(a) Give the block diagrams for CDMA Direct Sequence Spread Spectrum (DSSS) transmitter and receiver and briefly explain the operation of each. [4 Marks] (b) The cellular concept relies on two important features 'frequency reuse' and 'cell splitting,' describe each of these features. [4 Marks] (c) Explain the major elements of an Orthogonal Frequency Division Multiplexing (OFDM) System (Transmitter and Receiver); use a block diagram to aid the explanation. [8 Marks] (d) Briefly define each of the following three wireless protocol technologies: (1) Narrowband Internet of Things (NB-IoT), (ii) LoRa (Long Range) is a low-power wide- area network (LPWAN), and (iii) SigFox. [9 Marks]