co-channel rejection

I have co-channel and adjacent channel rejection problem in my WiMAX products with zero IF, build-in LNA in tranceiver and digital IQ.
The receiving BER will be un-acceptable when co-channel and adjacent channel interference become higher.
Can anyone have any idea about the problem?

Hello,

Is your reference sensitivity ok?
What about the BER performances for high input power levels?

RFCMOS.

Sensitivity w/o interference is OK.
BER performances for high input power levels is OK.

Thanks
Cren Yen

Hello,

Usually, co-channel performances are mainly determined by the equalizer performances. Just to be sure about you set-up. Do you perform the measurements at system level? By system, I mean are you using a baseband...?