The emergence and popularization of LoRa spread spectrum technology can be traced back to Semtech.
LoRa spread spectrum technology (LoRa spread spectrum technology) uses a special modulation technique called spread spectrum modulation (spread spectrum modulation) to achieve long-distance, low-power wireless communication.
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LoRa (Long Range) technology was first proposed by Semtech in 2013. Semtech is a semiconductor solutions provider focused on wireless communication and scalability solutions. They developed a new type of wireless communication technology, LoRa spread spectrum technology, which aims to address the needs of long-distance communication and low power consumption in IoT applications.
Establishment of open standards and ecosystems: Semtech regards LoRa technology as an open standard and promotes the establishment of the LoRa Alliance (LoRa Alliance). The alliance is composed of companies from various industries around the world and is committed to promoting the development of LoRa technology and the ecosystem. Alliance members include chip manufacturers, equipment manufacturers, service providers, system integrators, and application developers.
Technology promotion and application landing: With the establishment of the LoRa Alliance, LoRa spread spectrum technology began to be promoted and applied in the field of the Internet of Things. Alliance members have cooperated to develop various LoRa-related chips, modules and solutions, providing complete hardware and software support for IoT applications. LoRa technology is widely used in remote monitoring, smart cities, agriculture, industrial automation, and smart homes.
Growth of the Ecosystem: Over time, the ecosystem of LoRa Technology has continued to grow. More and more manufacturers and developers have joined the LoRa Alliance to promote the further development and innovation of LoRa technology. This includes launching LoRa chips and modules with more functions and performance, developing more application cases and solutions, and promoting the deployment and coverage expansion of LoRa networks
Principle of LoRa Spread Spectrum Technology
LoRa spread spectrum technology (LoRa spread spectrum technology) uses a special modulation technique called spread spectrum modulation (spread spectrum modulation) to achieve long-distance, low-power wireless communication. The following is the detailed principle of LoRa spread spectrum technology:
Modulation method: LoRa uses a modulation method called "Chirp". Chirp is a chirp signal whose frequency varies linearly with time. The sender converts the data to be sent into a series of Chirp signals and expresses different data by changing the frequency of the Chirp.
Spread spectrum: Before sending, the Chirp signal to be sent will be processed by spread spectrum technology. Spread spectrum is to spread the low-speed data stream over a wider frequency band to reduce the power density of a single signal. The spreading factor (Spreading Factor) used by LoRa can range from 7 to 12, which determines the degree of spreading. A higher spreading factor will reduce the signal transmission rate, but it can provide better anti-interference ability and longer communication distance.
Frequency selection: LoRa uses multiple available frequency channels, allowing multiple devices to communicate at the same time, reducing the possibility of mutual interference. Both parties communicate on the same frequency channel to ensure reliable data transmission.
Reception and demodulation: After receiving the LoRa signal, the receiver will perform the demodulation and despreading process. Demodulation converts the received signal to baseband while despreading restores the signal to the original spread spectrum signal. The demodulation and despreading process involves frequency and time synchronization of the signal.
Code rate and error correction: LoRa supports a variable code rate, which can be adjusted according to communication distance and communication quality requirements. At the same time, LoRa also has a built-in error correction coding function to improve data reliability. By using forward error correction (Forward Error Correction) technology, the receiver can recover some erroneous data, thereby improving the reliability of communication.
Is LoRa spread spectrum technology limited to LoRa modules?
LoRa spread spectrum technology is primarily associated with LoRa modules, which are specialized transceiver modules designed to support LoRa communication. These modules integrate the necessary hardware and software components to enable LoRa wireless communication. sist of a transceiver chip that implements the LoRa modulation scheme and a microcontroller for handling data processing and interfacing with other devices.
However, it's worth noting that LoRa technology is not exclusive to dedicated LoRa modules. The LoRa modulation scheme can be implemented in various ways, including using software-defined radios (SDR) or custom hardware designs. In such cases, the LoRa spread spectrum technology can be implemented on different platforms beyond dedicated LoRa modules, allowing flexibility in designing LoRa-based communication systems.
In summary, while LoRa spread spectrum technology is commonly associated with LoRa modules, it can also be implemented on other platforms, such as SDR or custom hardware, to achieve LoRa communication capabilities.
Common communication technologies combined with LoRa spread spectrum technology
Through integration with other technologies, LoRa spread spectrum technology can better meet the needs of IoT applications and expand its functions and application range. The flexibility of integrating different technologies makes LoRa more adaptable and scalable in various IoT scenarios.
LoRa spread spectrum technology is usually integrated with other technologies to meet the needs of different application scenarios.
LoRaWAN: LoRaWAN is a communication protocol based on LoRa spread spectrum technology, which defines the communication interface and protocol specifications between devices and network servers. LoRaWAN provides functions such as network management, security authentication, and data transmission, making LoRa spread spectrum technology easier to deploy and manage.
MQTT (Message Queuing Telemetry Transport): MQTT is a lightweight publish/subscribe message transport protocol, often used in combination with LoRa spread spectrum technology. By connecting the LoRa device with the MQTT proxy server, the message publication and subscription between the devices can be realized, and real-time data transmission and remote control can be realized.
GPS (Global Positioning System): GPS positioning technology can be combined with LoRa spread spectrum technology to locate and track the location information of mobile devices. By combining a GPS receiver with a LoRa module, location tracking, geo-fencing and location-related applications of IoT devices can be realized.
Edge computing: Edge computing is a method of moving computing and data processing capabilities to the edge of the network, which can be combined with LoRa spread spectrum technology to provide more efficient data processing and decision-making capabilities. Edge computing nodes can process and analyze received data in real-time by directly interacting with LoRa devices, reducing dependence on central servers.
Solar/battery-powered system: Due to the low power consumption characteristics of LoRa spread spectrum technology, it is often used in combination with solar or battery-powered systems. This enables LoRa devices to run for a long time without frequent battery replacement or external power supply, suitable for remote, outdoor, or difficult-to-obtain power application scenarios.
The reason why LoRa spread spectrum technology is frequently used in wireless communication is that it has the following advantages:
Long-distance transmission: LoRa spread spectrum technology can achieve long-distance transmission under low power conditions, with good penetration and coverage. This makes it ideal for wide-area IoT (LPWAN) applications such as urban smart grids, agricultural monitoring, and industrial IoT, among others.
Low power consumption: LoRa spread spectrum technology can achieve long battery life with low power consumption. This is critical for many IoT devices, as they are often required to run for long periods of time without batteries that can be easily replaced.
Strong anti-interference ability: LoRa spread spectrum technology adopts an anti-interference modulation scheme, which can effectively deal with interference factors such as noise and multipath propagation. This enables LoRa devices to perform well in complex wireless environments and provide reliable communication connections.
Multi-device connection: LoRa spread spectrum technology supports a large number of devices to connect to the same base station at the same time, with excellent multiple access capabilities. This enables the LoRa network to carry large-scale IoT devices for efficient data transmission and centralized management.