Assume we have 3 devices that use CDMA channel access method. These devices have the following spreading sequences.
A=(1 1 1 1 1 1 1 -1)
B=(1 -1 -1 1 1 -1 -1 1)
C=(1 -1 1 -1 -1 1 -1 1)
Answer the following guestions: Which one of the devices will make data recovery impossible if they want to send data at the same time with other transmitters?