Chirp spread spectrum
| Passband modulation |
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| Analog modulation |
| Digital modulation |
| Hierarchical modulation |
| Spread spectrum |
| See also |
| Multiplexing |
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| Analog modulation |
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Statistical multiplexing (variable bandwidth) |
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| Related topics |
In digital communications, chirp spread spectrum (CSS) is a
Overview
As with other spread spectrum methods, chirp spread spectrum uses its entire allocated bandwidth to broadcast a signal, making it robust to channel noise. Further, because the chirps utilize a broad band of the spectrum, chirp spread spectrum is also resistant to multi-path fading even when operating at very low power. However, it is unlike direct-sequence spread spectrum (DSSS) or frequency-hopping spread spectrum (FHSS) in that it does not add any pseudo-random elements to the signal to help distinguish it from noise on the channel, instead relying on the linear nature of the chirp pulse. Additionally, chirp spread spectrum is resistant to the Doppler effect, which is typical in mobile radio applications.[2]
Uses
Chirp spread spectrum was originally designed to compete with ultra-wideband for precision ranging and low-rate wireless networks in the 2.45 GHz band. However, since the release of IEEE 802.15.4a (also known as IEEE 802.15.4a-2007), it is no longer actively being considered by the IEEE for standardization in the area of precision ranging.
Chirp spread spectrum is ideal for applications requiring low power usage and needing relatively low data rates (1 Mbit/s or less). In particular, IEEE 802.15.4a specifies CSS as a technique for use in low-rate
Chirp spread spectrum may also be used in the future for military applications as it is very difficult to detect and intercept when operating at low power.[5]
Very similar frequency swept waveforms are used in
One application of chirp spread spectrum is LoRa.[6][7]
See also
- Bluetooth
- IEEE 802.11
- IEEE 802.15.4
- IEEE 802.15.4a
- IEEE 802.16
- IEEE 802.20
- IEEE 802.22
- Spectral efficiency comparison table
- Zigbee
References
- ^ IEEE Computer Society, (August 31, 2007). IEEE Standard 802.15.4a-2007. New York, NY: IEEE.
- ^ Berni, A. J., & Gregg, W. D. (June 1973). On the utility of chirp modulation for digital signaling, IEEE Transactions on Communications. Volume COM-21, 748-751
- ^ http://www.autoid.org/SC31/wg5/06/WG5_200603_010_InfoCSS.ppt Archived 2007-10-21 at the Wayback Machine , Nanotron Mine Test: slide 22
- ^ Nanotron Technologies, (2007). nanoNET chirp based wireless networks. Retrieved from http://www.nanotron.com/EN/docs/WP/WP_CSS.pdf[permanent dead link]
- ^ The Revenge of Chirp Spread Spectrum, Military applications Archived 2008-05-15 at the Wayback Machine
- ^ "RF Modulation: Crash Course for Hackers". 28 January 2020.
- S2CID 69444615.
External links
- Download the 802.15 standards from IEEE
- IEEE 802.15 WPAN Low Rate Alternative PHY Task Group 4a (TG4a)
- Nanotron Technologies Frequently asked Questions page
- Nanotron Chirp Spread Spectrum page
- Nanotron nanoNET Chirp Based Wireless Networks[permanent dead link]
- About coexistence of IEEE 802.15.4aCSS with IEEE 802.11b/g (2.45 GHz WLAN)