Table of Contents
What is chirp spread spectrum modulation?
Chirp, or Chirp Spread Spectrum (CSS), is a long-range radio-frequency technology for wireless communication that can be leveraged to detect and track the location of people, assets, and devices both in and outdoors, across large-scale facilities.
What is a LoRa symbol?
LoRa uses three different bandwidth: 125kHz, 250kHz and 500kHz (125kHz is used here). LoRa symbols are modulated over a up-chirp of 125kHz bandwidth and different orthogonal (almost) spreading factors are used based on data rate requirement and channel conditions. LoRa uses SF7 to SF12 spreading factors.
Why spread spectrum is required?
The main advantage of spread spectrum communication technique is to prevent “interference” whether it is intentional or unintentional. The signals modulated with these techniques are hard to interfere and cannot be jammed. An intruder with no official access is never allowed to crack them.
Why do we use spread spectrum?
What is the bandwidth of LoRa?
A proprietary spread-spectrum modulation technique derived from existing Chirp Spread Spectrum (CSS) technology, LoRa offers a trade-off between sensitivity and data rate, while operating in a fixed-bandwidth channel of either 125 KHz or 500 KHz (for uplink channels), and 500 KHz (for downlink channels).
What is coding rate in LoRa?
The coding rate refers to the proportion of transmitted bits that actually carry information. Coding rate can be 6/8, 4/8, etc… So if CR is 4/8 we are transmitting twice as many bits as the ones containing information.
Is spectrum a GSM or CDMA?
Does Spectrum Mobile use CDMA or GSM? Verizon uses the CDMA network so Spectrum Mobile is compatible with all CDMA phones. Don’t worry if your phone is not using the same technology, you can still save money on your cell phone plan. If you want to check your phone’s compatibility you can use our IMEI checker.
What modulation does LoRa use?
LoRa is a wireless modulation technique derived from Chirp Spread Spectrum (CSS) technology. It encodes information on radio waves using chirp pulses – similar to the way dolphins and bats communicate! LoRa modulated transmission is robust against disturbances and can be received across great distances.
What protocol does LoRa use?
LoRaWAN is a point-to-multipoint networking protocol that uses Semtech’s LoRa modulation scheme. It is not just about the radio waves; it’s about how the radio waves communicate with LoRaWAN gateways to do things like encryption and identification.
What is Preamble in LoRa?
Thus, LoRa introduces a preamble of a few symbols (typically, eight). In uplink communications, the preamble consists of up-chirps and the data consists of down-chirps. In downlink communications, the preamble consists of down-chirps and the data consists of up-chirps.
What is the block diagram of Spread Spectrum digital communication?
The block diagram of spread spectrum digital communication is shown in above fig. the basic elements of a spread spectrum digital communication system with a binary information sequence at its input at the transmitting end and its output at the receiving end.
What is CSS (Chirp Spread spectrum)?
In digital communications, chirp spread spectrum (CSS) is a spread spectrum technique that uses wideband linear frequency modulated chirp pulses to encode information.
What is an upchirp spread spectrum?
Chirp spread spectrum. A chirp is a sinusoidal signal of frequency increase or decrease over time (often with a polynomial expression for the relationship between time and frequency). In the picture is an example of an upchirp in which the frequency increases linearly over time. Sometimes the frequency of upchirps increase exponentially over time.
What is linear frequency modulated upchirp?
A linear frequency modulated upchirp in the time domain. Other types of upchirps may increase exponentially over time. In digital communications, chirp spread spectrum ( CSS) is a spread spectrum technique that uses wideband linear frequency modulated chirp pulses to encode information.