Introduction

Question 1

what is a dicrete time signal? Draw one

Answer 1

Discrete signal is a signal with a fixed sampling rate that captures data as a discrete set of values

Question 2

what is a sampling instant?

Answer 2

It is the rate at which the sampling happens - shammons theory states that it should be at least twice the highest frequency is the sample

Question 3

two catagories of discrete time signals…

Answer 3

sampled data signals and digital signals

Question 4

desribe a sampled data signall

Answer 4

displays a continous set of amplitude values

Question 5

describe the characteristics of a digital signal

Answer 5

discrete and quantized set of amplitude values =- where the quantization error is eqaul to += half N where n = 2^N - the amount of bits basically

Question 6

What does n denote

Answer 6

either the amount of samples (could be in a period or a cycle or just in total) or in terms of quantization the amount of bits available to represent the amplitude of an analogue signal

Question 7

Discribe a typical analogue input to output DSP Scheme

Answer 7

Analogue input ->ADC -> DSP -> DAC -> Analogue output

Question 8

Why is it important to have the right number of samples?

Answer 8

The output signal may be reduced in amplitude

Question 9

Describe what a “sweep through” is and how it relates to freqencies and samples per a second

Answer 9

A sweep through goes through all of the frequencies in order to test different filters (low bandpass and high). The output (y[n]) will display amplitude peaks

Question 10

What may changing the “multiplier coeffiences” do? Why would you do that?

Answer 10

more or less pronounced band pass effect

Question 11

Describe and state the formula used to calculate the sampling frequency of a sample

Answer 11

called shammons formula and states the minum required sampling frequency to capture all the data of an analog signal call be calculated as 2f1 where f1 is equal to the highest frequency

Question 12

What is the technical name for the maximum frequency

Answer 12

Nyquist frequency (f1)

Question 13

What is the technical name for the minum sampling rate the capture the data?

Answer 13

folding frequency (2f1)

Question 14

LTI is strictly….

Answer 14

It is a digital approach - avoiding any analogue circuity or techniques

Question 15

describe unit step

Answer 15

This is where lots of unit impulses are held [u[n]

Question 16

describe impulse

Answer 16

sigma [n] is where it is a spit of 1 discrete signal

Question 17

describe ramp

Answer 17

r [n] where the signal ramps up

Question 18

describe exponetial

Answer 18

exponetial can either be decaying (b <0) flat b = 0) or risingwhere b > 0) can be imaginary and real to represent sin and cosine

Question 19

describe sin and cosine

Answer 19

where a component of the signal represents a sin and cos sine part

Question 20

describe why simple functions are important in DSP

Answer 20

because they are easy to represent and can be combined together to produce complex signals

Question 21

Name the main DSP module processor

Answer 21

LTI - linear time invarient

Question 22

NAme the different operations tat an LTI processor can perform

Answer 22

Memory Addition/subtractions multiplication/division multiple numbers by there constants (multiplier coeffiences

Question 23

Name the way of representing signal functions graphicalyl

Answer 23

Block diagrams

Question 24

Give one basiic definition of a recursive function

Answer 24

it has a feedback loop

Question 25

Draw block diagram

Answer 25

Question 26

What is the formula of this?

Answer 26

Question 27

block diagram of….

Answer 27

Question 28

Properties of recurisive formulas for LTI processor

Answer 28

linearity

causality

invertiblility

time invarience

stability

memory