a. Consider a multipath channel with a delay spread of 5 µs through which it is desired to transmit data at 500 kbps. Design an MCM system that has a symbol period at least a factor of 10 greater than the delay spread if the modulation to be used on each subcarrier is QPSK.
b. If an inverse FFT is to be used to implement this as an OFDM system, what size inverse FFT is necessary assuming that the FFT size is to be an integer power of 2?