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Spread Spectrum Transmission Comparison

Introduction to Spread Spectrum Transmission

Guidelines

* What is it? Why is it important? What issues are addressed? How does it work?

Spread Spectrum techniques are methods by which a signal generated with a particular bandwidth is deliberately spread in the frequency domain, resulting in a signal with a wider bandwidth. Spread Spectrum establishes secure communication, increasing resistance to natural interference, noise and jamming, to prevent detection. It’s important in military applications when protecting communications.

Frequency Hopping Spread Spectrum (FHSS)

Guidelines

* What is it? How does it work? What issues are addressed? Why is it important?

Frequency hopping is one of two basic modulation techniques used in spread spectrum signal transmission. It is the repeated switching of frequencies during radio transmission, often to minimize the effectiveness of electronic warfare that is, the unauthorized interception or jamming of telecommunications.

Direct Sequence Spread Spectrum (DSSS)

Guidelines

* What is it? How does it work? What issues are addressed? Why is it important?

In telecommunications, direct-sequence spread spectrum (DSSS) is a modulation technique. As with other spread spectrum technologies, the transmitted signal takes up more bandwidth than the information signal that is being modulated.

Comparison between FHSS and DSSS

Technique | Advantages | Disadvantages |

FHSS | Cover large number of collocated-systems using directional antennas.Total parallel active systems located in similar geographic area are higher than the DSSS systems.Fixed broadband wireless access FHSS’s typical applications cover cellular deployments. | FHSS runs at a faster pace with minimum influence from environmental factors such as other radios stations, noise, reflections from other signals.FHSS is very robust-technology with little influence from reflections, other radio-stations or environment...