Tutorial-1 (ECE 5^th Sem)         Subject: Digital Communication

Topic Covered: PCM, Sampling and SNR                                                      Date:05- 08-2016

Q.1. A television signal having a bandwidth of 4.2 MHz is transmitted using binary PCM system. Given that the number of quantization levels is 512. Determine:

a) Code word  length

b) Transmission bandwidth

c) Final bit rate

d) Output signal to quantization noise ratio.

Q.2. The bandwidth of an input signal to the PCM is restricted to 4  KHz input signal varies in amplitude form -3.8V to + 3.8V and has the average power of 30 mV. The required signal to noise  ratio is given as 20 dB. The PCM modulator produces binary output. Assuming uniform quantization.

a) Find the number of bits required per sample.

b) Output of 30 such PCM coders are time multiplexed. What would be the minimum required transmission bandwidth for this multiplexed signal?

Q.3.  The information in an analog signal voltage  waveform is to be transmitted over PCM system with an accuracy of +0.1%(full scale). The analog voltage waveform has a bandwidth of 100Hz and an amplitude range of -10 to +10 volts.

a) Find the minimum sampling rate required.

b) Find the number of bits in each PCM word.

c) Find minimum bit rate required in the PCM signal.

d) Find the minimum absolute channel bandwidth required for the transmission of the PCM signal.

Q.4. A PCM system uses a uniform quantizer followed by a 7-bit binary encoder. The bit rate of the system is equal to 50x10⁶ bits/sec.

a) What is the maximum message signal bandwidth for which the system operates satisfactorily?

b) Calculate the output signal to quantization noise ratio when a full load sinusoidal modulating wave of frequency 1 MHz is applied to the input.

Q.5. The information in analog waveform with maximum frequency f_m=3kHz is to be transmitted overran M-level PCM system where the number of quantization levels is M=16. The quantization distortion is specified not to exceed 1% of peak to peak analog signal.

a) What would be the maximum number of bits per sample that should be used in this PCM system?

b) What is the minimum sampling rate and what is the resulting bit transmission rate?

Q.6.  A signal having bandwidth equal to 3.5kHz is sampled, quantized and coded by a PCM system. The coded signal is then transmitted over a transmission channel of supporting a transmission rate of 50 k bits/sec. Determine the maximum signal to noise ratio that can be obtained by this system.

The input signal has peak to peak value of 4 volts and rms value of 0.2 V.

Q.7. A signal x(t) is uniformly distributed in the range + x_max . Evaluate maximum signal to noise ratio for this signal.

    Digital & Non Linear Control System (Assignment-1), UNIT-1 & 5

                             Last Date of Submission: 27-02-2016

Q1. Explain mathematical modeling of sample and hold circuit.

Q2. Write a short note on the following

1.                       Sample and zero hold
2.                            Frequency domain consideration in sampling and reconstruction
3.            Under sampling, Over sampling and Critical sampling
4.                   Nyquist rate and Nyquist interval

Q3. Discuss microprocessor based position and speed control system system along with block diagram and also discuss its algorithm.

Q4. Explain microprocessor  based temperature  control system along with its algorithm.

Q4. State and prove sampling theorem for low pass band limited signal.

8085 and 8086 Assignment

    Microprocessor  Assignment-1 for ECE 5th Sem

                                 *Last Date For Submission : 15 Aug,2013

1)     What is a microprocessor? Draw the table for evolution of Microprocessor? What are the basic functions of microprocessor? Differentiate between microprocessor & microcontroller? Describe the important applications of microprocessor.

2)     What are the essential components of a digital computer? Discuss the function of each component. Draw the block diagram of a computer showing its essential component

3)     What do you understand by single chip microcomputer? Where they are used? Give some example of micro controller.

4)     Draw and explain  the Functional Block Diagram of 8085 Microprocessor

5)     Illustrate the general bus organization of a microprocessor.

6)     Draw the pin-diagram of 8085 micro processor and give the name of signals associated with timing and control circuit and explain.

7)     What is bus? What are different types of buses supported by 8085? Explain Bus organization with diagram. How the processor sends and receives information from memory and I/O devices? Explain.

8)     Draw the register structure of 8085 and explain the function of each register? What is ALU and what is its function in 8085?

