GitHub - venkateshsathya_RML22_ Dataset generation code for modulation classification

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We want to design a digital circuit that converts Gray code (ABC) to Binary code (xyz). Set up a 8-to- 1 line multiplexer so that the output gives y as a function of ABC. "A" is given to the most significant bit of the control inputs of the multiplexer. "C" is given to the least significant bit of the control inputs of the multiplexer.

Pulse-code modulation (PCM) is the standard form of digital audio in computers, compact discs, digital telephony and other digital audio applications. Figure 3 shows the 3bit PCM system that transmit the 250 kHz analog signal with the voltage range from -6 mV to 6 mV. i) Identify the quantized value, voltage range and binary code for each level by building your own quantization table. ii) Calculate the minimum sampling rate and sampling time. ii) Identify the corresponding sampled voltage, the quantized voltage and binary code if the input signal is sampled at time t1 = 2us, t2 = 4us, t3 = 6us, t4 = 8µs. iv) Sketch the output in (iii) if it is fed to Manchester coding line encoder with bit rate of 20000 bit/sec and amplitude of +4 V. 5 4 3 2 10 Timel(usec) Figure 3 Amplitude (mV)

3. Some GPS receivers use 1 bit ADCS (Analog-to-digital Converters) to sample and quantize the signal i.e. the output of the ADC is simply 2 quantization levels: -1 or +1. This is typically done to save on power. (a) What is the quantization SNR? How does it compare to typical thermal noise SNR of a GPS signal before correlating with the CDMA code? (b) Justify, how come it is possible to sample the signal using a single bit and still get good performance.