and on local site there was a RSL of -63 dBm. Thats too much.
Thanks for your tips.

[byja]

Did you mute BOTH channels (horizontal and vertical) on far end? This RSL value looks a lot like received level on orthogonal ("contra") polarization.

[Cost_Reducer]

yes, i muted both TX. If i switch off the remote TX so i can see a interferer in my spectrum. I think it`s an other network operator here in the region. I must ask the frequencies authority who use the same/similar RF band... :confused: