Term
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Definition
| In comparison to narrow band signal transmissions, SS spread the signal across several frequencies for transmission. |
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Term
| Name the two spread spectrum methodologies |
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Definition
| Frequency hopping and Direct sequence |
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Term
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Definition
| A particular sequence of 1s and 0s that has properties that make it ideal for modulating radio waves, as well as for being correctly detected by the receiver. |
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Term
| Another name for "Barker code" |
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Definition
| Chipping code or pseudo random code |
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Term
| When should the term barker code "correctly" be used to in describing Direct Sequence Spread Spectrum (DSSS)? |
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Definition
Barker code is correcty used only when reffering to 802/11 transmission at 1 and 2 Mbps.
WHen reffering to other spread spectrum codes used in DSSS (such as CDMA cell phones the term psuedo-random code (PN), spreading code and chipping code may be used interchang |
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Term
| Instead of x-mitting a single 1 or 0, what does DSSS sys x-mit? |
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Definition
| DSSS sys x-mits a combination of multiple chips. 11 chips are x-mitted at a rate 11 times faster than the data rate (the data rate does not change). The results of x-mitting the signal at a higher rate is the results of spreading the signal over a much wider freq band. With for example, 802.11 the signal is spread 11 MHz to each side of the center freq and ends up occupying a bandwidth of 22 MHz. |
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Term
| Instead of x-mitting a single 1 or 0, what does DSSS sys x-mit? |
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Definition
| DSSS sys x-mits a combination of multiple chips. 11 chips are x-mitted at a rate 11 times faster than the data rate (the data rate does not change). The results of x-mitting the signal at a higher rate is the results of spreading the signal over a much wider freq band. With for example, 802.11 the signal is spread 11 MHz to each side of the center freq and ends up occupying a bandwidth of 22 MHz. |
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