GSM system applies both FDMA and TDMA scheme The bandwidth f

GSM system applies both FDMA and TDMA scheme. The bandwidth for GSM system is 25 MHz Suppose each channel require a bandwidth of 250 kHz and the each channel is divided into 10 time slot. How many concurrent user the system can support? What is the bandwidth used for each user? Suppose we now using the CDMA system The system wants to transmit bit sequence 0010 to user A and 1011 to user. Assume that we use the PN code of chip rate of 2. design 2 PN code for both A and B (assume that the PN code repeat at a frequency of 2) Encode a, b using PN code designed on (i) If we use PN_B to decode B, what is the output? (Assume that dot product is used on decode)

Solution

a) N= total channel= 25MHZ/250 kHz=100

1 channel have 10 time slots

Number of users= 100*10=1000

Bw= bandwidth of each user= 25 kHz