Consider the design of adaptive equalizer for a cellular system operates in an urban area. If the carrier frequency is f=1800 MHz, symbol rate is 25 k symbols/sec and the mobile velocity v = 80 km/h, answer the following: (a) Determine f, the maximum Doppler shift. (b) Determine Te, the coherent time of the channel. [Hint: Te 9 16 2 [10 Marks] ] [10 Marks] (c) Find the maximum number of symbols that could be transmitted without updating the equalizer. [5 Marks]