Spread Spectrum Transmission Comparison
Week 1 iLab Report
DeVry University
NETW360: Wireless Technologies and Services
OPNET Preparation and Spread Spectrum Transmission Comparison
Submitted to:
Professor:
Date: November 2, 2014
OPNET Preparation
OPNET Preparation
Paste your Windows Explorer screenshot that shows your Citrix NETW360 directory structure here. An example screenshot appears in your Week 1 iLab tab.
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 Transmission is a technique used for transmitting radio signals and other telecommunications signals. It is a modern component of CMDA technology used for cellphone signals, …show more content…
with having advantages in noise reduction, security and also is resistant to jamming and interceptions. It works by using wide band, noise signals, and because they are wide, it can transmit lower spectral density (Watts per Hertz).
Frequency Hopping Spread Spectrum (FHSS)
Guidelines
What is it?
How does it work? What issues are addressed? Why is it important?
Frequency Hopping Spread Spectrum is a form of development of Spread Spectrum Transmission where signals are carried by carriers shifting across many channels. Issues addressed are since the hopping is wider than what is required to transmit information and only of small portion of the bandwidth is transmitted at a certain time, the interference bandwidth is really the same. Also it does not provide extra protection against wideband thermal noise, but it does reduce the interference caused by narrowband interferers.
Direct Sequence Spread Spectrum (DSSS)
Guidelines
What is it? How does it work? What issues are addressed? Why is it important?
DSSS is used for digital signal transmission over airwaves and used for resistance against jamming attempts. Also used for local area wireless network transmissions with a data signal at the sender being combined with a high data rate bit sequence. So in other words it does not spread when the signal is being sent. The way it works is being spread out if there is an interference jammer in the same band.
Comparison between FHSS and DSSS
Technique …show more content…
Advantages
Disadvantages
FHSS FHSS systems are the cheapest, and easiest to implement.
FHSS radio systems do better indoors and in severe multipath environments. This is because the frequency hopping scheme can defeat multipath by just hopping to a new frequency.
Processing gain
Jamming resistance
Multiple access capability
Lowest potential data rates (2Mbps) from individual physical layers
Less range than direct sequence because of need for at least 18dB SNR at the receiver.
Potential obsolescence as more companies continue to favor the higher-speed (802.11b) direct sequence products
DSSS
DSSS are much more useful in outdoor and non-cluttered environments.
Uses their bandwidth more efficiently can result in a much higher data throughput
Requires a DSP, linear IQ modulation, IQ spin control, and linear (class A or AB RF power amplification. Along with precise linear amplification of all up/down converters and low noise amplifiers. All these circuits also need to have 22 MHz of bandwidth.
Less tolerance of signal interference because of operation over narrower (20MHz) bandwidth.
Lower aggregate throughput using collocated access points (1 or 2Mbps versions).
Guidelines: Summarize what was learned in a concise table format.
Conclusion
Guidelines: Minimum one paragraph; best practice is two or more paragraphs
What did you learn? How does it relate to this week’s TCOs and course material? Why is it important? How do you feel it will benefit you in your academic and professional career?
References
EE Times. (2003, May 6). Tutorial on Spread Spectrum Technology | EE Times. Retrieved from http://www.eetimes.com/document.asp?doc_id=1271899
InformIT. (2000, November 29). IEEE 802.11 Direct Sequence Spread Spectrum (DSSS) | IEEE 802.11 Standard Overview | InformIT. Retrieved from http://www.informit.com/articles/article.aspx?p=19825&seqNum=5
Spread Spectrum. (n.d.). ABCs of Spread Spectrum - A Technology Introduction and Tutorial. Retrieved from http://sss-mag.com/ss.html
Techopedia. (n.d.). What is Frequency Hopping Spread Spectrum (FHSS)? - Definition from Techopedia. Retrieved from http://www.techopedia.com/definition/25709/frequency-hopping-spread-spectrum-fhss
DeVry University
NETW360: Wireless Technologies and Services
OPNET Preparation and Spread Spectrum Transmission Comparison
Submitted to:
Professor:
Date: November 2, 2014
OPNET Preparation
OPNET Preparation
Paste your Windows Explorer screenshot that shows your Citrix NETW360 directory structure here. An example screenshot appears in your Week 1 iLab tab.
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 Transmission is a technique used for transmitting radio signals and other telecommunications signals. It is a modern component of CMDA technology used for cellphone signals, …show more content…
with having advantages in noise reduction, security and also is resistant to jamming and interceptions. It works by using wide band, noise signals, and because they are wide, it can transmit lower spectral density (Watts per Hertz).
Frequency Hopping Spread Spectrum (FHSS)
Guidelines
What is it?
How does it work? What issues are addressed? Why is it important?
Frequency Hopping Spread Spectrum is a form of development of Spread Spectrum Transmission where signals are carried by carriers shifting across many channels. Issues addressed are since the hopping is wider than what is required to transmit information and only of small portion of the bandwidth is transmitted at a certain time, the interference bandwidth is really the same. Also it does not provide extra protection against wideband thermal noise, but it does reduce the interference caused by narrowband interferers.
Direct Sequence Spread Spectrum (DSSS)
Guidelines
What is it? How does it work? What issues are addressed? Why is it important?
DSSS is used for digital signal transmission over airwaves and used for resistance against jamming attempts. Also used for local area wireless network transmissions with a data signal at the sender being combined with a high data rate bit sequence. So in other words it does not spread when the signal is being sent. The way it works is being spread out if there is an interference jammer in the same band.
Comparison between FHSS and DSSS
Technique …show more content…
Advantages
Disadvantages
FHSS FHSS systems are the cheapest, and easiest to implement.
FHSS radio systems do better indoors and in severe multipath environments. This is because the frequency hopping scheme can defeat multipath by just hopping to a new frequency.
Processing gain
Jamming resistance
Multiple access capability
Lowest potential data rates (2Mbps) from individual physical layers
Less range than direct sequence because of need for at least 18dB SNR at the receiver.
Potential obsolescence as more companies continue to favor the higher-speed (802.11b) direct sequence products
DSSS
DSSS are much more useful in outdoor and non-cluttered environments.
Uses their bandwidth more efficiently can result in a much higher data throughput
Requires a DSP, linear IQ modulation, IQ spin control, and linear (class A or AB RF power amplification. Along with precise linear amplification of all up/down converters and low noise amplifiers. All these circuits also need to have 22 MHz of bandwidth.
Less tolerance of signal interference because of operation over narrower (20MHz) bandwidth.
Lower aggregate throughput using collocated access points (1 or 2Mbps versions).
Guidelines: Summarize what was learned in a concise table format.
Conclusion
Guidelines: Minimum one paragraph; best practice is two or more paragraphs
What did you learn? How does it relate to this week’s TCOs and course material? Why is it important? How do you feel it will benefit you in your academic and professional career?
References
EE Times. (2003, May 6). Tutorial on Spread Spectrum Technology | EE Times. Retrieved from http://www.eetimes.com/document.asp?doc_id=1271899
InformIT. (2000, November 29). IEEE 802.11 Direct Sequence Spread Spectrum (DSSS) | IEEE 802.11 Standard Overview | InformIT. Retrieved from http://www.informit.com/articles/article.aspx?p=19825&seqNum=5
Spread Spectrum. (n.d.). ABCs of Spread Spectrum - A Technology Introduction and Tutorial. Retrieved from http://sss-mag.com/ss.html
Techopedia. (n.d.). What is Frequency Hopping Spread Spectrum (FHSS)? - Definition from Techopedia. Retrieved from http://www.techopedia.com/definition/25709/frequency-hopping-spread-spectrum-fhss