EET3802

.docx

School

ECPI University**We aren't endorsed by this school

Course

EET 380

Subject

Electrical Engineering

Date

Dec 18, 2024

Pages

Uploaded by dylanhoylenavy

1.How do you compare PCM with PWM and PPM?Pulse Code Modulation (PCM), Pulse Width Modulation (PWM), and Pulse Position Modulation (PPM) are three distinct signal modulation techniques used to encode information in various systems.**PCM** is a digital method that samples the amplitude of an analog signal at regular intervals and quantizes it into discrete values, which are then encoded into binary pulses. This technique is commonly used in digital audio systems such as telecommunications, CDs, and DVDs because it provides high fidelity and an accurate representation of the original signal. However, itrequires a higher bandwidth to transmit large amounts of data.**PWM** encodes information by varying the width of the pulses while keeping the frequency and amplitude constant. It is widely used in applications like motor control, light dimming, and power regulation because it offers efficient power delivery with smooth control. However, PWM can cause harmonic distortion if not properly filtered.**PPM** encodes information by altering the position of the pulse within a fixed time frame, with the position of the pulse indicating the value of the signal. This technique is commonly used in optical communications and remote-control systems because it is less sensitive to amplitude noise, making it more robust in noisy environments. However, it requires precise synchronization between the transmitter and receiver, which can be challenging in high-speed communication systems.Each of these techniques is suited to specific applications based on their accuracy, noise resistance, and efficiency requirements. PCM offers high accuracy but requires more bandwidth, PWM provides efficient power control,and PPM delivers robustness against noise but necessitates precise timing.2.A 8-bit ADC with 5v full scale voltage samples an analog signal at 1 kHz. Find the speed of the binary information at the output of the ADC.Speed of binary information = bit rate = Rb = bits/sample x sample/secRb = n X fN = number of bitsF = signal frequencySpeed of binary information = 8 * 1kHz = 8kHz

3.A linear PCM system uses an 8-bit ADC with 8v full scale voltage. Find the dynamic range and the SQNR in dB.Dynamic Range (DR) = 2^n-1 = 2^8-1 = 255DR(dB) = 20log(DR) = 48.13dBSQNR(dB) = 1.76 + 6n = 49.76dB4.In a T1 PCM-TDM system, 24 signals all with the same bandwidth of 4 kHz are multiplexed after sampling at their Nyquist rate. If an 8-bit ADCis employed in this T-carrier system, find the speed of the digital multiplexed line. Assume 8 Kbps overhead for the T-carrier.Nyquist rate = fs=2fm = 2*4kHz = 8kHzSpeed of digital multiplexed line = n*N*fs + overheadN = Number of signal n=number of bits8*24*8000 = 1.54Mbps5.For each of the following line codes, find the approximate required bandwidth of a T1 line.a.NRZ-L = 1.544MHzb.NRZ-M = 1.544MHzc.NRZ-S = 1.544MHzd.Unipolar-RZ = 0.772MHze.Bipolar-RZ = 1.544MHzf.AMI = 0.772MHz