Analog sensor data interference

I’m designing wireless sensor data network using Xbee in API mode.
MCU gets analog reading of Accelerometer then Xbee sends out to the host.
Analog sensor data gets extremely jittery(almost 1V) as soon as I power Xbee.
and It gets more jittery when I turn on other wireless sensor module.
could you help me solving this problem?

Thank you in advance,