As Xiaomi’s first under-screen camera flagship, Xiaomi Mi MIX 4 has attracted many consumers’ attention since its release. This smartphone is the first device in the Xiaomi Mi MIX series since 2018. Although we saw devices like the Xiaomi Mi MIX Alpha and Xiaomi Mi MIX Fold, these are not regular smartphones. Besides, the Xiaomi Mi MIX 4 is the direct successor to the 2018 Xiaomi Mi MIX 3. After three years, Xiaomi Mi MIX 4 not only brings an amazing full-screen CUP, it is also Xiaomi’s first smartphone to use the UWB one-finger connection technology.
Less than a year after the technology was released, Xiaomi UWB has already been mass-produced on Xiaomi Mi MIX 4. Compared with traditional Wi-Fi and Bluetooth-based positioning methods based on signal strength, what are the advantages of UWB technology? How does it achieve its new standards? In this regard, Xiaomi officially launched a popular science discussion on the UWB technology today.
According to the company, UWB technology can perform precise 3D positioning of the device in space. When used with the Mi TV Master 77″ OLED or Mi One Finger Connect, the mobile phone can be pointed at the TV and the operation interface will pop up.
Ultra-Wideband (UWB) is different from other wireless technologies. Its operating frequency range is wider, between 6GHz – 8.5GHz. Furthermore, the signal which it reflects in the time domain is an ultrashort pulse of only about 2 nanoseconds.
Advantages of the ultrashort pulse
Its ultrashort pulse characteristics bring three advantages:
The first is the high degree of recognition, because the characteristics are obvious, the UWB receiver can recognize UWB pulses from a noisy signal. This allows UWB to use lower transmit power, usually 30dBm lower than Wi-Fi signals. The signal can also hide in the “background noise” thereby causing almost no interference. Therefore, the UWB one-finger connection function of the MIX 4 will not affect the normal operation of radio frequencies such as Wi-Fi, Bluetooth, and 5G.
Secondly, due to the extremely short pulse, Xiaomi Mi MIX 4 can quickly determine the distance of AIoT devices. It does this usually within a range of 10m and the error is only 20cm. Thus, it can effectively filter surrounding devices, such as activating only the closest AIoT device to the user.
Not only that, through the three receiving antennas on the Xiaomi Mi MIX 4, AIoT devices can be positioned in 3D. With this, the polar coordinates (longitudinal angle, latitude angle, and distance) can be reported for upper-layer applications. The user can also accurately determine which AIoT device it is pointing to. Furthermore, the connection is seamless and it takes only 20ms to complete a positioning.