# uwb Vs. Spread Spectrum communication

Discussion in 'General Electronics Chat' started by vinodquilon, Oct 16, 2010.

1. ### vinodquilon Thread Starter Member

Dec 24, 2009
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Both UWB & Spread Spectrum are using in wider bandwidth communication.
What is the difference between two ?

If we increase the Bandwidth, then power level will be too small. Then there is a probability to interpret the received signals as noise or affecting the transmitted signals by channel noise. How we can get rid of this problem ?

2. ### Potato Pudding Well-Known Member

Jun 11, 2010
684
92
That stuff has a lot of application in black op transmitters.

The main ways to get rid of the problems are phased array antennas.

3. ### Potato Pudding Well-Known Member

Jun 11, 2010
684
92
Ultra-Wideband (UWB) may be used to refer to any radio technology having bandwidth exceeding the lesser of 500 MHz or 20% of the arithmetic center frequency

Spread Spectrum is a type of artificial wideband created some of for various reasons.

4. ### samsmaths New Member

May 8, 2011
10
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Is this question a logical question? In other words why should i compare between UWB & SS? Yes, the question is a logical question because both signals share the same expanded bandwidth [1] .
Although UWB and spread-spectrum techniques share the same advantage of expanded bandwidth, the method of achieving the large bandwidth is the main distinction between the two technologies. In conventional spread-spectrum techniques, the signals are continuous-wave sinusoids that are modulated with a fixed carrier frequency. In UWB communications, on the other hand, there is no carrier frequency; the short duration of UWB pulses directly generates an extremely wide bandwidth [2]
In UWB, the short duration of a pulse automatically creates the very large bandwidth of several gigahertz without using the spreading codes. Also, notice that narrowband signals are always present, so their duty cycle is 100 percent, while UWB pulses are present only for a very short time, with a duty cycle of less than 0.5 percent. [3]
he low duty cycle offers very low transmission power and extra covertness compared to spread-spectrum techniques. However, the low transmission power could be a disadvantage for UWB systems, because the information can travel only short distances. Therefore, for long-range applications, spread-spectrum techniques are still more appropriate.[4]

Reference:
[1, 2, 3, 4] Ultra-Wideband Communications: Fundamentals and Applications: Fundamentals and ApplicationsBy Faranak Nekoogar

5. ### samsmaths New Member

May 8, 2011
10
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Imagine you want to carry something so heavy for a long distance, how much power and effort is needed? The signal carries a lot of information with low power; however some research is going on in shaping and trying to allow the UWB signal to go above noise floor. Combining UWB signal with PN time to code interpret the signal to a noise one, which has an advantage in favour for security, regarding the receiver use Rake receiver