2.6 Post-Reading and Exercises

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2.

What conditions must be fulfilled in the transmission of information? Explain

with a simple example.

3.

How is information transmitted technically or generally? Explain with one ex-

ample each.

4.

What is the signal-to-noise ratio used for in technology, what forms of represent-

ation do you know? To which SNR does 3 dB, −3 dB, 10 dB, 120 dB correspond?

5.

Explain the terms data quantity, symbol and data transmission rate. What does

the maximum data transmission rate depend on for an information transmission?

What data transmission rates do you expect for common biosignals? Calculate the

maximum data transmission rate for a bandwidth of 5 kHz and a signal-noise-

ratio of 40 dB.

6.

What is meant by bandwidth, what is meant by a band-limited signal? State the

bandwidth of different bio-signals compared to technical signals.

7.

Give a definition for biosignals, including the generalised concept of information.

In your explanations, distinguish between evoked and autonomous biosignals

and give an example of each. What conclusions can be drawn from the newly ob-

tained definition?

Signals and Systems

1.

According to DIN 44300, how is the term signal defined?

2.

Name at least five reasons why one does signal processing.

3.

What is the difference between a continuous and a discrete-time signal? What is

a digital signal?

4.

Explain the relationship between signal and information by way of example.

5.

What is the relationship between signals and systems, on the one hand in signal-

processing systems from technology and on the other hand in signal-generating

systems from biology? Name the significance of each in the analysis of biosignals.

6.

Name four common biosignals of the heart. What diagnoses or conclusions can

be drawn from them?

7.

Explain the difference between univariate and multivariate signals, use the terms

un/dependent variable, give one example each.

Definition and Classification of Signals

1.

Explain the meaning and general use of the terms: expected value, mean, variance

and standard deviation. In each case, draw a distribution function that you would

expect to see for N subjects and M subjects when measuring height repeatedly.

Compare the expected values and standard deviations and justify the differences.

2.

Classify the term signal and give the appropriate definitions (a subclass is e.g.

deterministic signals).

3.

What is the characteristic of a periodic, or a transient signal?