Three users share a spread-spectrum transmission link. The system performance is to be evaluated while the users are sharing the link. The code sequences for the users are chosen from the family ofWalsh-Hadamard sequences of period N=64. The code sequences for the active users are:

{x} is sequence number 7
{y} is sequence number 11
{g} is sequence number 32

{x} = {0110 1001 0110 1001 0110 1001 0110 1001 0110 1001 0110 1001 0110 1001
0110 1001}

{y} = {0110 0110 1001 1001 0110 0110 1001 1001 0110 0110 1001 1001 0110 0110
1001 1001}

{g} = {0000 0000 0000 0000 0000 0000 0000 0000 1111 1111 1111 1111 1111 1111
1111 1111}

The signal power to channel thermal noise is 3 dB.

i. Find the probability of bit error assuming transmission is conducted on an asynchronous link.

ii. What would be the worst-case error probability of the asynchronous transmission ?

iii. Find the probability of error when users are transmitting on a synchronous link.