

PN code = 0011011 
B: 1011011 
then node B will decode as follows:
received: 1011011 PN code: 0011011 XOR  1000000 NOT  0111111 Majority = 1 ===> 1 
(You can compare the received data with the PN code using an Exclusive OR operation)


PN code = 0011011 
(Low amplitude = 0, and high amplitude = 1)



Namely:

Let's consider for each case whether the receivers B and D can decode the transmission correctly....

What the receivers B and D will decode:
Result:


What the receivers B and D will decode:
Result:




∞ 1 / R_{corr}(τ) =   p_{i}(t) p_{j}(t+τ) dt (See: click here) T / 0 
The function p_{i}(t) and p_{j}(t) are the wave forms of the two PN codes.
(Don't worry, you don't need to know the details of correlation  it's there for completeness sake....)

Intermediate values (between 0 and 1) indicate how much the codes have in common.
