Nanotron Technologies GmbH
embedded location platform
Company
Products
Solutions
Support
Careers
Press
Home
Sales  | Contact
Overview
Team
Investors
Technology
Standards
protect with swarm
find with nanoRTL
Transceiver
Collision Avoidance
Robotics
Proximity Authentication
Smart Machines
Mining and Tunnels
Work Safety
Livestock Management
Workflow Management
Product Developers
System Integrators
Nanotron eLibrary Login
Jobs
Students
News
About Nanotron
Events

nanotron's Technology

Chirp Spread Spectrum (CSS)

Chirp Spread Spectrum (CSS) is a customized application of MDMA for the requirements of battery–powered applications, where the reliability of the transmission as well as low power consumption are of special importance. CSS forms the basis of the nanoLOC TRX Transceiver which was developed for medium data rate applications. CSS consists of Chirp pulses, an Upchirp and a Downchip, as illustrated below.

Upchirp and Downchirp
Chirp Spread Spectrum

Key Features of CSS

  • Robust against disturbances
  • Robust against multipath fading
  • Low power consumption
  • Easy to implement in silicon

About Chirp Pulses

Chirp pulses are:

  • Robust against Noise and Multipath Fading due to high BT Product
  • Most effective Utilization of the given Bandwidth
  • Simple Synchronization

CSS operates in the 2.45 GHz ISM band and achieves a maximum data rate of 2 Mbps. Each symbol is transmitted with a chirp pulse that has a bandwidth of 80 MHz (an effective bandwidth of 64 MHz is the result of a selected roll-off factor of 0.25) and a fixed duration of 1 µs. The system gain of CSS is 17 dB.

Chirp Pulses can simply be used as Spread Spectrum Signals:

Chirp Pulses
Chirp Pulses
Chirp pulses

Chirp pulses are used in nature by Dolphins and Bats. These pulses were first patented for radar applications during 1940 by Prof. Hüttmann, and was further developed by Sidney Darlington (Lifetime IEEE Fellow) in 1947 (”Pulse Compression Radar“). During the mid 1990s Canon patented chirp pulses for data transmission in fiber optic systems. Since 1996, CSS for commercial wireless data transmission was investigated and patented by nanotron Technologies.

Benefits of CSS

The use of the robust chirp pulse in CSS significantly reduces the required transmission power that is needed for transmission over a given distance. This reduces the human exposure drastically (“electro smog”). No scientific research has proven the negative effects of electromagnetic exposure for human beings but the public acceptance for new wireless services with less transmission power will increase. Other benefits of CSS include:

  • CSS is Resistant Against Narrowband Disturbances
    Because it uses broadband chirp pulses, CSS is very resistant against disturbances. Click here to view a diagram showing the effect of narrowband noise with a signal-to-noise ratio (SNR) of 0 dB. The signal is reinforced by the dispersive delay line (DDL) while the disturbances contribute only as basic noise (system gain). Therefore, CSS is very resistant against narrowband noise.
  • CSS is Resistant Against Narrowband Disturbances
    Narrowband noise with a signal-to-noise ratio (SNR) of 0 dB
  • CSS is Resistant Against Broadband Disturbances
    CSS is resistant even against broadband disturbances. The diagram below shows the effects of broadband disturbances at SNR of 0 dB. The DLL effects a significant reduction of the noise with respect to the signal. With this, CSS is most suitable for the highly used ISM band where interference from other communication services and microwave ovens create massive disturbances.
    CSS is Resistant Against Broadband Disturbances
    Broadband disturbances at SNR of 0 dB
  • CSS is Robust Against Multipath Fading
    Another significant advantage of CSS is its robustness against multipath fading. The original signal from the transmitter reaches the receiver with several echoes and reflections from buildings and other environmental surroundings due to multipath propagation. The reflections reach the receiver in or out of phase. Some frequencies will be amplified or attenuated depending on the conditions. This leads to a disconnection of the communication link of narrowband transmission systems. CSS is different, however, in that the amplified and attenuated signals are in balance because all energy shares (which are spread over the bandwidth of 80 MHz) are collected (integrated broadband technique).

 


CSS FAQ

What are the Advantages and Benefits of Chirp Signals?
How do nanotron systems achieve a higher range with lower transmission power?
nanotron's wireless technology is marketed as having "high robustness" and is called the "wireless wire". Why should the noise immunity of nanotron's systems be better as compared to other systems?
Chirp Signals are claimed to have extremely low human exposure. How is this possible?
In nanoLOC Chirp signaling is applied to measure the distance between transceivers. What is the advantage and what is the time accuracy between nodes?
What is meant by the multi access system "MDMA" developed by nanotron and what are its advantages?
What happens when the transmitter and the receiver come very close together, such as 0.3 m, or when the receiver is very far away, such as 100 m, which is the so called "near-far problem"?
How do Chirp signals tolerate multi-path effects?
What is the difference between nanoLOC and nanoNET?
nanotron has claimed that its systems are able to exploit transmission parameters (bandwidth, power and time) to an optimal extent. What does this mean?
Is the system concept of nanotron's wireless technology transferable also to other frequency bands such as 868 M Hz?
What is the estimate for further development of this technology in the next 3 to 10 years (with respect to range, data rate, receiver sensitivity, robustness in the crowded 2.4 GHz band, accuracy of distance measurement, and cost for each node)?
What happens if several independent CSS systems (i.e. of different suppliers) with diverse data rates are running in the same transmission area?
Is coexistence with DSM technology of Spectrum possible?
Which applications are best suited for nanotron's wireless technology?

 

...reliable, efficient, visible.