Week 1 iLab Report
NETW360: Wireless Technologies and Services
OPNET Preparation and Spread Spectrum Transmission Comparison
Professor: Murad Dikeidek
Spread Spectrum Transmission Comparison
Spread Spectrum Transmission
In telecommunication and radio communication, spread-spectrum techniques are methods by which a signal with a particular bandwidth is deliberately spread in the frequency domain, resulting in a signal with a wider bandwidth. These techniques are used for a variety of reasons, including the establishment of secure communications, increasing resistance to natural interference, noise and jamming, to prevent detection, and to limit power flux density for example in satellite downlinks.
- Resists intentional and non-intentional interference
- Has the ability to eliminate or alleviate the effect of multipath interference
- Can share the same frequency band (overlay) with other users
- Privacy due to the pseudo random code sequence (code division multiplexing)
- Bandwidth inefficient
- Implementation is somewhat more complex.
Frequency Hopping Spread Spectrum (FHSS)
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. It also is known as frequency- hopping code division multiple access (FH-CDMA). Spread spectrum enables a signal to be transmitted across a frequency band that is much wider than the minimum bandwidth required by the information signal. The transmitter "spreads" the energy, originally concentrated in narrowband, across a number of frequency band channels on a wider electromagnetic spectrum. Benefits include improved privacy, decreased...