Course : comunication systems Problem 3 [20 Points] Consider a direct sequence s
ID: 2292787 • Letter: C
Question
Course : comunication systems
Problem 3 [20 Points] Consider a direct sequence spread spectrum system. The source outputs the information sequence"00101"at a rate of 1000bit/sec. The spreader has a chip rate of 4000bit/sec and uses the spreading code "1010 1001 0100 1010 1011" Determine the transmitted bit sequence (i.e, the output of the spreader) and the transmission speed. Show that if the transmitted sequence is despresd at the receiver using the same speading code, the output is "00101" a. b.Explanation / Answer
a) Line speed is simply the data rate at which serialpCM bits are clocked out of PCM encoder out to transmission line. Line speed is dependent on sample rate and number of bits in the compressed PCM code.
Line speed= Samples/ Second * Bits/ Sample= 1000bits/sample*5 samples/ second= 5000bits/ second
b)Transmitted sequence is despresd at the receiver using the same spreading code, the output is "00101"
20 samples/second*4000 bits/ samples= 80000bits/ second