UWB (Ultra Wide Band) is a wireless carrier communication technology that uses frequency bandwidth above 1GHz. It does not use sinusoidal carrier in traditional communication system, but uses narrow pulse of non-sinusoidal wave at nanosecond level to transmit data. Therefore, it occupies a large spectrum. But data transfer rates can reach hundreds of megabits per second or more.
UWB technology has the advantages of low system complexity, low transmitting signal power spectral density, insensitivity to channel fading, low interception ability, high positioning accuracy and strong penetration ability, especially suitable for high-speed wireless access in dense multi-path places such as indoor.
Wi-Fi and Bluetooth are typically located using received signal strength indicators (RSSI), which show only rough categories of "weak" or "strong" received signals, with positioning accuracy up to meters.
There are three technologies for UWB positioning, namely TOF (Time of Flight), TDOA (Time Difference of Arrival) and PDOA (Phase Difference of Arrival). Although this is only suitable for shorter ranges, the location of the signal source can be determined with an accuracy of less than 50 cm (under optimal conditions and deployment) and extremely low latency.
The advantages of UWB technology are:
1, High positioning accuracy: very wide bandwidth, strong multipath resolution, anti-interference, for distance resolution than Wi-Fi and Bluetooth.
2, Real-time positioning speed: UWB ultra-wideband pulse signal bandwidth in nanosecond level, can achieve real-time indoor positioning, low delay, can immediately perceive and track the motion of the object.
3. High reliability and security: The transmission power of UWB is low and the signal band is wide, which can be well concealed in other types of signals and environmental noise. Traditional receivers cannot recognize and receive it, so the demodulation can only be carried out by using the spread spectrum code pulse sequence consistent with the transmitter.
The three technologies of UWB, Wi-Fi and Bluetooth do not exist in isolation. They can be used at the same time and complement each other with their advantages. They can bring positioning and data transmission services with various requirements to terminal products such as smart phones, and have higher requirements for relevant antenna and RF design.