Question

# (a) The waveform of a pulse wave is illustrated below. The pulse duration T = 1ms and the period T = 4 ms. What is the fundamental angular frequency? Show the expression of the n-th harmonic frequency component of the pulse wave. Sketch the spectral distribution of the pulse wave and label the frequency of zero crossing. (b) A digital coded transmission system uses a cyclic code generator of x³ + x² +x5 + x³ + x + 1 for error detection. The digital data to be encoded is 10001011 1001, which is 12-bit temperature data provided by an analogue to digital(ADC) converter. Using the generator determine the transmitted cyclic code. (c) Illustrate in the time-domain the PSK and FSK waveforms in Figure QB2, where the first two bits in Non-return-to-zero (NRZ) have been sketched. Assume the baseband data is 01011010 at a bit rate of 16kbps and is modulated with the carrier. (1) Let the mark (HIGH) and space (LOW) frequencies used by an FSK modulator beset to 64kHz and 32kHz, respectively. Sketch the resulting FSK waveform representing the bit stream in Figure QB1.15 (II) If the carrier frequency is 16kHz, sketch the PSK waveform representing the bitstream in Figure QB1.(5 Marks)  Fig: 1  Fig: 2  Fig: 3  Fig: 4  Fig: 5  Fig: 6  Fig: 7  Fig: 8