IEEE 802.11a and g use multiple modulation techniques in the same transmission bandwidth to provide different data rates. When the mobile terminal is close to the access point, a 64-QAM modulation is used, and as the modem goes to the coverage boundary of the access point, a BPSK modulation is used that requires substantially lower received signal strength to operate.
(a) If the data rate for the BPSK system is 12 Mb/s, what is the data rate of the 64-QAM modem?
(b) What is the difference between the received signal strength requirement of the 64-QAM and BPSK modulation techniques? Approximations used in Section 7.2 can be applied.
(c) If the coverage with 64-QAM is D meters, what is the coverage with a BPSK modem when we operate in a large indoor open area with a distance-power gradient of α = 2?
(d) Repeat part (b) for an indoor office area with a distance-power gradient of α = 3.