8.9 consider the design of an ofdm modulated signal. assume that the transmitter operates at a 10 mhz complex sample rate, and that the maximum expected delay spread is less than 1 s. (a) what is the complex nyquist sample period, ts (which is not the length of the ofdm symbol)? (b) to assure orthogonality, what is the minimum number of samples to use for the cyclic pre x? ((c) if the ofdm symbol has 100 subcarriers, what is the subcarrier spacing in frequency? (d) if the ofdm symbol has 100 subcarriers, how long in time is the ofdm symbol including the cyclic pre x determined previously?