(a) Consider an audio signal comprised of the sinusoidal term s(t) = 3 cos 500nt (i) Find the signal to quantization noise ratio when this is quantized using 10-bit PCM (4 marks) (ii) How many bits of quantization are needed to achieve a signal to quantization noise (4 marks) ratio of at least 40 dB? (i) Amplitude shift keying (ASK) is to be used to transmit binary data with a given value of carrier amplitude, A, and noise power per hertz, No. Prove that a modulation index of m = 1 yields the minimum bit error rate. (6 marks) (ii) Binary information is transmitted at 10 kbps using on-off keying (OOK). The carrier frequency is 10 MHz, and the received carrier amplitude is 102 V. The additive noise power is 5 x 10-0 W/Hz. Design a coherent detector and find the bit error rate.