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In digital communications, chirp spread spectrum (CSS) is a spread spectrum technique that uses wideband linear frequency modulated chirp pulses to encode information. [1] A chirp is a sinusoidal signal whose frequency increases or decreases over time (often with a polynomial expression for the relationship between time and frequency).
A chirp is a signal in which the frequency increases (up-chirp) or decreases (down-chirp) with time. In some sources, the term chirp is used interchangeably with sweep signal. [1] It is commonly applied to sonar, radar, and laser systems, and to other applications, such as in spread-spectrum communications (see chirp spread spectrum). This ...
Moreover, for a given noise power spectral density (PSD), spread-spectrum systems require the same amount of energy per bit before spreading as narrowband systems and therefore the same amount of power if the bitrate before spreading is the same, but since the signal power is spread over a large bandwidth, the signal PSD is much lower — often ...
The spectrum of a chirp pulse describes its characteristics in terms of its frequency components. This frequency-domain representation is an alternative to the more familiar time-domain waveform, and the two versions are mathematically related by the Fourier transform.
DASH7, a low latency, bi-directional firmware standard that operates over multiple LPWAN radio technologies including LoRa. Wize is an open and royalty-free standard for LPWAN derived from the European Standard Wireless Mbus. [3] Chirp spread spectrum (CSS) based devices. Sigfox, UNB-based technology and French company. [4]
IEEE 802.15.4c was approved in 2008 and was published in January 2009. This defines a PHY amendment that adds new RF spectrum specifications to address the Chinese regulatory changes which have opened the 314-316 MHz, 430-434 MHz, and 779-787 MHz bands for Wireless PAN use within China.
ISO/IEC 24730-2:2012 Information technology — Real time locating systems (RTLS) — Part 2: Direct Sequence Spread Spectrum (DSSS) 2,4 GHz air interface protocol ISO/IEC 24730-5:2010 Information technology — Real-time locating systems (RTLS) — Part 5: Chirp spread spectrum (CSS) at 2,4 GHz air interface
IEEE 802.15.4 protocol stack. Devices are designed to interact with each other over a conceptually simple wireless network.The definition of the network layers is based on the OSI model; although only the lower layers are defined in the standard, interaction with upper layers is intended, possibly using an IEEE 802.2 logical link control sublayer accessing the MAC through a convergence sublayer.