IFT 372 Wireless Communication - Helm - Quiz 8-9 + Lecture Activities

What is the chip rate for a direct sequence spread spectrum system that has 26 dB of processing gain and a data rate of 90 kbps? - Answer-Processing Gain = 10 log (Chip Rate / Data Rate) Given: Processing Gain = 26 dB; Data Rate = 90 kbps 10^(26/10) = Chip Rate / 90 kbps Chip Rate = 400 * 90 kbps = 36000 kbps = 30 Mbps What is the chip rate for a direct sequence spread spectrum system that has 23 dB of processing gain and a data rate of 50 kbps? - Answer-Processing Gain = 10 log (Chip Rate / Data Rate) Given: Processing Gain = 23 dB; Data Rate = 50 kbps 10^(23/10) = Chip Rate / 50 kbps Chip Rate = 200 * 50 kbps = 10000 kbps = 10 Mbps What is the chip rate for a direct sequence spread spectrum system that has 33dB of processing gain and a data rate of 75 kbps? - Answer-Processing gain = 10 log (Chip Rate / Data Rate) Given Info: Processing Gain = 33db; Data Rate = 75 kbps 10^(33/10) = Chip Rate / 75 kbps Chip Rate = 2000 * 75 kbps = 150 Mbps What is the maximum number of simultaneous calls a CDMA system with a processing gain of 29 dB, an Eb/No of 10 dB and intercell interference factor of 0.005 can support? - Answer-C(max) = SF / (Eb/N0) * 1 / (1 + β) Given: Gp = 29 dB = 800 (SF); Eb/N0 = 10 dB = 10; β = 0.005 C(max) = 800/10 * (1/1.005) = 80 * 0.995 = 790 calls What is the maximum number of simultaneous calls a CDMA system with a processing gain of 33 dB, an Eb/No of 10 dB and intercell interference factor of 0.015 can support? - Answer-C(max) = SF / (Eb/N0) * 1 / (1 + β) Given: Gp = 33 dB = 2000 (SF); Eb/N0 = 10 dB = 10; β = 0.015 C(max) = 2000/10 * (1/1.015) = 200 * 0.985 = 197 calls