CDMA - Advanced
This time, assume there are 3 senders whom interfere with eachother and
that the interfering transmitted bit signals are additive. The value received at a
receiver, however, is now the sum of the transmitted bits from all senders.
Assume that sender 1 has a CDMA code of (1, -1, 1, 1, -1, -1, 1), sender 2 has a CDMA code of (1, 1, -1, 1, -1, 1, -1), and sender 3 has a CDMA code of (1, 1, -1, -1, -1, -1, 1) and their combined output is: (-1, 1, -1, 1, 1, 3, -3)
Question List
1. Assuming you are receiver 1, what is the decoded bit? If it can't be done, answer with 'n/a'
2. Assuming you are receiver 2, what is the decoded bit? If it can't be done, answer with 'n/a'
3. Assuming you are receiver 3, what is the decoded bit? If it can't be done, answer with 'n/a'
Solution
1. Because the CDMA codes weren't well chosen, interference will render the receiver unable to decode the original bit
2. The decoded bit is: 1 for sender 2
3. The decoded bit is: -1 for sender 3
That's incorrect
That's correct
The answer was: n/a
The answer was: 1
The answer was: -1