If Tx cable is swapped with Rx antenna cable and Rx cable is swapped with Tx antenna cable so you will get poor Rx level in that sector.
If antenna cables of two different sectors are swapped then you will get wrong BCCH or PN on that sector which u shud get.
Ex:- If alpha cable is swapped with beta port or beta cable is swapped with alpha port then you will get alpha PN in beta direction and beta PN in alpha direction.
usally we have 3 sector site(sector-1(alpha),Sector-2(Beta) and Sector-3(Gamma)
Through drive test tool u can find out the cross feeder or sector swap.