9)     Write the Instruction set of 8085 and explain the function of each instruction?

10)  Explain the function of the following Signals?

IO/ M,    INTR,     INTA, HOLD, HLDA AND READY

11)  What are addressing modes? Write different addressing modes in 8085

12)  Classify 8085 instructions in various groups. Give example of instruction for each group

13)  Discuss the role of timing and control unit of microprocessor?

14)  What are the Flags in 8085? Discuss?

15)  Discuss instruction cycle, machine cycle and T-state?

16)  Discuss fetch operation, decode and execute operation?

17)  What are One Byte, Two Byte and Three Byte Instructions? Give examples.

18)  Draw the block diagram of 8086 and explain the function of each block?

19)  Describe how 8086 fetches and executes an instruction with diagram?

20)  Draw and explain the timing diagram for fetch operation.

21)  Draw and explain the timing diagram for memory read operation.

22)  Describe the memory organization and I/O addressing capability of 8086 µP?

23)  Explain pipelining & parallel processing? What are its advantages?

24)  What is de-multiplexing? Explain the role and working of latches and Tran receivers? Why buffers are used? What is the role of ALE pin?

25)  Discuss the register organization of 8086? Explain the function of each register?

26)  Describe memory segmentation? What are its advantages?

27)  What are the flags in 8086? How many status flag does 8086 have? Discuss the role of each flags? What are conditional and control flag in 8086?

28)  What are Assembler Directives? Explain all the Assembler Directives of 8086?

29)  Explain the different types of Addressing modes in 8086 with example?

30)  Give the name of Program Control Instructions and explain each one?

31)  Write an 8085 Assembly Language Program for addition, subtraction, 1”s & 2”s Complement, Larger of 2 Nos. , Smaller of 2 Nos.

32)  Write down the Instruction Set of 8086 µP. Explain with suitable example Arithmetic & Logical instructions, Program Control Instructions, Jump & Conditional Jump, Subroutine Call, Loop & String Instructions.

33)  Answer the following to the point:

a)     In what way does Intel 8088 differ from 8086?

b)    What is the difference between logical address and physical address?

c)     Calculate the Physical memory Address in 8086 if DS=FFF2&FA=400E.

d)    How BIU of 8086 generates 20 bit address to access external memory?

e)     How many words do the queue stores in the 8086?

f)     What is the purpose of the instruction pointer?

g)    How registers of microprocessor are different than a RAM byte?

h)     What is the function of the 8086 DT/R and DEN signals?

i)      What is the difference between MOVAX, [1234] H &MOV AX 1234H?

j)      Explain how multiprogramming has become faster due to segmented memory.

k)     What is the word length of 8085 microprocessor?

l)      What is difference between ROM and RAM?

m)   What are nibble, bit and byte?

n)     What is the full form of VLSI?

o)    While executing a program, when the 8085 microprocessor completes the fetching of the machine code located at the memory address 2057H, what is the content of the program counter?

p)    The memory address of the last location of a 1K byte memory chip is given as FBFFH. Specify the starting address?

q)    How many memory locations can be addressed by a microprocessor with 14 address lines? 

r)      If the memories chip size is 2048×8 bits, how many chip are required to make up 16 K-byte memories.

s)     What is a tri-state device?

t)      What are the control signals necessary in the memory-mapped I/O?

u)     How many bytes make a word of 32 bits?

MATLAB Code for ploting Concentric Circles

In MATLAB  concentric circles can be plot by using transfer characteristics between Sine wave and Cosine wave. MATLAB program is here for plotting three concentric circle  
%%%%%%%%%%%% START %%%%%%%
clc;
clear all;
close all;
t=0:0.0001:10;
sin1=5*sin(2*pi*t);
cos1=5*cos(2*pi*t);
sin2=3*sin(2*pi*t);
cos2=3*cos(2*pi*t);
sin3=1*sin(2*pi*t);
cos3=1*cos(2*pi*t);
plot(sin1,cos1,'r',sin2,cos2,'b',sin3,cos3,'k');
legend('r= 5', 'r= 3', 'r= 1')
grid on;
axis equal;
%%%%%%%%%% END %%%%%%%%