(a) (b) What properties of maximal-length sequences make them well suited for spread spectrum systems? Why are Gold codes often used instead of maximal length sequences? Draw block diagrams of direct-sequence spread-spectrum transmitter and receiver. Briefly explain the operation of the delay-locked-loop. (c) A frequency-hopped spread-spectrum system uses 8-ary FSK (frequency-shift keying), with a data rate of 450 k bit s-, with a minimum hop between carriers of 15 kHz. (i) Determine the symbol rate. (ii) Assuming fast-hopping with four hops-per-symbol, determine the hop rate and chip rate. (iii) Using the hopping scheme in (ii), how many shift-register stages are required in a maximal-length-sequence generator to achieve a process gain of > 28 dB? (iv) What practical considerations might reduce the data rate in a real system?