5. A communication system uses OFDM modulation with the following parameters: 127 subcarriers, modulation formats of 16QAM, 32QAM or 64QAM, and symbol duration of 0.5s. Determine: The symbol rate. [1] The maximum and minimum gross system bit rates. [6] The gross bit rate if the subcarriers are modulated as follows: 70 subcarriers at 16QAM, 32 subcarriers at 32QAM and 25 subcarriers at 64QAM. [3]